Palocz Andresen2013
Palocz Andresen2013
Decreasing Fuel
Consumption and
Exhaust Gas Emissions
in Transportation
Sensing, Control and Reduction
of Emissions
123
Michael Palocz-Andresen
UCS Umweltconsulting
Hamburg
Germany
Since 1998, the introduction of the first Directive with On-Board Measurement in
the EU, many parameters in transport have changed. Both the population of the
world and the demand for transportation have been continuously increasing.
Transport has become the basic foundation of the economy in all countries. In the
course of this process, the environment and the climate have been changing in a
remarkable way and in turn have influenced transport.
Environmental legislation with Directives such as 98/69/EU, 99/96/EU, and
finally 582/2011/EC with amendments, is already reducing emissions of individual
vehicles. However, the number of motor vehicles, ships, and airplanes is rapidly
rising, especially in fast developing countries. Parallel to this, the amount of oil
products consumed and the mass of pollutants emitted are intensively increasing.
A new, sustainable path is required, which focuses on reasonable mass transport at
a reasonable price, short travel times with optimal connections, positive impacts in
safety, and improvements in sustainability. Good examples are needed worldwide.
Transportation could be improved with the introduction of carbon taxes, higher
fuel efficiency standards and the use of new kinds of fuels. It is not enough to
produce biogenic and synthetic fuels, although they can be optimally used in road
vehicles, airplanes and ships, because they have their own additional problems. On
the one side, their utilization lowers the consumption of fossil fuels, but on the
other side, their exaggerated use could contribute to the destruction of agriculture
and the landscape.
Transport burns most of the petroleum of the world and emits the most air
pollution, including unburned hydrocarbons, carbon monoxide, nitrous oxides, and
particles. It is the fastest growing consumption and emission sector on Earth. This
leads to significant environmental and health problems especially in large cities
and is a major contributor to global warming because of emissions of carbon
dioxide. New urban infrastructure needs to primarily foster environmentally
friendly modes and better management of transportation.
Vehicles, airplanes and ships are becoming more and more efficient, i.e., lighter
and more intelligent, with improved aerodynamics, optimized design, and higher
v
vi Preface
Three years ago, 2008, my first book concerning On-Board Measurement was
published by the Expert Verlag in Renningen, Germany. In that book the basic
fundamentals of direct measurement technology (OBM) were described. Since that
time, the legislation and the technology have been intensively developed. It seems to
be necessary, to continue the work. The next logical stage of On-Board Measurement
is Self Diagnosis (SD) which is the centre of consideration in this book.
This is the result of three and a half years of work. Special thanks go to the
researchers and teachers, scientists and professors of Leuphana University Lüneburg
for the invaluable advice and support regarding sustainable transportation.
The consortium of the University of West-Hungary Sopron supported several
application-oriented sections in research and presentation and also gave important
assistance.
Within my own team, I would like to express my gratitude to Mr. János Székely
(Budapest), Mr. Balázs Szegedi, Ms. Luca Héjja, and Mr. Gergely Krizbai (Sopron)
for their efforts in the area of design, Mrs. Dóra Szalay (Sopron) for her support in
the construction and checking of units and conversions in the book, and Dr. Hartmut
Mädler and Mr. Ulrich Gross (Hamburg) in the translation of subtexts in the
international literature and creation of subject indices.
I would also like to heartily thank Dr. Huba Németh (Budapest) for his kind
assistance and cooperation with regard to road technology.
I am also grateful to Mr. Károly Galvácsy and Mr. János Mikulás (Budapest)
for their support in the development of aviation and for many interesting discus-
sions regarding safety, aircraft inspection, and maintenance and air traffic
emissions.
Concerning the shipping experiments undertaken for the purpose of this book,
Mr. Joachim Goetze (Hamburg) and Mr. Csaba Hargitai (Budapest) were also
extremely helpful.
vii
viii Acknowledgments
And finally, many thanks to Dr. Richard von Fuchs (Sopron) and Mr. David
Carolan Kômoto (Hamburg) for proofreading this book.
2 Fuels in Transportation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.1 Classification of Types of Fuels . . . . . . . . . . . . . . . . . . . . . . 13
2.2 Road Transport Fuels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.2.1 Gasoline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.2.2 Diesel Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.2.3 Reference Fuels . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.2.4 Products of Natural Gas . . . . . . . . . . . . . . . . . . . . . 18
2.2.5 Synthetic Fuels. . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.2.6 Biogenic Fuels . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.2.7 Blended Fuels . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2.3 Aviation Fuels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
2.3.1 Kerosene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
2.3.2 Testing Fuel for Engines . . . . . . . . . . . . . . . . . . . . . 24
ix
x Contents
5 Emissions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
5.1 Physical and Chemical Properties of Combustion Products . . . 81
5.2 Measurement of Emissions . . . . . . . . . . . . . . . . . . . . . . . . . 83
5.2.1 Measurement at Test Benches . . . . . . . . . . . . . . . . . 84
5.2.2 Measurement On-Board. . . . . . . . . . . . . . . . . . . . . . 85
5.2.3 Remote Sensing Technology . . . . . . . . . . . . . . . . . . 87
5.3 Emissions in Road Traffic . . . . . . . . . . . . . . . . . . . . . . . . . . 87
5.4 Emissions in Aviation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
5.5 Emissions in Ship Navigation . . . . . . . . . . . . . . . . . . . . . . . 90
5.6 Summary and Recommendations: Emissions
from Transportation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
5.6.1 Vehicle Emissions . . . . . . . . . . . . . . . . . . . . . . . . . 92
5.6.2 Airplane Emissions . . . . . . . . . . . . . . . . . . . . . . . . . 92
5.6.3 Ship Emissions. . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
14 Navigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
14.1 Road Transportation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
14.1.1 Ecologic Strategy of Navigation . . . . . . . . . . . . . . . . 211
14.1.2 Foresighted Driving . . . . . . . . . . . . . . . . . . . . . . . . 211
14.1.3 Convoy Travel with Heavy-Duty Vehicles. . . . . . . . . 212
Contents xv
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311
Abbreviations
xix
xx Abbreviations
The central topics of the book are fuel consumption and exhaust gas emission
saving technologies, monitoring possibilities, infrastructure impacts, administra-
tive and legislative options, and financial and social conditions in transportation.
This book has five main chapters (see Fig. 1.1).
All means of transport consume fuel and emit waste products into the air. The
fundamentals of recent technology are depicted in [1]. This book deals with fuel
consumption and exhaust gas emissions from internal combustion and jet engines
in motor vehicles, ships, and airplanes, and does not survey railroads, and it
furthermore considers unburned hydrocarbons, carbon monoxide, nitrogen mon-
oxide, nitrogen dioxide, particles and carbon dioxide, and does not include other
pollutants and climate gases.
Regarding the complexity of transport, the most important potentials for fuel
savings are in the technology of vehicles, airplanes and ships, in the organization
of transportation systems and in the optimization of environmental conditions,
which is the main guide for consideration in this book (see Fig. 1.2).
Fuel consumption of vehicles can be expressed using the metric unit system in
terms of consumed fuel per passenger kilometer and passenger mile or per weight
of transported cargo:
• Fuel volume or fuel mass per passenger-kilometers in l (passenger km)-1 or kg
(passenger kg)-1;
Types of fuel
Fundamental elements of saving
fuel and reducing emissions Measurement of fuel consumption
Construction
Propulsion technology
Engine technology
Navigation
Future transportation
Future transportation
systems
Closing remarks
• Fuel volume or fuel mass per freight mass and distance, or freight volume and
distance in l (kg km)-1 and l (m3 km)-1, or kg (kg km)-1 and kg (m3 km)-1;
and
• Fuel volume or fuel mass per engine performance or engine thrust as Specific
Fuel Consumption (SFC) in ml (kNh)-1 and ml (kWh)-1 or g (kNh)-1 and g
(kWh)-1.
Unlike the metric system (International System of Units (SI) or Système
International d’Unités), the imperial measurement system gives details on attain-
able distance per volume of fuel, i.e., mile per gallon or mpg consumed. In the
USA, and in the UK in the past (Imperial Unit), the energy intensity of travel was
often expressed in units of BTU per mile, i.e., BTU mi-1. The tables and remarks
in this text systematically contain all units [2].
In the metric system, the amount of exhaust gases can be expressed in g km-1
or oz mi-1 in road transportation, and in g nmi-1 or oz nmi-1 in shipping and in
aviation. The particles can be characterized by the average diameter in mm or in
inches, and the number of the emitted particles without physical units.
1.1 Comparison of Fuel Consumption and Emissions in Transportation 3
Fuel consumption and emissions are measured at the test bench in control
cycles. The consumption quotas from individual cycles are partly different in the
road, ship and airplane technologies and therefore not directly comparable. CO2
emissions can be derived from the fuel consumption.
Table 1.1 presents a comparison of the fuel consumption of different means of
transportation.
Deterioration and wear and tear cause increased fuel consumption and exhaust gas
emissions. Monitoring deterioration is an important way to detect errors in time.
On-Board Diagnosis (OBD) was introduced in vehicle technology as the first
continuous inspection measure in operation [9]. OBD makes it possible to control
exceeding combustion and emission limiting values with sensor signals of com-
bustion and emission relevant elements in vehicles. In principle, the diagnosis, i.e.,
the indirect control of combustion and exhaust gas emission technology has been
applied to airplanes and ships in a very similar way but with other names. It is the
current state of the art in all means of transportation.
Direct control of the chemical composition of burning products with micro
sensors in the combustion chamber and in the exhaust gas system is only partly
state of the art although it could precisely characterize the combustion and the
exhaust gas after treatment process. In the future, if appropriate sensors are suit-
able, a combination of OBD and On-Board Measurement (OBM) technology will
be able to further improve fuel combustion and exhaust gas emission savings [10].
The next stage of direct measurement is the complex use of ‘‘Self Diagnosis’’
(SD) of engines in vehicles, airplanes and ships. SD does not only record when
limit values are exceeded, but also all fuel consumption and emission relevant
phases of operation which characterize the change of operation parameters during
the whole life cycle. Real ‘‘may be wrong’’ fuel consumption and exhaust gas
4 1 Basics of Fuel Consumption and Exhaust Gas Emissions
Table 1.1 Comparison of the fuel consumption of different means of transportation in metric
energy units per tons and kilometers, and in british thermal units per short tons and miles
Means of Local passenger traffic Overland passenger Freight transportation
transportation traffic
Fuel consumption Fuel consumption Fuel consumption
kJ (BTU kJ (BTU kJ (BTU
(t km)-1 (sht mi)-1) (t km)-1 (sht mi)-1) (t km)-1 (sht mi)-1)
Passenger cara 2,595.7 (3,597.6) 2,633.1 (3,619.5) –
Long distance – 811.3 (1,124.5)
busb
Public service bus 1,192.4 (1,652.7) – –
Railway – 757.6 (1,050.0) 386.9 (536.2)
Airplanec – 3,116.8 (4,319.9) 4,503.1 (6,241.3)
Light duty vehicle – – 1,434.1 (1,987.7)
HDV (40 t, – – 1,176.6 (1,630.8)
88.2 lb))
Inland shipd – 865.0 (1,198.9)
Ferry – 1,678.1 (2,325.8)
Fast ferrye 2,366.4 (3,279.8)
Seagoing shipf – – 564.2 (782.0)
a
Mid-sized car with four-stroke self-ignition engine with turbocharger and Common Rail [3]
b
Simple deck with 44 seats and a fuel consumption of 25 l 9 100 km-1 , i.e.,
40.2 l 9 100 mi-1 or 9.4 mpg (US) and 11.3 mpg (UK) [4]
c
Mid-range single aisle airplane with two turbofan engines [5]
d
Small tugboat [6]
e
Water jet propulsion, speed 30–37 knots, SFC 200–212 g (kWh)-1 , i.e., 2.10–2.23 9 10-3
oz BTU-1 [7]
f
Large container ship [8]
emission data can be related to the pre-defined norms, which generally describe the
‘‘may be proper’’ operation, usually measured against the starting phase of the life
cycle. Similar optimal conditions of operation can also be attained after general
inspections and maintenance measures.
Comparison of currently measured data with stored parameters in operation can
lead to the discovery of even smaller deteriorations (see Fig. 1.3).
The preconditions for the Self Diagnosis technology are micro sensors of high
quality and durability, and micro controllers of high storage capacity and high
operation speed.
The European Union Directives 1998/69/EC [11] and 1999/96/EC [12] contained
an important and ground breaking formulation, which stated that monitoring is not
only possible for individual components, but also for the composition of the
1.3 Legislation Frame Conditions 5
The current limitation of the practical use of Self Diagnosis systems is the lack of
selective, durable and precisely functioning sensor systems, and the lack of fitted
micro controller systems for the long time recording and analyzing sensor signals
on-board.
Micro sensors, which can be successfully implemented in air measurement
technology, break down in emission measurement systems, e.g., in the exhaust gas
after treatment system of road vehicles or ships. Figure 1.4 presents some
examples of sensors for air quality monitoring [14].
6 1 Basics of Fuel Consumption and Exhaust Gas Emissions
1 1 1
16 18
2 3 10
14 17
4
13 11
5 12 15
8 13
6 8 8
7 9 9 9
electro chemical cell IR cell photo ionisation cell
Current micro measuring sensors can only limitedly operate in the combustion
chamber and the exhaust gas system of cars, airplanes and ships. One exception is
the electrochemical technique which uses zirconium dioxide technology for the
analysis of oxygen concentration in the exhaust gas.
ambient air
optional
three nozzles
CVS dilution unit air air heater air dryer
filter
mixer
blower
modal
(2)
pressure
(1)
temperature
(6) (3)
load conditions humidity
(4)
wind
(5)
geographical situation
Fig. 1.6 Comparison of operation emissions to test bench emissions with the Artificial Neuronal
Network (ANN)
The key problem of Self Diagnosis is the conversion of real operation emissions to
test bench emissions. In practice, environmental conditions are very variable and
must be related to the nominal conditions at the test bench [15]. A possible
conversion can be obtained through the use of mathematical methods on-board, if
future micro controller technology has very high operation speed and storage
capacity (see Fig. 1.6).
Similarly to the sensor technology, recent on-board micro controller systems
are only partly able to fulfill all of these high quality conditions. Besides hardware
also new, on-board software systems are needed to transfer and compare real data
with stored data [16].
Experiences show that only a few time intervals of real drive, flight, and ship
navigation can be compared with original phases.
1.5 Specific Characteristics of Vehicles’, Airplanes’ and Ships’ Emissions 9
2 500
concentration of unburned
hydrocarbons [ppm]
2 000
high emission level
1 500
1 000
0
0 20 40 60 80 100
time [s]
Fig. 1.7 Unburned raw hydrocarbon concentration in a mid-size car without and with errors
Two European Directives EC 98/69 and EC 99/96 form the basis of intelligent,
direct control of combustion and exhaust gas after treatment technology. Both
Directives contain a passage concerning direct measurement technology in pas-
senger cars and light duty vehicles.
Fuel consumption and exhaust gas emission quotas of several driving cycles are
different and not directly comparable with each other. Existing comparisons
merely operate within average conditions. Direct monitoring opens the way to
direct and quasi continuous measuring fuel consumption and exhaust gas emis-
sions. Self Diagnosis uses the history of changes in engine operation and compares
original data with real data measured in daily traffic.
However, this technology is still under development. The first problem is the
lack of high quality micro sensors. The second problem is the price of sensors.
Recent systems are still too expensive for mass production and too sensitive to raw
conditions in the environment.
Currently, deteriorations are measured at test benches under artificial condi-
tions. Certification prefers artificial measures. Exceeding limiting values can be
tested through changing new and optimally operated elements with artificially
worn and deteriorated elements in the fuel consumption and the related exhaust
gas systems. Both cases ‘‘may be proper’’ and ‘‘may be wrong’’ operations are
measured in driving, flying, or shipping navigation cycles on the test bench. The
fuel consumption and parallel to it, the exhaust gas measuring procedure on the
test bench, have to be repeated multiple times, with both ‘‘new’’ and changed
‘‘old’’ elements. Results are only partially related to the real fuel consumption and
exhaust gas emissions.
Although development has been accelerating in the last years, it is expected that
the evolution of intelligent Self Diagnosis technology will be gradual and slow due
to complex technological problems.
References
In 1900 there were no gas stations—blacksmiths and pharmacists sold the fuel.
People first used petrol for lighting and later to lubricate machine tools. At the end
of the 19th century, boilers in factories and in ships began to use oil instead of coal
[1]. Since this time the consumption of oil, coal and natural gas has been con-
tinuously growing.
Figure 2.1 presents the development of fossil fuel consumption and CO2
emissions [2].
375
18 000
6 000
350
12 000
4 000
325
6 000
2 000
300
0 275
1950 1960 1970 1980 1990 2000 2010
year
World oil consumption Atmospheric concentration of carbon
World coal consumption dioxide
World natural gas consumption Sum of carbon dioxide
emissions from fossil fuel burning
Fig. 2.1 Global consumption of fossil fuels and CO2 emissions per year
BTL kerosene
CLT
fuel ship diesel
sorts oils
GTL LPG
emulsions LNG
alcohols FAME
The different types of fuels have varying physical and chemical properties (see
Table 2.1 [5]).
The different physical and chemical properties lead to changes in containing,
pumping, spraying, and burning characteristics.
Gasoline, diesel, and environmentally friendly vehicle fuels are used in road
transport in the largest quantity.
2.2 Road Transport Fuels 15
2.2.1 Gasoline
Different national and regional norms fix the minimum requirements of gasoline
(term in the USA) or petrol (term in the UK) or Otto fuel (term in other parts of
Europe). In Europe, the requirements are laid out in the norm EN 228 [6].
The main characteristics of gasoline are contained in Table 2.2.
Directives require reference fuels for driving certification in Type approvals (TAs).
Emission limits depending on the fuel type are strictly regulated in all regions of
the world.
The Euro 5 and Euro 6 norms are part of the EU committee overseeing the
implementation (see Table 2.3 [9]).
The American Society for Testing and Materials D439 (ASTM) specifies the
norms for gasoline in the USA [10]. Table 2.4 presents the gasoline reference fuel
in the USA for vehicles with a spark ignition engine.
16 2 Fuels in Transportation
Diesel fuels consist of single hydrocarbon components, which boil between 180
and 370C (356 and 698F). They are produced through the gradual distillation of
crude oil. The refineries also add conversion products, e.g., crack components to
the diesel fuel in increasing volume, which are obtained from heavy oils by
splitting the long molecules [11].
2.2 Road Transport Fuels 17
Similar to gasoline, national norms contain the requirements for diesel oil. In
Europe, the norm EN 590 determines the quality of diesel fuel [12].
The main characteristics of diesel fuel are contained in Table 2.5.
In Sweden and in California, environmental friendly diesel fuels are stipulated
in tax terms in order to reduce pollutant emissions. They are produced at the end of
the distillation process, when the content of aromatic hydrocarbons is reduced and
the sulfur content is largely eliminated [13].
However, the use of these fuels can lead to considerable problems because of
the low lubrication, which is the main reason for wear of the injection valves. In
environmentally friendly diesel fuels, special additives are necessary to avoid
damage.
Diesel reference fuels are used, just as reference gasoline fuels in spark ignition
engines, for the process of the Type approval (TA) of self-ignition engines.
18 2 Fuels in Transportation
Table 2.6 presents the main physical and chemical properties of diesel refer-
ence fuel [14].
Table 2.7 shows the quality of diesel reference fuels in the USA for vehicles
with a self-ignition engine [15].
The most important fuels made from natural gas are Compressed Natural Gas
(CNG) and Liquid Natural Gas (LNG). CNG is predominantly methane. For its use
in motor vehicles, CNG must be dried, compressed to a pressure of 250 bar
(522,136 lbf ft-2), and filled into the motor vehicle’s tank. Internal combustion
engines must be adapted to be able to use CNG [16].
2.2 Road Transport Fuels 19
Table 2.8 Quality criteria of conventional and synthetic fuels in the combustion process
Designation Diesel fuel Synthetic Advantages and disadvantages
from the refinery fuel
Sulfur content 10–5,000 0 Low local SO2 emissions and particles
ppm Easier handling in the exhaust gas
after treatment system
Cetane number 40–55 75–80 Low CO, HC, NO and NO2 emissions
Low noise emission levels and smooth
acceleration
Enhanced technical efficiency in the
engine driving characteristics
Density 0.82–0.86 0.78 Slightly increased consumption
g cm-3 (51.2–53.7) (48.7) on volume basis
((lb ft-3) Less particle emissions
Heating value ca. 43 ca. 44 Slightly smaller consumption on mass basis
MJ kg-1 (BTU lb-1) (18.46 9 103) (18.89 9 103) Fewer CO2 emissions per kilometer
Synthetic fuels can be produced from natural gas with the Gas to Liquid (GTL)
and from coal with the Coal to Liquid (CTL) technology. The final product is
identical in both cases. The convertibility of the products between natural gas and
charcoal is ensured. With the CTL or GTL technologies the base materials are
converted into water–gas (H2 and CO) and later into gasoline and diesel fuel
through the use of catalysts with the help of Fischer-Tropsch synthesis. The
by-products are liquefied gas and liquid paraffin.
Table 2.8 shows the most important differences in the quality criteria between
conventional and synthetic fuels in the combustion process [21].
This technology is mostly used in South Africa. Synthetic fuels are generally
colorless and burn cleanly, have a high Cetane number, and are almost sulfur free [22].
Biogenic fuel, i.e., bio-organic fuel is the name of any plant or animal substances
that can be used in combustion engines. They can support not only the fuel
production, but also aid the market position of agriculture worldwide, since they
increase the income and the employment opportunities of farmers. The aim is to
22 2 Fuels in Transportation
Experiences show that the utilization of 10% of alcohol can lead to small changes
in the spraying, mixing, and burning properties of fuels. The viscosity as a physical
parameter may figure the differences between fossil fuels and alcohols. At 40C
(104F), gasoline kinematic viscosity is 0.88–0.71 cSt, diesel fuel viscosity is
1.30–4.10 cSt, and depending on quality alcohol viscosity is 0.74–1.52 cSt [32].
Micro sensors in the exhaust gas system can discover changes under blended
fuel operation condition in the combustion process over time and can provide
signals for optimal regulation (see Fig. 2.3).
2.2 Road Transport Fuels 23
Table 2.9 Use of synthetic and biogenic fuels in road vehicle engine
Biogenic diesel Poor biogenic oils pressed from plants of the first generation must be treated
by transesterification [26]. The reason for the procedure is to improve the
flowing and burning properties of the resinous raw biogenic oils. The end
product is FAME, which is optimally suitable for application in spark and
diesel engines
Alcohols Biomethanol (CH3OH) and bioethanol (CH3CH2OH) can be used in internal
combustion engines in 100% concentration and in blended fuels in
variable concentrations [27]. Although bioethanol has a higher RON than
fossil fuels, which allows increasing the compression ratio in the
combustion chamber, some experiences show early wear in the
combustion engine
Dimethyl ether Dimethyl ether (C2H6O) is a synthetic product with a high Cetane number
which can be burned in a self ignition engine without soot and with
reduced nitric oxide formation [28]. Due to the low density and the high
oxygen content dimethyl ether has a low heating value. In addition, it
requires customization of the injection equipment because of its gaseous
condition
Emulsions Emulsions of water or alcohols in diesel fuel can be optimally used in self
ignition engines [29]. However, alcohols, primarily methanol, are not or
only badly soluble in diesel fuel. Therefore effective emulgators are
needed to stabilize these mixtures. In addition, measures for anti-
corrosion protection are also necessary. Emulsions reduce soot and nitric
oxide emissions. But application have only been used in a few fleets up
till now. However, a broad testing of different injection systems could
play an increasing role in the future
Fatty acid methyl Fatty acid methyl ester (FAME) can be produced with an alkali-catalyzed
ester reaction between methanol and vegetable or animal fats which are
obtained from oils and greases, e.g., from canola, soya, sunflowers, etc.
[30]. FAME effectively increases the lubrication of fuels and determines
the quality of the combustion process. However, recent FAME is not
economically competitive with mineral oil-based fuels yet because its
production is too expensive
E 10
combustion exhaust
engine system OBM CPU
air HC, CO, NO high capacity
sensors micro
A controller
A-actuators
Fig. 2.3 Measurement of the exhaust gas quality when using blended fuels
24 2 Fuels in Transportation
2.3.1 Kerosene
Kerosene has a leading position as a fuel in civil aviation [33]. It has a boiling
range of 160–250C (320–482F), is thoroughly cleaned and desulfurized, and
consists of 87% carbon and 13% hydrogen. About 5–8% kerosene is generally
produced in the distillation process of mineral oil by cracking. Cracking means the
splitting up of large hydrocarbon molecules into small ones. A concentration of
0.2–0.4% sulfur in the kerosene is allowed. Aromatic mercaptans provide the
typical kerosene smell.
The additive wide cut petroleum ether is available as an alternative jet B fuel
for civil aviation. It has a distillation range of 90–250C (194–482F) and consists
of up to 65% gasoline such as butane gas, pentane, hexane, and up to 35% cracked
kerosene. This composition allows the production of larger quantities at lower
prices. The low ignition point of 20C (68F) gives it the classification of the fire
class Al. Jet fuel B is solely used in the military because its flash point is lower and
it has a lower cold point than Jet fuel A. Civil aviation does not use Jet fuel B for
safety reasons [34].
Fuels for gas turbine jet engines must fulfill a number of demands:
• Low evaporation losses at higher altitudes;
• High boiling point, because of the danger of becoming too viscous in a cold
atmosphere;
• Low viscosity also at low temperatures for optimal spraying;
• No more than 15–20% volatile substances to avoid temperatures in the com-
bustion chamber that are too high;
• High lubrication ability from not too low viscosity to protect fuel valves and
pumps; and
• Near zero concentration of poisonous and corrosive sulfur compounds [35].
Table 2.10 Specifications for fuel to be used in aircraft turbine engines for emission testing
(Appendix 4 of ICAO Annex 16, Volume II)
Properties Unit Value
Density at 15C (59F) kg m3 780–820
Distillation temperature
10% boiling point C 155–201
(F) 311–394
Final boiling point C 235–285
(F) 455–545
Heating value of combustion MJ kg-1 42.86–43.50
(BTU lb-1) (18.42–18.70) 9 103
Aromatics % vol 15–23
Naphthalene % vol 1.0–3.5
Smoke point mm 20–28
(in) 0.79–1.10
Hydrogen % mass 13.4–14.1
Sulfur % mass \0.3
Kinematic viscosity at m2s-1 (2.5–6.5) 9 10-6
–20C (-4F) ft2s-1 (27.22–70.76) 9 10-6
kerosene with certification. One expects full official acceptance of biogenic fuel in
aviation in 2012 and 2013. The relevant admittance standards of introduction are
‘‘D 6751’’ of the ASTMs and ‘‘Defstan 91-91 for Renewable Fuel’’ of the British
Authority [43, 44].
2.3 Aviation Fuels 27
Brazil is planning the introduction of biogenic fuel obtained from sugar cane to
civil aviation based on the successes in the use of alcohols in road vehicle tech-
nology [45].
ISO 8216 and 8217 define the specifications of marine fuels. Marine Distillate
Fuels (MDF) such as Marine Gas Oil (MGO) and Marine Diesel Oil (MDO) are on
average clean fuels [46]. They are liquid at normal temperatures and have a
relatively low density. The fuel can be directly pumped from the storage tank to
the supply tank for one day. From here the fuel flows to a lower mixture tank.
MDO and MGO fuels are usually used when the vessel is maneuvering [47].
Heavy Fuel Oil (HFO) is the residual part of distillation with a relatively high
density. It must be stored in the bunker tank and preheated for pumping to the
settling tank. HFO is made suitable for use in marine diesel engines through the
addition of certain flammable substances [48].
The physical and chemical properties, such as the viscosity and the density, and
the field of application of the Intermediate Fuel Oil (IFO) are between MDF and
HFO.
Marine Distillate Fuels are mixtures of different middle distillates from petroleum
refining for marine diesel engines which have four qualities for seagoing ships
[49]:
• DMX is a very light gasoil with an excellent cold quality, characterized by the
Cloud Point. It is used almost only as an emergency fuel;
• DMA can also be used as a navy gasoil or Marine Gas Oil (MGO). It is a gasoil
of medium density;
• DMB can be used as a navy diesel oil or a Marine Diesel Oil (MDO). It is a
relatively heavy gasoil with parts of vacuum gasoil; and
• DMC is a fuel consisting of heavy gasoil. Delay oils can also partly be mixed to
DMC.
Table 2.13 presents the main parameters of MDF [50].
28 2 Fuels in Transportation
HFO is the residual part of the distillation and cracking plants in petroleum
refining. The international trade name is Residual Marine Fuel RME, RMG, or
RMK.
The parameters of HFO are presented in Table 2.14 [51].
The main ingredients of HFO are alkenes, cycloalkenes, and highly condensed
aromatic hydrocarbons, such as asphaltene with about 20–70 carbon atoms per
molecule and a boiling range between 300 and 700C (572 and 1,292F).
Heterocyclic nitrogen with a nitrogen content of 0.5% by weight and sulfur sub-
stances with a sulfur content of 6% by weight and metallic pollutants obtained
from oil such as nickel, vanadium, sodium, calcium, and others are concentrated in
HFO [52].
The use of HFO is regulated in MARPOL 73/78 Convention, Annex VI, which
defines the emissions of sulfur combustion products in certain areas of the ocean.
The regulation is important for the environment, because most seagoing ships use
HFO for the main engine on the high see with higher sulfur content than permitted
in some individual areas. Ships have to switch to environmentally friendly fuels in
protected areas [53].
Heavy Cycle Oil or slurry fuel can be contaminated with ‘‘catalyst fines’’
when a crushed zeolitic catalyst is used. Micro particles of slurry are often
responsible for abrasion in the fuel system and engine. Fines can be eliminated
in a separator system or in similar special devices in the processing phase of oil
production [54].
2.5 Summary and Recommendations: Fuels in Transportation 29
More than 95% of the fuels used in transportation are fossil fuels, despite fast
growing prices. The aim is to decrease the proportion of fossil fuels in ship navi-
gation to 80% worldwide by 2020.
Fossil fuel consumption can be significantly reduced through the use of pure
biogenic fuels of the first generation, like biologically produced diesel and FAME,
but the substitution would require substantially higher costs than consuming
conventional fuels. Second-generation biogenic fuels such as alcohols promise to
be cheaper but are still under development and used only in few countries like
Brazil. The third generation uses gasification of organic wastes and synthesis by
the Fischer-Tropsch reaction and can be produced more economically than the first
two generations. In the long term, the most economic solution is the production of
BTL from waste biomass or algae.
Synthetic fuels are produced from coal and natural gas. South Africa (CTL) and
Qatar (GTL) are the most important producers [55].
About 90% of fuels are consumed in road transport, only approximately 10% are
consumed in other sectors of transportation. From this first amount, about 65% of
the total fuel consumption in road transportation is used in passenger car
transportation. The EU Commission has the aim of increasing the proportion of
biogenic fuels in transportation to 20% by 2020 [56].
The use of biogenic and synthetic fuels is only in the growing phase at present,
but they have to gain a higher proportion in the future fuel supply. Great interest is
expected in all regions of the world.
Synthetic fuels are produced from coal and natural gas with the Fischer-
Tropsch synthesis. Biogenic and synthetic fuels require the same infrastructure and
30 2 Fuels in Transportation
the same engines as commercial petrol and diesel fuels. The combination of
individual fuels is possible.
CNG is only a small portion of the fuel used in road transport and its share is
growing very slowly. The use of LNG and hydrogen in road transportation as fuel
is not yet sure.
The most important fuel in civil aviation is kerosene. The use of synthetic and
biogenic fuels in experimental airplanes is only a small portion of the complete
structure. Widespread substitution of kerosene with both new types of fuel is not
expected in the near future.
The industry aims to develop and to produce several fuel types as uniformly as
possible and to make it easy to switch between fossil and synthetic or biogenic
fuels. Theoretically, the first step of adding 50% biogenic and synthetic fuel can be
increased to 100%, because chemical additives make alternative fuels very similar
to classic kerosene. However, the introduction of alternative fuels will take a long
time to happen.
The combustion of hydrogen results in 2.6 times more water vapor than the
combustion of jet fuel and would completely eliminate CO2 emissions in aviation.
Beside technological diffculties, a disadvantageous aspect is that the utilization of
hydrogen requires a new system of logistics, storage, and handling for all aircraft
and ground equipment.
The most common fuels in ships are MDF and Heavy Fuel Oils. These are con-
ventional fuels and available at a low cost worldwide. Marine diesel engines could
theoretically use a broad range of synthetic and biogenic fuels and their mixtures,
i.e., flended fuels if engines and containers of the ships were modified.
The application of synthetic and biogenic fuels is not permitted in shipping since
their energy content is too low to guarantee the average needed distances at sea,
except special sea-going and inland ships. Moreover, the costs of first- and second-
generation biogenic fuels are much higher than the cost of fossil marine fuels. It is
expected that the next generations of biogenic fuel will achieve more advantages in
marine transport. Despite all positive developing results, the introduction of bio-
logic and synthetic fuels in ships will happen slowly and will be evolutionary.
LNG is used in LNG carrying tankers, and hydrogen in the fuel cells of
submarines. The proportion of non-fossil fuels used in the ship transportation is
very small. The first broad ranged applications are expected in ferries, inland ships,
and special purpose vessels.
2.5 Summary and Recommendations: Fuels in Transportation 31
GTL may be a fuel of the near future, if the consumption of demanded energy
in the production process can be decreased. Biogas and biogenic fuels are already
used in road transportation worldwide. In the shipping they can be introduced in
city-ferry routes at first, and then later on short sea routes.
References
The first vehicles were powered by steam engines in the eighteenth and nineteenth
centuries, and were followed by gasoline and diesel fuel-powered internal com-
bustion engines from the beginning of the twentieth century. The first efforts to
save fuel came after the Second World War, but the serious saving of fuel began
after the first oil crisis in 1973 [1]. Since then, manufacturers have been developing
vehicles that are more and more fuel efficient.
According to the definition of ISO 3833:1977, a motor vehicle is a self-pro-
pelled, wheeled transportation mean for operation on roads [2]. Nowadays, there
are more than 1 billion road vehicles, including station wagons, and light and
heavy duty trucks in the world. More than half of them are cars, but the proportion
of commercial vehicles, particularly of heavy duty vehicles (HDVs), is rapidly
rising. The USA had the first largest and China had the second largest fleet of
motor vehicles with 239.8 and 78 million pieces in 2010 [3].
The amount of fuel used in several countries of the world is quite uneven and
depends on the number, the age and the technical quality of vehicles, the average
distances traveled, the cost of fuel, and the personal incomes of people. The
body
trunk engine
chassis
exhaust gas after
wheel and tire treatment
number of inhabitants related to the number of cars and the Gross Domestic
Product (GDP) nearly has an inverse relationship [4].
The ratios range from 234 people per car in the Far East to 1.6 people per car in
highly developed countries such as those in the EU, Australia, and the USA. The
distribution of commercial vehicles is more balanced than the density of cars on
the world because supplying people with goods means an important task in all
countries. The scope ranges from 55 people per commercial vehicle in Africa to
2.6 citizens per commercial vehicle in the EU, Australia, and Oceania [5].
By 2015, the number of road vehicles will increase to 1.124 billion. Currently
fuel consumption is intensively growing in all sectors of road transport. Recent
distribution is rapidly changing because of increasing meaning of developing
countries. In the next years, Europe will have a portion of 33%, North America
33%, Asia 25%, and other regions 9% [6].
Automobile body styles are highly variable but the main construction principles
are common. The main structural elements of passenger car construction are
shown in Fig. 3.1.
The long history of automobile technology has led to a wide spectrum of vehicle
types (see Table 3.1) [7].
Depending on use and construction, the EU legislation classifies street vehicles
with their own engines according to Directive 71/320/EEC in two classes (see
Table 3.2) [8].
3.1 Road Vehicles
According to the European classification, cars and light duty vehicles (LDVs)
with GVWR under 3.5 t belong to the classes M and N1, mid-size vehicles with
GVWR from 3.5 to 12 t belong to the class N2, and HDVs with GVWR over 12 t
belong to the class N3.
The EPA classification has four main groups (see Table 3.3) [9].
In Japan, light cars ‘‘Keijidosha’’ are less than 3.4 m (11.2 ft) long, 1.48 m
(4.9 ft) wide, and 2.0 m (6.6 ft) high. The engine has a cubic capacity of less than
660 cm3, i.e., 40 cu in. Compact size vehicles commonly called ‘‘5 number’’
vehicles are up to 4.7 m (15.4 ft) long, 1.7 m (5.6 ft) wide, and 2.0 m (6.6 ft) high.
The engine’s cubic capacity is up to 2,000 cm3, i.e., 122 cu in [10].
There are considerable differences in construction and operation among types of cars.
Average low powered cars provide an engine cubic capacity from of 1.2–1.6 l, i.e.,
75–100 cu in DI technology and operate with three or four cylinders. High-powered
3.1 Road Vehicles
Table 3.4 Distance per hour, performance of engine, energy consumption per hour, and acceleration depending on car class
Class of car Distance Performance Energy consumptionc Accelerationb
km kW (s)
kWh MJ (BTU)
(mi) (HP)
Low power 140–170 30–40 12–20 43–72 40,973–68,243 15
(87–106) (40–54)
Middle class 170–200 147–221 20–30 72–108 68,243–102,364 12
(106–124) (197–297)
Upper and SUVa over 200 240–250 30–32 108–115 102,364–136,485 9
(over 124) (322–336)
a
Sport utility vehicle
b
From 0 to 100 km h-1 , i.e., from 0 to 62 mph
c
Converted to 100 km
37
38 3 Construction of Transportation Means
Table 3.5 CO2 emissions and fuel consumption of average European cars
Class of car CO2 emissions Diesel fuel mpg US mpg UK
g km-1 consumption
l (100 km)-1
Low power 100–130 3.46–4.50 68.03–52.31 81.64–62.78
Middle class 130–180 4.50–6.23 52.31–37.78 62.78–45.34
Upper and SUVa 180–270 6.23–9.35 37.78–25.15 45.34–30.21
Land rovers 270–390 9.35–13.59 25.15–17.31 30.21–20.79
a
SUV sport utility vehicle
upper class cars have an engine cubic capacity of 5.0–5.5 l, i.e., 312.5–343.7 cu in,
and contain a 10 or 12 cylinder engine.
Fuel consumption parameters depend on the main construction parameters (see
Table 3.4) [11].
Table 3.5 shows the average CO2 emissions and fuel consumption measured
according to the New European Driving Cycle [12].
Best results (3.4 l (100 km)-1, i.e., 69.2 mpg (US) and 83.08 mpg (UK)) can be
achieved with internal combustion engines in low-powered cars, using a turbo-
charged, three cylinder 30 kW (41 HP) self ignition engine [13].
A middle class car powered by natural gas uses 4.0–5.0 kg (8.8–11.0 lb) of
natural gas per 100 km (62.15 mi) and emits 100–140 g of CO2 per km (5.68–
7.95 oz mi-1). Natural gas-powered cars emit 20% less CO2 than cars with fossil
fuel combustion in the engine [14].
Light duty vehicles are on average 7–8 m (22.95–26.23 ft) long, 2.5–3.0 m (8.20–
9.84 ft) high, 2.0–2.5 m (6.56–8.20 ft) wide, have a GVWR of 5.0–5.5 t (11,023–
12,128 lb) and can carry 13–15 m3 (9.95–11.47 yd3, i.e., 458.9–529.5 ft3) of
freight [15].
The fuel combustion and exhaust gas emissions of LDVs are between cars and
HDVs.
The cold start at temperature of 20C (68F) should not last longer than 15 s.
Electrically heated radiators or burners can lead to lower fuel consumption and
emission especially in very cold weather [16].
In Europe, modern LDVs have to meet the requirements of the exhaust gas
norm Euro 5 and they will have to meet the Euro 6 norm in 2014. These directives
require special exhaust gas after treatment systems. The passive filter system
consists of a filter and a catalyst module without electronics and an engine control
system. It removes about 70% of particles. Active filter systems are always con-
nected to the Engine Control Unit to be regenerated as required by the cleaning
process. The filtering rate in active filter is better than in passive filters; however,
3.1 Road Vehicles 39
the costs of the highly complex system are much higher than in the more simple
passive fitter systems.
Regular maintenance of LDVs is necessary after 90,000–100,000 km (55,890–
62,100 mi). Guarantee intervals for engines in Europe are limited to 200,000 km
(124,200 mi) or 2 years, depending on which limit is reached first [17].
In Europe, Heavy Duty Vehicles (HDVs) have a GVWR over 12,000 kg. They
usually use a six cylinder self-ignition in-line engine with four valves per cylinder, a
Common-Rail direct injection system, a turbocharger and an Exhaust Gas Recir-
culation also often known as an Exhaust Gas Refeeding system. The cubic capacity is
on average between 12,000
and 13,000 cm3 (0.42–0.46 ft3) and the maximum performance is 330–360 kW
(448–489 HP or 313–342 BTUs-1) in the range of 1,000–1,300 rpm [18].
The wheel distance amounts to 4.5–4.8 m (14.75–15.79 ft), the unloaded
weight to 12,000–12,500 kg (26,460–27,563 lb) and the GVWR to 25,000–
28,000 kg (55,125–61,740 lb). The tank volume contains about 600 l (21.20 ft3).
The fuel consumption is between 30.0 l (100 km)-1 (7.84 mpg (US), i.e., 9.41
mpg (UK)) and 32.0 l (100 km)-1 (7.35 mpg (US), i.e., 8.83 mpg (UK)) [19].
The power transmission is carried out with an automated 12 gear but newest
models contain a manual transmission up to 16 gears with a transmission factor of
4.0–5.0. The cubicle is usually equipped with four seats. Braking is carried out
using disc brakes [20].
40 3 Construction of Transportation Means
landing gear
wing and
connecting parts
Flying
apparatus
Lighter Heavier
than air than air
In safety technology, the first important task is to prevent accidents; the second
is to lower the number of injuries from accidents by using active and passive safety
technology; see Fig. 3.2.
Designed for passive safety, modern cars use not only lightweight materials, but
also new vehicle geometries and components that can act as energy-absorbing
crumple zones. Modern light cars achieve the performance of a conventionally
designed heavy vehicle. More over, they usually provide a larger and highly safed
space for crashes [25].
3.2 Airplanes
Aviation began to develop about 120 years ago with the first winged airplanes
which were powered by four stroke engines. Fuel consumption at this pioneering
time did not play a decisive role. Development was fast and more than 2,100
airports were already in existence in the USA in 1932. In the decades after the
Second World War, light weight materials, jet engines, and computer technology
began to have more and more of an effect on the development of aircraft con-
struction [26].
Currently, general aviation is defined as all aviation other than scheduled
commercial and military aviation.
In 2010, there were 320,000 active general aviation aircrafts and helicopters
worldwide, including 17,770 passengers and 89,129 military airplanes, and 26,500
civil and 29,700 military helicopters.
In addition to this number, there were also 4,000 private jets, according to the
statistics of General Aviation Manufacturers Association (GAMA) [27].
The number of airplanes in the world has increased rapidly over the last dec-
ades. Worldwide general aviation billings rose by 1.2% to US $19.7 billion due to
large-cabin, long-range aircraft.
About 6,000 Instrument Flight Rules flights are in the air at peak travel times.
42
km h-1 m km m m kN
(nmi h-1)d (ft) (nmi) (ft) (ft) (lbf)
Small turbopropa 72 667 7,620 2,522 32.84 28.42 PW150A 165
(360) (24,984) (1,362) (107.7) (93.18) (37,095)
Single aisleb 160 750–850 12,000 4,500 39.5 34.3 CPM56-7B26 336
(405–459) (39,344) (2,430) (129.5) (112.5) (75,539)
Twin aislec Over 500 995 13,115 15,200 73.0 79.8 Trent 900 313
(537) (43,000) (8,207) (239.5) (261.6) (70,368)
Military transportere 100–150f 620–630 3,000 25–30 35–40 3,500 kW/engine
(335–340g) (1,619)h (82.0–98.4 ft) (114.8–131.1)i (4,698 HP/engine)
Military tankerj 2,000
(1,080)k
a
Bombardier Q-400 [37]
b
Boeing B737-800 [37]
c
A380-800 [35]
d
Speed in nautical miles per hour or abbreviated as KTS knots per hour
e
C-130J: Above 15 m (49.3 ft) obstacle the takeoff distance is 1,400–1,500 m (4,590–4,918 ft), and the landing distance is 700–800 m (2,295–2,623 ft) [38]
f
Soldiers or paratroopers, 3–10 system operators, 1–2 loading foreman [38]
g
The maximum speed is 670–680 km h-1 , i.e., 362–368 nmi h-1 [38]
h
Special transporters reach the maximum distance of 6,500 km (3,510 nmi) [38]
i
The wing area is 150–160 m2 , i.e., 1,613–1,720 ft2 [38]
j
A330-200: Mass of transported fuel to other airlines is 65 t (143,172 lb) [39]
k
Maximum cruising time is 2 h [39]
43
44 3 Construction of Transportation Means
6.5
[1*(passenger*100 km) ]
-1
fuel consumption 6.0
5.5
5.0
4.5
4.0
1990 1992 1994 1996 1998 2000 2002 2004 2006
year
aluminum-lithium
titanium
composites
standard materials
composites
standard materials
The main groups of structural elements of an airplane are presented in Fig. 3.3
[28].
Airplane systems have become very complex (see Fig. 3.4) [29]. However, this
book deals only with rigid wing airplanes (see Table 3.6) [30].
plastics
advantages disadvantages
- negative climate balance by the
- small thickness production
- small specific weight - difficult abolishment at recycling
- application of new joining - high cost of production
techniques, like gluting - no protection against lightning in
- high quality of chemical and the vehicle body, airplane fuselage
thermal resistance and ship hull (no Faraday cage)
- improved physical properties - ductile and lack of flexibility
Small airliners usually offer optimal fuel saving economy. In this type of airplanes
the fuselage is very narrow. There are from two to four seats in a row. The cabin
provides seals for 10 and 80 passengers. The cruising altitude is 7,000–8,000 m
(22,951–26,230 ft), and the range is up to 1,500 km (810 nmi) [32].
Airplanes with modern turboprop engines have the lowest Specific Fuel Con-
sumption (SFC). In the future, contra rotating rotors can further improve SFC.
However, there are two main problems for a wide ranged application of small
turboprop airplanes:
• They are flying at low altitudes and useing very congested air spaces; and
• The noise emission level of turboprop engines is high, especially that of contra
rotating propellers.
Improving these features and fulfilling requirements needs further intensive
development in the near future.
Narrow body or single aisle airplanes usually fly middle distances at altitudes of
12,000 m (39,344 ft). They have a maximum of six seats in the cabin in a row.
New narrow body airplanes using turboprop engines with contra rotating
46 3 Construction of Transportation Means
Table 3.8 Development of the international maritime fleet from 2005 to 2009 in 106 DWT
Ships Years
2005 2006 2007 2008 2009
Tankers 368.4 387.7 411.0 439.3 463.3
Bulk goods 319.2 341.7 363.6 386.6 414.4
Container ships 99.2 1,117.7 128.2 144.6 161.9
General cargo 95.3 97.4 100.6 102.8 106.8
Passenger ships 5.9 5.9 6.1 6.2 6.4
Total 888.0 944.4 1009.55 1,079.55 1,152.8
propellers provide very low SFC. However, the field of civil application is cur-
rently limited narrow body airplanes do not use long distances. Through new
innovations, this situation could be changed in the future [33].
Wide body airplanes normally have a cabin with a large diameter, provide twin
aisles, use turbofan engines, and fly middle or long distances. They are more fuel
efficient than narrow body single aisle airplanes with the same or similar turbofan
engines but do not reach the particularly low SFC of turboprop engine-driven
small airplanes with contra rotating propellers which have an extremely high
efficiency [34].
The newest and largest passenger airplanes (A380 and B787) use a very high
portion of glass fiber strengthened composite substances and sandwich construc-
tion to reduce the weight [35, 36] Optimal aerodynamics, efficient main and
auxiliary engines, and modern electronic technology in Very Large Airplanes
(VLAs) save fuel and operating costs by up to 10–15% in comparison to mid-size
airplanes. In addition to the basic models, new freight and long-range types with a
shorter fuselage are in development.
Table 3.7 shows examples of recent airplane types.
12
crude oil
10
oil products
world trade by
shipping [10 t]
8 iron ore
9
coal
6
grain
4 other goods
complete
2
0
2000 2002 2004 2006 2008 2010
year
stern smokestack or
funnel
superstructure
anchor
deck
Fuel makes up a high proportion (near 50%) of the takeoff mass of airplanes. The
B767-200/200ER, a modern long-range, wide body, twin aisle airplane has the
maximum takeoff weight of 179,170 kg (395,070 lb), the empty weight of
86,000 kg (189,630 lb), and the maximum freight load of 30,000 kg (66,150 lb).
Tanks contain approximately 73,000 kg (160,965 lb) of fuel which allows for
flight time of 15–16 h, i.e., 12,500–13,333 km (6,749–7,199 nmi). Safety regu-
lations require additional fuel of 7,000 kg (15,435 kg) to make it possible to fly an
extra time of 1.5 h. This equals to the distance of 1,200–1,300 km (648–702 nmi)
or the weight of 70–75 passengers [42].
Aluminum has been the first new material used in construction and its application
resulted in lower weight and decreased operational and maintenance costs by 50%.
Table 3.9 Field of use, propulsion system, and type and construction material of ships
48
In modern airplanes, the tail segments, the fuselage, the wing and the wing
stabilizers, the skin, the spoilers, the leading and the trailing edge flaps, the engine
inlet, and the aerodynamic cones are made of composite materials (see Fig. 3.6).
Interior cabin furnishings and passive interior noise treatment, e.g., wall insu-
lation for cabin noise may be reduced in the future if active noise control tech-
nology is developed. However, passive noise controls, i.e., insulation blankets are
normally not only used for noise reduction, but also for heat insulation. Reducing
insulation would require more power for heating and cooling [44].
The newest airliners’ major structural elements are completely made from
Kevlar and CFC materials. Certification of this technology has been completed
[45].
The disadvantages of most plastic materials are their higher rigidity and the
lower conductivity. Many plastics are still too ductile to be used as airfoils as they
tend to break under constant load; see Fig. 3.7.
Military aviation started to use Carbon Fiber Reinforced Plastic (CFRC)
materials approximately 20 years earlier than civil aviation [46]. Since that time,
glass fiber strengthened composite materials have been increasingly used not only
in civilian airplanes but also in military airplanes and helicopters. Even modern
fighters which are subject to enormous loads in flight, use more plastic compo-
nents. As experience has shown, the loading gate of future military airplanes can
be completely manufactured from CFRC.
The age of industrial shipbuilding began in the middle of the nineteenth century
with steam ships which continued to be built until the first oil crisis in 1973. The
propulsion system contained the coal bunker, the steam engine, and later the oil-
fired boilers and steam turbines. In recent decades, marine engine technology has
been continuously changing [47]. In the last 10 years, maritime shipping has
rapidly developed, compared to the previous centuries or millennia.
Today, there are more than 43,349 civilian ships over 1,000 GRT. Panama
(6,124), Liberia (2,162), and China (1,822) lead the rankings. Besides cargo and
passenger ships approximately 4 million fishing vessels are also consuming fuel
and emitting exhaust gas pollutants and GHG gases [48].
In 2009, the international merchant fleet consisted of 40% tankers, 36% bulk
carriers, 14% container ships, and 9% other ships; see Table 3.8 [49].
The quantity of freight transported by ships is intensively increasing. In 2010,
the shipping industry transported over 10,000 million tons of cargo, equivalent to a
total volume of world trade by sea of over 42,000 billion ton-miles; see Fig. 3.8
[50].
Total cargo has increased by 8% over the previous years. Today, shipping
contributes between 1 and 5% to the international GDP [51].
52 3 Construction of Transportation Means
The average age of the international fleet, including ferry boats and special
ships is 18.6 years. The oldest types of ships are reefers and passenger ships with
an average age of more than 25 years. Container ships and tankers are the newest
types of ships on the sea [52].
There is a very variable selection system of seagoing and inland ships of vessels
and passenger ships. One aspect of distingation in the construction. A further
criterion is the application in civil and in military service. In this context sub-
marines mean a specific class.
The main characteristic parameters of ships are contained in Table 3.10.
Merchant vessels are becoming ever larger to adjust to the load requirements and
to decreased fuel consumption. Table 3.11 shows the main operation parameters of
several types of vessels [63].
The Queen Mary 2, one of the largest ships of the world, has an engine which
performs at 4 9 21.5 MW, i.e., 86 MW (two fixed and two azimuthing), i.e.,
115,436 HP. The installed board power reaches 126.7 MW (170,067 HP) which is
3.4 Construction of Ships 53
higher than the engine power. At an average speed of 30 kn, i.e., 56 km h-1, the
fuel consumption is 252 t d-1, i.e., 555,066 lb d-1 at an average speed of 30 kn,
i.e., 56 km h-1. It equals to 40–45 ft per 1 gal (UK), i.e., 12.2–13.73 m per
4.546 l of navy oil or 6.6–6.0 9 10-3 nmi gal-1 (UK) or 7.9–7.2 9 10-3
nmi gal-1 (US).
Container ships intensively vary in size, construction, and power. The largest
containers ships have an 8–14 cylinder engine. Container transport must be fast,
because goods in the containers have to be delivered to the customers as soon as
possible. The SFC is between 163 and 170 g kWh-1 (1.68 9 10-3–1.75 9
10-3 oz BTU-1) in a speed range from 25.2 to 27.5 kn maximum, i.e., from 46.7
to 51 km h-1 [70].
The fuel consumption of container ships is approximately half of that of pas-
senger ships in the same category. The largest ships such as tankers with no
perishable goods have the lowest level of fuel consumption. They can optimize
speed and operation. Comparisons consider a fuel oil viscosity of 730 cSt at a
temperature of 50C (122F), according to Fuel Standard ISO 8217.
Modern merchant vessels achieve 120 g kWh-1, i.e., 1.263 9 10-3 oz BTU-1
which is the lowest level in the transportation sector with internal combustion
engines. The interval is wide ranged. In shipping, the highest SFC is provided by fast
ferry and specific navy boats with hydrofoil, jetfoil, hovercraft, fast monohull, and
catamaran technology which have a SFC above 220–250 g kWh-1, i.e., 2.317 9
10-3–2.632 9 10-3 oz BTU-1. The consumption rates are related to the rpm [71].
Double bottom technology has been introduced in container ships first, later in
bulk carriers, tankers, and then in other ships. For this type of construction is the
reduction of corrosion, material fatigue, crack formation, overloads, and damage
especially important [72]. However, double bottom technology contributes to
higher manufacturing and operating costs and higher SFC.
The fastest ships are catamarans because of the very low hydrodynamic resistance.
Fast mono hull designs cannot achieve the same maximum speed, but they are
more economical and can be used for all kinds of fast ships, such as fast passenger
ships, ferries, container ships, refrigeration, and Ro–Ro ships.
The optimal streamlined form and the specific smooth surface of the hull reduce
the resistance of waves below the waterline. Above the waterline the construction
increases the crossways stability and the usable space. Ever larger hulls are being
constructed with reduced specific weight through the use of high-strength ship-
building steel instead of normal quality steel. Furthermore, in fast construction, the
stern is optimized for the propeller to work at high speed.
In the shipping fast catamaran and mono hull constructions consume the highest
specific rate of fuel and emit the highest specific volume of exhaust gas pollutants
[73].
Ships for the North Atlantic are expected to be in service for 25 years. Therefore,
hull scantlings and steel distribution must be constructed in accordance with the
Common Structural Rules (CSR) [74]. CSR does not require a radical change from
the existing rules, but it raises specific issues concerning structural strength, cor-
rosion, watertight integrity, and fatigue.
The CSR multi-purpose software supports the design and analysis of hull
structures and the cross-section of vessels. The main aim is to minimize the
additional amount of steel required. Computer software determines the scantlings
of all structural components automatically based on requirements for the vessel’s
size, shape, weight, class, cargo load, and fuel consumption.
3.5 Summary and Recommendations: Construction Technology 55
3.5.2 Airplanes
The main structural elements of an airplane are the fuselage, the wings, the tail
unit, and the landing gear. Planned range, payload, speed, and altitude are decisive
for the construction.
The trend has continued toward larger and more comfortable airplanes in the
last decades. Their dimensions and weights are increasing despite the use of lighter
CFC materials. In the same time interval, parallel to it, new constructions lead to
lower SFC and decreased specific operational costs.
56 3 Construction of Transportation Means
3.5.3 Ships
References
1. Eckermann E (2002) Vom Dampfwagen zum Auto. Delius Klasing Verlag 1st Edition. ISBN:
3-7688-1339-8
2. ISO 3833: Road vehicles—Types-terms and definitions. http://www.iso.org/iso/
catalogue_detail.htm?csnumber=9389
3. Motor vehicle. http://en.wikipedia.org/wiki/Motor_vehicle
4. Vehicle Miles Traveled (VMT), Gas Prices, and GDP Analysis, March 2011. http://
www.scribd.com/doc/51841381/Vehicle-Miles-Traveled-VMT-Gas-Prices-and-GDP-
Analysis-March-2011
References 57
The fuel economy of SFC of the engine is usually measured on the test bench
under nominal conditions and represented in a consumption identification diagram.
The real fuel consumption in travelling, flying and shipping normally differs from
the consumption on the test bench. Road vehicles’, airplanes’, and ships’ real fuel
consumption depends on the performance, load, speed, and operation conditions at
first.
The Type Approval (TA) of the road vehicle’s, ship’s, or airplane’s engine has
been developed for examinations at the test bench with defined test cycles. The
analyzers are usually large devices certified by national authorities.
The direct method is the measurement of fuel consumption. The indirect
method is the analysis of carbon emissions and then mathematically calculating
the fuel consumption on the basis of the CO2 balance [1].
Currently, fuel consumption is monitored by small sensors with a quick
response time. Their basic principles are conductivity, capacitivity, ultrasound
technology, and radiometry. Figure 4.1 shows the different variants of fluid flow
measurement [2].
Depleting the tanks is to be strictly avoided in all types of vehicles, aircrafts,
and ships. The amount of fuel in a tank is usually measured by static pressure or
capacitive sensors at the bottom of the tank and by a floating switch at the surface
of the fuel. Few methods continuously estimate the fuel flow in the fuel pipe
between the tank and the engine. Combinations of static and dynamic control
methods are useful for safety reasons.
Fuel management systems record fuel consumption, fuel transfer, and refilling
of tanks. Fuel management considers the daily consumption of the entire fleet,
down to individual fuel tanks and maintains a complete history of all events,
providing reports for billing purposes and integrating timely fuel inventory.
Fleet wide fuel purchase, fuel consumption, and, in the future, emissions, i.e., the
complete financial system can be continuously controlled by using the Internet [3].
impeller
The fuel tank is the central element of the supply system. It is made of surface
treated steel or plastics according to the space requirements in vehicles, airplanes,
and ships [4].
In road vehicles, the fuel system consists of a filter, a small reserve tank as a
fuel reservoir for use when the vehicle is not level on a curve, an electric diving
pump, a fuel level, a pressure, and in special cases a flow sensor as well as
electrical and hydraulic connections; see Fig. 4.2.
The fuel is pumped from the fuel tank into a pressure regulator, which keeps the
pressure of the fuel constant, and forced through a fuel filter, a mass control valve,
which controls the mass flow independent from the fuel level in the tank and at the
end of the supply chain to the CR system with a regulator and control sensor.
When electronic fuel injection was first introduced, the electric fuel pump was
always outside the tank. In new vehicles it is more common to have the fuel pump
installed within the tank. Fuel pumps must supply the engine with sufficient fuel
under all operating conditions with the pressure necessary for injection. The
essential requirements of pumps are:
4.1 Fuel System in Vehicles 61
00000000
fuel filter
93/116/EC applies to the carbon dioxide emission and the fuel consumption of all
motor vehicles of the category M1. The weight of fuel consumed is calculated
according to the carbon balance method using the measured emissions of CO2 and
other carbon-related emissions (CO and HC):
Mgasoline ¼ f ðCO2 ; CO; HC Þ ð4:1Þ
The CO2 emissions are measured during the test cycle simulating both urban and
highway driving patterns as described in 91/441/EEC (1), Appendix 1 of Annex
III. Test results are averaged and expressed in Europe in g km-1 or g mi-1 [10].
Similar to the EU method, in the USA the measured fuel is based on the
regulation 40 CFR Part 600-113 [11]. Fuel consumption is determined on test
benches according to the carbon balance method from the CO2, CO, and HC
emissions analyzed in miles gal-1 (US) in US EPA II and in Highway Fuel
Economy Cycle (HWFET) [12, 13]. In Europe, the fuel consumption is expressed
in l km-1 or l (100 km)-1, in the USA in gal mi-1 or in the most cases, in mpg.
Japan uses synthetic cycles, such as the 11 Mode cold and 10 ? 15 Mode hot
cycle, respectively, New Driving Cycle JC 08, which is similar to the NEDC;
however, they apply different speeds and gears [14].
The relation between the fuel consumption and the speed of an average mid-
sized car in the NEDC is presented in Fig. 4.3 [15].
According to the statistics, the average fuel consumption of a European mid-class
car is 6.2 l (100 km)-1, i.e., 47.6 mpg (US) and 45.5 mpg (UK). The cold start phase
in the first 120–180 s demands an extraordinary large amount of fuel, above 30 l
(100 km)-1 i.e., 105 mpg (US) and 126 mpg (UK). The urban fuel consumption in the
second phase is 8.2 l (100 km)-1, i.e., 28.7 mpg (US) and 34.4 mpg (UK) and the
highway fuel consumption in the last phase is 5.1 l (100 km)-1, i.e., 46.1 mpg (US)
and 55.3 mpg (UK).
4.1 Fuel System in Vehicles 63
fuel consumption
part one
200 20
[l*(100 km)-1]
speed [km*h-1]
120 12
6.
80 5. 5. 10
4. 4.
3. 3.
40 2. 4
2. 2.
1. 1. 1.
0 0
0 200 400 600 800 1000
Fig. 4.3 Fuel consumption of an average European car relative to time of NEDC
Since trucks and buses are too heavy and too large, not the entire vehicle’s but the
engine’s emissions are controlled at an engine test bench with computer-supported
driving cycle programs [16].
In Europe, the emissions of heavy-duty vehicles are examined using Directive
70/220/EEC including amendments and corrections. The European Stationary
Cycle ESC is a steady-state procedure with a 13-point examination. The European
Load Response Cycle ELR has the purpose of opacity determination. In the
European Transient Cycle ETC, different driving conditions are represented by
three parts, including urban (maximum speed is 50 km h-1 (31.05 mi h-1), with
frequent starts, stops and idlings), rural (step acceleration segment, average speed
is 72 km h-1) (44.7 mi h-1), and motorway driving (average speed is 88 km h-1)
(54.65 mi h-1). The duration of the entire cycle is 1,800 s. Each part lasts for
600 s [17].
However, with specific and large test dynamometers, which sometimes have
artificial cooling, pressurization, and air humidification, heavy duty trucks and
buses can be dynamically controlled for research and development experiments;
see Fig. 4.4 [18].
In the USA, the EPA Urban Dynamometer Driving Schedule (UDDS or Cycle D)
has been developed for chassis dynamometer testing of heavy-duty vehicles. The
64 4 Fuel System and Fuel Measurement
NOX
CO
CO
air filter HC
jet outlet
dilution pressure
HD-UDDS cycle should not be confused with the FTP-72/LA-4 cycle for light-duty
vehicles, which is also termed UDDS [19].
In Japan, 6-Mode Cycle, 13-Mode Cycle, and JE05, also called as ED12, introduced
in 2005, based on Tokyo driving conditions, are applicable to diesel and gasoline
HDVs over 3,500 kg (7,709.25 lb). The duration is 1,800 s, the average speed is
26.94 km h-1 (16.73 mi h-1) and the maximum speed is 88 km h-1 (54.65 mi h-1)
[20].
The accelerating and braking properties of the individual driving cycles are
different, and therefore fuel consumption and exhaust gas emissions are not
directly comparable with each other. Although driving cycles are developed on the
basis of country- or city-specific driving conditions, traveling has become more
and more similar on the world. Unified driving cycles would simplify testing
procedures worldwide.
There are two harmonized cycles, the World Harmonized Stationary Cycle and
the World Harmonized Transient Cycle for heavy-duty engines. They can be used
for emission certification and TA worldwide [21, 22].
The fuel consumption of trucks and buses is traditionally tested in the journey
with a standard engine in a standard vehicle, in standard traffic and in standard
environment conditions. The weather must be dry and calm at a certain temper-
ature and a certain air pressure. The examining speed has to correspond to 75% of
the vehicle’s maximum speed. To compensate for uncertainties, the fuel that was
consumed is increased by 10% over the measured distance [23].
4.2 Fuel System in Airplanes 65
There is a direct relationship between the volume of the fuel tank, the structure of the
supply system, and the flow of the fuel to the engine. The fuel supply system of a jet
engine has to regulate opening and closing valves, adjust compressor blades, thrust
exhaust nozzles, and operation of the afterburner. It must avoid thermal and mechanical
overload, prevent unstable compression, and burning when accelerating [24].
The fuel system of airplanes operates under variable air pressures and tem-
peratures depending on flight altitude, which indirectly influences the combustion
chamber temperature, and the compressor pressure.
The fuel consumption of airplane engines depends on the flight phase, i.e., on
the load of the engines; see Fig. 4.5.
main
tank auxillary auxillary
tank 1 tank 2
tank
submerged selector
boost valve
pump defuel or transfer
system
selector refuel valve pump
flowmeters or valve
fuel pressure
engine
gages defuel or
selector
(in cockpit) filters refuel line
valve
engine-driven
left carburetor or right
supply pumps
engine jet controls engine
Gear wheel or piston pumps are used for the high pressure circulation system. The
fuel regulator unit provides the flow that corresponds to the load. The fuel nozzles
distribute the fuel into the combustion chamber. Their number varies according to the
construction of the combustion chamber and the size of the jet engine [27].
The fuel is preheated downstream to the low pressure pump to prevent water
contained in the fuel from crystallizing into ice which could clog the filters and the
regulation valves. The main fuel filter stops particles bigger than 0.03 mm or
1.18 9 10-3 inches [28].
Certain nozzles are used for the starting process and for the higher load ranges.
Double channel burners have a primary and a secondary fuel nozzle. The primary
nozzle delivers fuel during the start and the idle phases. Above these load ranges,
the secondary nozzle takes over the supply of fuel. The diameter of the droplets is
0.05–0.10 mm (1.96 9 10-3–3.94 9 10-3 in). Primary and secondary nozzles
spray droplets into the combustion chamber with an intensive whirl [29].
The regulator of a gas turbine has to provide the proper amount of fuel required
under any operating conditions and has to prevent thermal or mechanical overload.
Operations had to be simplified when flight engineers were excluded from the
cockpit, because there were more input signals to be controlled by two pilots. This
required computers to take over the monitoring function. Fuel management
became more complicated due to the permanent increase of requirements
regarding jet engines as a whole. The earlier hydro-mechanical regulators have
4.2 Fuel System in Airplanes 67
been replaced with a new electronic regulator, the Full Authority Digital Engine
Control (FADEC) [30].
The main elements of the FADEC system are the micro electronic system, the
sensors, and the actuators, and several elements for signal processing, such as
the analog–digital transducers, the multiplexers, and the micro processors. In the
airplane redundancy systems two permanently active channels generate signals,
including sensors for monitoring the power supply. Modern electronic and micro
computer systems enhance the reliability of the FADEC system compared with
hydro-mechanical systems.
Safety is the most important task in aviation. There must be enough fuel on-board
at departure to cover the planned distance, the ground operation needs, and the
amount has to meet the regulations for mandatory reserves including engine failure
and reaching an alternate airport if necessary after takeoff, climbing, cruising,
descent, and landing.
The basic standards regarding fuel are contained in ICAO Annex 6 to the
Chicago Convention, establishing the acceptable minimum level of safety for
international civil flight operations and are reflected in the national codes. The
national codes, such as the Federal Aviation Regulation for US Federal Aviation
Administration and the European Operation Performance Standard (EU-OPS) for
the European Community, may differ from each other, but must not be less
stringent than the corresponding ICAO standard [31]. EU-OPS is very common to
JAA-OPS [32].
Conventionally, the planned route must be in close vicinity of airports so that in
case of an emergency like an engine failure, the airplane must be able to reach an
airport within 60 minutes with one engine inoperative. As a result, instead of
traveling straight, the route may become curved, consequently increasing the trip
distance and the required fuel.
An airline operator has to decide on the amount of fuel on-board with due
regard to IFR for all phases of operation [33].
Figure 4.7 presents the flight segments of a typical trip at an altitude of 1,500 ft
(457 m) above departure to landing at the destination [34].
For safety reasons a departing airplane must have a quantity of fuel on-board
not less than the sum of the amount of:
• Taxi out fuel, the fuel required at the departure airport for ground movement,
i.e., from the gate to the takeoff runway end. It diverges from the final reserve
fuel;
• Trip fuel, the fuel required to fly from departure to destination;
• Route reserve fuel, generally 5% of the required trip fuel quantity;
68 4 Fuel System and Fuel Measurement
fuel for
from TOC
initial climb, to TOD for from TOD from IAP
climb
climb to TOC cruise climb to IAP to 15 m
and descent
The National Aviation Authority may grant ETOPS approval to an airline operator
for certain twin engine jet aircrafts, provided that the operator complies with
special requirements in addition to the conventional flight conduct, including
enhanced reliability, maintenance and operation of the aircraft and training,
checking, licensing of its relevant flight crew and flight dispatch personnel, and the
procedures they must follow [36].
The time limits 90, 120, or 180 minutes are specified in the ETOPS Approval
defining the maximum distance that an aircraft can be further away from an
airport. The ETOPS flight planning rules require that the whole flight path be
covered by the circles drawn with ETOPS time limit radius around selected air-
ports [37].
Those airports must meet strict requirements also for in-flight emergencies and
contingencies such as engine failure or loss of cabin pressure and are called En-route
Alternate Airports (ERA).
Moreover, ETOPS flight planning involves mandatory critical fuel scenario
analysis for each ERA pairs and for each ERA of an ERA pair along the flight
path. The aim of this analysis is to ascertain that fuel actually remaining in the
tanks over a midpoint between two subsequent ERAs will be enough to reach
either of the two ERAs or the original destination airport. The midpoint between
two ERAs must be an Equal Time Point (ETP) [38].
That is, a point requiring equal flight time to reach any one of the two ERAs, i.e.,
the time to fly the distance corrected for wind effects. The analysis must consider
and compute the fuel amount required for cases when both engines operate, i.e.,
long-range cruise and when one engine is inoperative, i.e., cruise with selected
ETOPS speed. Over an ETP rapid decompression must be assumed with an
emergency descent to 10,000 ft (3,050 m), than cruising on 10,000 ft up to ERA.
Over the ERA a descent to 1,500 ft, i.e., 457 m and holding for 15 min follows,
then a missed approach is executed after which an approach and a successful
landing is made [39].
Other items in critical fuel analysis are considered for the required fuel amounts
are:
• Unreliable weather forecasts up to 5%;
• Expected Auxiliary Power Unit consumption up to 2%;
• Low temperatures or icing up to 1%;
• Engine degradation up to 5% [40].
Figure 4.8 presents a critical scenario with ETP conditions considering ERA1
and ERA2.
Except for extra fuel, none of the above-mentioned fuel items are allowed to be
used for purposes other than its specific role, i.e., to cover unexpected delays or
reroutes. So, any time when a flight on its way ought to deviate from its original
plans, a complete re-planning is mandatory. The re-plan shall ensure that the actual
70 4 Fuel System and Fuel Measurement
flight track
ERA2. ERA1.
fuel on-board will cover the new trip fuel, i.e., fuel required from the diversion
point to destination, the new route reserve fuel, alternate fuel, final fuel reserve,
and, if applicable, the new additional fuel amount [41].
Further aspects affecting the fuel plans of airlines:
• Applying known alternatives for route reserves, i.e., contingency, which are
depending on the statistical method approved by the authorities for continuous
measurement and analysis of fuel consumption by the fleet;
• Monitoring of the engine degradation due to wear and tear by aircraft which can
reveal degraded fuel efficiency in addition to performance losses. The degra-
dation as compared to a novel engine can be expressed as a percentage and can
be included in planning the required fuel quantity according to the Emission
Index consideration; and
• Assuming engine failures that occur at the most critical points of the operation.
Fuel systems in ships are used for the supply of the diesel engine. It contains the
fuel system for the daily tank and the setting tank. The fuel system is processed in
accordance with the performance data of the different engine manufacturers and
the physical and chemical properties of fuels. The main elements of processing are
storage, filtration, heating, and pressurizing [42].
Sea-going ships use HFO or IFO fuels to drive the main engines at sea. MDO and
MGO are high-grade fuels of low viscosity, which are used when the vessel is
maneuvering.
HFO is a by-product from refining petroleum. It is warmed to 40C (104F) in
the storage tanks and stored on the raised decks of the ship. This allows the fuel to
4.3 Fuel Systems in Ships 71
MDO MDO
transfer fump emergency
sample
counter
point
MDO
store
join
user IFO transfer pump1 IFO
settling
store 1
tank 1
overrun
flow into tanks in the engine space. A part of the water and mud is already separated
from the fuel in settling tanks which are heated to a temperature of approximately
70C (158F). Water and mud are regularly pumped into mud tanks [43].
Fuel is processed by separating and filtering. Oil synchronous separators are
centrifuges, in which a geared wing pump thrusts the oil through a high-grade steel
plate stack, turning at 12,000 rpm. The conically formed plates are equipped with
separation channels. The purer and lighter oil substances flow into these channels
and the heavy components, like water and dirt, are forced outside and are collected
in a special waste container [44].
To optimally separate fuel, heat exchangers are in front of the synchronous
separators. Their temperature is 70–99C (158–210F) depending on the fuel
density. For heavy marine fuel oils with many pollutants, the separators are
connected in series. The fuel filters in the marine technology are reversible flow
filters. In separate modules, the HFO and IFO fuels are heated to the right injection
viscosity of approximately 12 cSt at 130C (266F) at a pressure of about
(7–10) 9 105 Pa, i.e., 102–145 psi or 14,620–20,885 lbf ft-2 [45].
Heavy marine fuels with high viscosity are pumped into a collection tank at a
pressure of around (6–8) 9 105 Pa, i.e., 87–116 psi or 12,531–16,708 lbf ft-2. The
modern type of injection is the Common Rail technology with a pressure of (200–
300) 9 105 Pa, i.e., 2,901–4,352 psi or 417,711–626,566 lbf ft-2. Common Rail
technology is now mass produced by all marine diesel engine manufacturers [46].
Figure 4.9 shows the plan of a ship’s fuel preparation and supply system
containing tanks for MDO and IFO fuels, transfer pumps, setting tanks, a sample
point, a counter, and a joint user [47].
72 4 Fuel System and Fuel Measurement
In the preparation chain, foreign matter such as liquids and solids are removed
from the fuel. For HFO and IFO fuels, a two-step preparation chain is necessary,
while for distillate fuels such as MDO and MGO, a single-step preparation chain is
sufficient. MDO and MGO are used for maneuvering in harbors or to navigate in
protected sea areas. It is usually stored in MDO and MGO bunker tanks.
On ships the fuel is stored in tanks, which are arranged in the double bottom.
According to the IMO Convention ‘‘Safety of Life at Sea’’ (SOLAS), a minimum
quantity must be stored in tanks, which are not directly endangered in case of
running aground or a collision [48].
In the settling tanks, water and impurities are separated from the fuel and
drained off. The level sensors in these tanks must be robust and have high dura-
bility. From the settling tank, transfer pumps move the fuel through a pre-heater to
a daily tank to preheat the fuel. Temperature and pressure sensors control the
process and maintain a temperature in the supply tanks which is always inde-
pendent of the ambient conditions. If the fuel is too cold it must be warmed before
withdrawal from the tank. The temperature of the fuel should be adjusted in the
daily tank with a final pre-heater. The heat flow density is approximately
1 W cm-2 (3.413 BTU h-1 cm-2, i.e., 22.014 BTU h-1 in-2) [49].
From the pre-heater, the fuel is led to a separator to purify the fuel at the second
cleaning level. The surplus quantity is led back from the overflow of the daily tank
into the settling tank. The level in the overflow tank is continuously monitored and
attached to an alarm system. In the most cases piezoelectric sensors are used to
measure the changing fuel level [50].
From the separator, the fuel enters the two daily service tanks. One tank may be
used while the other is being filled. From the daily service tank the fuel is pumped
to the second heater by the pressure fuel pump. From the heater the HFO and IFO
fuels are passed through a viscosity meter and a regulator to the fuel filter, the flow
counter, and the engine [51].
Engines or boilers, which are operated with different fuel qualities, should be
equipped with a viscosity regulation via magnetic coupling. A connected electric
pump saves a constant volume flow independently on fuel viscosity [52].
On modern ships, there is a flow counter in the transfer pipe which is a propeller
or an oval wheel counter to determine the volume flow similar to the impeller
system. The axis of the rotation must always be installed underneath the pipe axis,
so that the analyzer chambers can be filled with fuel by gravity, depending upon
the kind of fuel. The temperature has to be high enough to guarantee optimal flow
for the continuous measurement of consumption [53].
Figure 4.10 shows the scheme of the fuel store, the pump, and the measuring
system of a ship for MDO and IFO fuels [54].
4.3 Fuel Systems in Ships 73
pre-heater steamer
viscosimeter
filling
separator conduit
drain
valve
atmosphere
inlet
HC
surge drum
alarm
outlet
counter
Fig. 4.11 Tank with hydrocarbon control equipment
The ship must be equipped with fuel to cover its power requirement. The
necessary quantity must be determined before the start of a journey by route
planning based on the relations of:
bPS
B¼ ¼bPt ð4:2Þ
v
.
In this equation the parameters are:
• B the fuel needed for the journey in kg or in lb;
• b the Specific Fuel Consumption of the engine in kg kWh-1 or in oz BTU-1;
• P the propulsion performance in kW or in BTU s-1;
• S the journey distance in nmi, mi ,or km, including drift due to wind in atmo-
sphere and currents in water;
• v the speed of the ship in nmi h-1, in km h-1 or in mph; and
• t the time of the journey in h [58].
The necessary information can be obtained from the fuel management docu-
mentation [59]. Figure 4.12 shows an example of the required fuel quantity as a
function of the ship’s velocity.
Fuel management provides optimal solutions to reduce fuel consumption.
Merchant vessels, such as container ships, drive at a reduced speed to save fuel
since the reduction of the speed from 25 to 20 knots, i.e., 46.3–37.04 km h-1
lowers consumption by about 20–25% [60]. Bulk carriers often deliver perishable
goods; therefore, reducing the speed is not possible. Tankers can usually reduce
speed without encountering any delivery problems. The fastest civil ships are high
4.3 Fuel Systems in Ships 75
250 loaded
100
50
0
13 15 17 19 21 23
1)
knots velocity of the ship [kn]1)
2)
sea miles
Fig. 4.12 Planning the required quantity of fuel for a bulk carrier
speed ferries or hydrofoil boats. They have the highest SFC, and the highest
specific exhaust gas pollution and GHG emissions.
The CO2 index data analysis focuses on optimal fuel consumption. It is an entry
level analysis, which identifies the main factors of voyages with unexpectedly high
or low fuel consumption. The analysis is split into the individual vessels and a
comparison of the fleet’s fuel consumption [61].
Ideally, the CO2 index data of sister vessels are used; see Fig. 4.13.
The result of the CO2 index data analysis can be applied as input for the
Operational Fuel Consumption Analysis, together with data from each ship. The
experience of key crew members and the fleet management is integrated into the
interactive analysis of actual fuel consumption and ranking of improvement
measures.
The global tendencies of the market for fuel products are very similar and are
showing continuous growth in the price structure.
Fuel consumption can be measured in the fuel tank and in the fuel lines of the
vehicles, airplanes, and ships. Dynamic fuel sensors continuously analyze the fuel
flow from the tank to the engine and back from the engine to the tank.
76 4 Fuel System and Fuel Measurement
The principles of the individual flow analyzing methods are different, but all
current technologies are relatively expensive. Most devices measuring fuel flow are
high precision micro system equipment, such as micro wings or micro turbines with
rotation. Other principles are Coriolis mass flow, magnetic induction, and ultrasound
technology. Further sensors use eddy current, thermal mass flow, and pressure flow.
Experiences have proven that vehicles, airplanes, and ships operate more
effectively when using on-board fuel and exhaust gas management which provides
data about the fuel cost per day by monitoring fuel consumption along each route
and passage, combined with other important navigation information. Estimated
parameters can be transferred to the fuel management center, which surveys the fuel
consumed along the route. Planning and budgeting are made easier with a detailed
history of the vehicles’, airplanes’, and ships’ speed and location, direction, fuel
consumption, and emissions. Using the high quality of information obtained by the
system, accountants can also know the fuel prices in each tax region in time and can
recommend the optimal bunker station for the crew to buy fuel.
Monitoring and managing the fuel supply reduces fuel consumption, optimizes
maintenance, ensures in-time delivery, and maintains profit margins. Self diag-
nosis could optimally detect deteriorations caused by natural wear in the engines
by the use of one fuel type and fuel mixtures or by changing the fuel.
References 77
References
1. 80/1268/EEC: Fuel consumption of motor vehicles (16 Dec 1980), amended by 89/491/EEC
(17 July 1989), 93/116/EC (17 Dec 1993), 1999/100/EC (15 Dec 1999), 2004/3/EC (11 Feb
2004)
2. Endres + Hauser: Durchflussmesstechnik. http://www.de.endress.com/eh/sc/europe/dach/de/
home.nsf/systemcontentview/
index.html?Open&DirectURL=D88E971BD4847D91C12573A80039705AVDO:
3. Fuel management (2007) PPL/IR. Europe magazine, November
4. Tank- und Kraftstoff system. 45th International CTI Forum. Stuttgart 31 March–1 April 2009.
http://www.tanksysteme-forum.de
5. Types of fuel pumps. http://www.ehow.com/about_6371177_types-fuel-pumps.html
6. Electrical brushless fuel pump technology. Federal Mogul. http://www.federalmogul.com/
NR/rdonlyres/41941A7A-C69F-44C7-9B7D-BAE03B455B19/0/
BrushlessFuelPumpPresentation.pdf
7. Commission Directive 93/116/EC of December 1993 adapting to technical progress Council
Directive 80/1268/EEC relating to fuel consumption of motor vehicles
8. ECE-R101: Uniform provisions concerning the approval of passenger cars powered by an
internal combustion engine only, or powered by a hybrid electric power train with regard to
the measurement of the emission of carbon dioxide and fuel consumption and/or the
measurement of electric energy consumption and electric range and of categories M1 and N1
vehicles powered by an electric power train only with regard to the measurement of electric
energy consumption and electric range (18 June 2007)
9. 70/220/EEC: Measures to be taken against air pollution by emissions from motor vehicles
(20 03 1970)
10. Council Directive of 26 June 1991 amending Directive 70/220/EEC on the approximation of
the laws of the Member States relating to measures to be taken against air pollution by
emissions from motor vehicles (91/441/EEC)
11. 40 CFR Part 600-113: Fuel economy and carbon-related exhaust emissions of motor vehicles
12. EPA Urban Dynamometer Driving Schedule (UDDS). CFR 40, 86, App. I. http://www.
dieselnet.com/standards/cycles/udds.php
13. HWFET. 40 CFR, part 600, subpart B
14. Emission Test Cycle. http://www.dieselnet.com/standards/cycles/jp_je05.php
15. Save as you drive. Background information for expert fuel savers. VW. March 2009. Article
No. 960.1606.02.18
16. Kraftstoffverbrauch.http://de.wikipedia.org/wiki/Kraftstoffverbrauch#LKW_und_Kraftomnibusse
17. Heavy-Duty Diesel Truck and Bus Engine. http://www.dieselnet.com/standards/eu/hd.php
18. Weltweit leistungsstärkster Rollenprüfstand. http://www.emitec.com/technik/prueffeld-
eisenach/rollenpruefstand-leistungsstarker.html
19. EPA Urban Dynamometer Driving Schedule (UDDS) for heavy-duty vehicles. http://
www.dieselnet.com/standards/cycles/udds.php
20. Test method of heavy duty fuel consumption in Japan. 21 May 2011 http://www.iea.org/
work/2011/hdv/hirai.pdf
21. World Harmonized Stationary Cycle (HWSC). http://www.dieselnet.com/standards/cycles/
whsc.php
22. World Harmonized Transient Cycle (HWTC). http://www.dieselnet.com/standards/cycles/
whtc.php
23. DIN 700010:1990-05. System of road vehicles-Vocabulary of power-driven vehicles,
combinations of vehicles and towed vehicles. Beuth Verlag. Norm. April 2004
24. Fuel system. http://www.encyclopedia2.thefreedictionary.com/fuel+system
25. Fuel tank. http://en.wikipedia.org/wiki/Fuel_tank#Aircraft
26. Hibbert A, Oxlade C, Pickening F (2004) Autos, Flugzeuge, Schiffe. Parragon. ISBN:
1-40543-467-8
78 4 Fuel System and Fuel Measurement
57. Kongsberg: Vessel performance optimizer. Cost efficient vessel operation. http://www.km.
kongsberg.com/ks/web/nokbg0397.nsf/AllWeb/302A1A3175AB5D4DC12574CC0045D82A/
$flie/KM-Vessel-performance.pdf?OpenElement
58. Bright hub: bunkering operations: precautions, checklist, calculations & corrections
explained. http://www.brighthub.com/engineering/marine/articles/35476.aspx
59. Fuel measurement and management system. http://www.parker.com/portal/site/PARKER/
menuitem.7100150cebe5bbc2d6806710237ad1ca/?vgnextoid=f5c9b5bbec622110VgnVCM
10000032a71dacRCRD&vgnextfmt=DE&vgnextdiv=&vgnextcatid=2656571&vgnextcat=
FUEL%20MEASUREMENT%20AND%20MANAGEMENT%20SYSTEMS.12574CC00
45D82A/$file/KM-Vessel-performance.pdf?OpenElement
60. Clean north sea shipping (CNSS). http://www.cleantech.cnss.no/ghg-technologies/operational-
measures/operational-speed-reduction/
61. Germanischer Lloyd (2008) CO2 index data analysis. Nonstop. The Magazine for Customers
and Business Partners. Hamburg, pp 33. OE 003. publications@gl-group.de
Chapter 5
Emissions
Transportation produces exhaust gas emissions. The products are gases, particles,
noise, and heat. However, pollutants can be emitted not only by engines but also
by other devices such as fire extinguishers, fuel tanks, and refrigerators on vehi-
cles, airplanes, and ships. Most emissions are produced by the burning process in
internal combustion engines [1].
Combustion produces several types of substances, which intensively influence
the atmosphere [2]. Diesel and kerosene contain approximately 85% carbon and
15% hydrogen [3], petrol has a higher concentration of hydrogen. They theoreti-
cally burn according to the equations [4]:
12 kgC þ 32 kgO2 ! 44 kgCO2 þ 407; 500 kJ ð5:1Þ
1 kg diesel fuel or kerosene emits approximately 3.15 kg, i.e., 6.95 lb of CO2.
Conversion from mass to volume depends on density. 1 l of gasoline produces
about 2.32 kg, i.e., 5.11 lb CO2. Burning 1 l of diesel fuel or kerosene emits about
2.32 kg, i.e., 5.11 lb of CO2. 1 l of liquefied petroleum gas emits 1.8–2.0 kg, i.e.,
3.96–4.41 lb CO2, depending on the proportion of C to H atoms in the fuel [6].
The fuel consumption of 5.6 l 9 (100 km)-1, i.e., 0.305 gal mi-1 (US) or
0.41 gal mi-1 (UK) petrol results in the emission of 130 g km-1, i.e.,
4.585 oz km-1 or 7.384 oz mi-1 CO2. This is the current European level for car
emissions in NEDC [7].
Burning 1 t diesel fuel or kerosene emits 1.24 t, i.e., 2 733 lb of water vapor.
Emissions of H2O vapor on the Earth are much higher than the CO2 emissions, due
to the large surface of the oceans but water vapor does not negatively influence the
climate, with the exception of the emissions of airplanes at higher altitudes [8].
In practice, a small volume results in not completely burned end products of
oxidation, such as CO and several hydrocarbon (HC) substances or oxidation
products made of atmospheric nitrogen, such as NO and NO2. Substances such as
CO, HC, NO, NO2, and SO2 are pollutants and dangerous to human health. They
are not stable products because OH radicals change them from their intermediate
state to end products in the atmosphere:
CO þ OH ! CO2 þ H: ð5:4Þ
A modern self ignition engine combusted by diesel fuel and a jet engine com-
busted by kerosene produce on average 3 kg (6.6 lb) of CO per 1.0 t (2,204 lb) of fuel
[9]. Depending upon the type of internal combustion engine and the range of use, the
value varies between 1.1 kg (2.4 lb) and 8.7 kg (19.2 lb). Global human CO emis-
sions amount to approximately 1,077 9 106 t (2,372 9 109 lb) per year [10].
Transportation emits approximately one-fifth of the total CO amounts.
Unburned HCs are the ultimate products of combustion and can react to
intermediate and later to heterocyclic aromatic organic substances, which are
carcinogenic:
CH 4 þ OH ! CH 3 þ H 2 O: ð5:5Þ
Self ignition and jet engines emit approximately 0.7 kg (1.5 lb) of unburned
HCs per 1.0 t (2,204 lb) of fuel on average. The mass varies between 0.1 kg
(0.22 lb) and 3.5 kg (7.7 lb) [11]. The amount of world anthropogenic HC pro-
duction is approximately 275 9 106 t (606 9 109 lb) per year.
Depending on the quality of combustion, between 6 kg (13.2 lb) and 20 kg
(44.1 lb), on average of 14.7 kg (32.4 lb) of NO per 1.0 t (2,204 lb) fuel is
produced, mainly due to the high temperatures in the combustion zone where the
nitrogen molecule dissociates and finally oxidizes [12]:
O2 þ N ! NO þ O: ð5:6Þ
The annual global NOx (NO plus NO2) emissions are 195 9 106 t i.e.,
430 9 109 lb. Most of them (156 9 106 t, i.e., 338 9 109 lb) are caused by
5.1 Physical and Chemical Properties of Combustion Products 83
human beings through industry, transport, and domestic heating. Cars and trucks
emit approximately 33 9 106 t of NOx. Both, the shipping and the aviation
industry individually emit about 2.5 9 106 t, i.e., 5.51 9 109 lb per year, which is
commonly 5.0 9 106 t year-1, i.e., 11.01 9 109 lb year-1 or 15% of the NOx
exhaust masses caused by transportation [13].
Sulfur (S) burns with the oxygen of air and produces sulfur dioxide (SO2).
S þ O2 ! SO2 ð5:7Þ
6
Anthropogenic sulfur dioxide emissions are approximately 150 9 10 t, i.e.,
331 9 109 lb per year [15].
On the basis of the maximum value of the sulfur content in kerosene and
gasoline, according to international standards, approximately 5 kg (11 lb) of SO2
is emitted per 1.0 t (2,204 lb) of fuel. However, in practice the emissions might be
substantially lower owing to better fuel quality. SO2 causes acid rain which affects
nature and also causes several diseases, and dangerous processes for human health
and infrastructure [14].
Table 5.1 shows the properties of air and of gaseous components in air [16].
In both, the short- and the long-term scenarios, reducing fuel consumption and
exhaust gas emissions constitute the two most important topics of transportation.
Definitions for emission analyzing technology are similar in all sectors of trans-
port, i.e., road traffic, aviation, and maritime shipping. The measurement proce-
dure and the equipment for the Type approval and the Type certification can be
divided into four main groups; see Fig. 5.1.
84 5 Emissions
R&D I&M
expensive moderate cost device to test
scientific instruments quality
TA & TC OBD
expensive large certified inexpensive micro sensors and
analysers for basic tests of actuators for saving data during
quality normal operation
Fig. 5.1 Instruments for measuring emissions in the whole life cycle of transportation
Emissions of vehicles’, ships’, and airplanes’ engine are usually tested at test
benches. The example in Fig. 5.2 shows the analysis of exhaust gases behind a jet
engine [18].
5.2 Measurement of Emissions 85
- stressed wires
- sampling point
- stainless steel gas pipe
measuring unit
Fig. 5.2 Test bench for the control of jet engines emissions
The exhaust gas can be taken via a stainless steel gas pipe behind the engine in
the exhaust gas pipe.
The measurement devices are basically the same for vehicles, airplanes, and
ships.
• Chemo Luminescence Detector (CLD) for NOx, NO, and NO2;
• Flame Ionization Detector (FID) for HC;
• Fourier Transformation Infra Red (FTIR) spectrometers for CO and CO2; and
• Opacimeters, and filter-based or photo acoustic methods for smoke and particle
measurements.
In all means of transportation sensors are used for recording data. Sensors convert
physical or chemical parameters into an electric signal on a miniature scale. The
analog input signals may be steadily linear, steadily nonlinear, or repeatedly
stepped. The output signals are current, tension, amplitude, frequency, etc., which
are analog and can be changed to a binary digital form [19].
The common mechanical, physical, chemical, electrical, magnetic, and climatic
conditions in vehicles, airplanes, and ships define the placement of sensors. Sen-
sors must:
• Steer, brake, and protect all operational processes if necessary;
• Monitor the engine, transmission, undercarriage, wheels, and tires; and
• Inform the driver or the captain of the performance, the fuel consumption, and
the emissions.
86 5 Emissions
A small size and a low price are the main preconditions for the wide ranging use
of sensors in transportation. There are different methods for the miniaturization of
sensors and actuators [20]:
• Combination of micro mechanical, micro electrical, and micro optical engi-
neering production methods;
• Utilization of uniform and flexible multibus interfaces, which is a standard
application in industrial computer systems;
• Combination of multi layer, hybrid, and semiconductor technologies;
• Application of small measurement errors with highly developed tuner
amplifiers;
• Changing analog signals to High Frequency signals for data transfer with low
hysteresis;
• Correction of sensor deviations at the measurement site;
• Comparison of measured values with stored basic values and compensation of
the sensor signals; and
• Storage of corrected information in the Electronic Programmable Read-Only
Memory (PROM)
Temperature, pressure, speed, number of revolutions, and inclination sensors
are widely used in all means of transportation. The direct analysis of combustion
products is still not state of the art and is one of the hardest measurement tasks.
One exception is the solid electrochemical technology for oxygen measurement.
These sensors are called Lambda tubes, operate with zirconium dioxide, and
optimally measure the O2 concentration in the exhaust gas in two places—
upstream and downstream of the catalyst. The measuring tube consists of an
integrated heating element and provides the necessary operating temperature of
600C (1,112F) [21].
A changed form of Lambda sensor measures the NO concentration. Similarly
designed solid electrolytic measuring cells can be used for the analysis of
unburned substances such as CO and HC. Semiconductor and metallic oxide
sensors do not have the required accuracy and selectivity yet.
Anemometers, and Pitot and Prandtl tubes are important elements for the air
mass flow estimation in the air intake system for the combustion engine mea-
surement technology. The first operates with a heated wire, and the second with
combined pressure, sensors. The detector elements are usually installed in a
Wheatstone bridge to improve the precision of the signals [22].
The measurement of the mass flow of the exhaust gas is a very complicated
technology because of high temperatures and pressures, and fast changes of the
physical and chemical parameters in the combustion chamber and in the exhaust
gas after treatment system. The mass flow of individual combustion products in the
bend pipe of the combustion chamber and in the end pipe of the exhaust gas after
treatment system can be estimated only with highly complex technology to
achieve the required accuracy.
5.2 Measurement of Emissions 87
There are several optical remote sensing methods to measure the composition of
exhaust gases, e.g., when flying over ships with airplanes. Laser analyzers,
installed on the test airplane, measure the composition of the exhaust gas emitted
from the smoke stack. These methods are very expensive and are used only in
protected areas to control the ship’s real emissions. Similar methods have been
used at airports for analyzing the emissions of taxiing and taking-off airplanes.
The detection system measures the emissions using the absorption of laser signals
from the reflected optical path. The lowest concentrations, which can be detected,
are 0.5–1.0 ppm of CH4, 2.0–3.0 ppm of CO, 10.0–20.0 ppm of NO, and 0.5–
1.0 ppm of CO2. The resolution of laser operated remote sensing devices generally
presents a very high quality measurement technology with clustered, coherent laser
beams, not only at the test bench but under natural conditions too. Remote sensing
systems cost from 20,000 to several hundred thousand Euros or US Dollars [23].
Monitoring combustion in the engines of vehicles, ships, and airplanes can be
done in several phases. In the research and development phase, large, expensive,
and locally fixed systems in laboratories are usually used. These devices can detect
very small concentrations, provide large measuring ranges, and display extremely
short-term events. They can also measure a wide range of different gases at the
same time. However, the mobile application of these devices is very limited and
transport of them is, in most cases, not possible.
12.0 12.0
characteristics
4.0 4.0 normal
function
0 0
0 200 400 600 800 1 000 1 200 0 200 400 600 800 1 000 1 200
[°C] exhaust gas temperature [°C]
120
thrust [kW]
deterioration
80 normal
function
40
0
0 200 400 600 800 1 000 1 200
exhaust gas temperature [°C]
0 0 0
takeoff cruise takeoff cruise takeoff cruise
Cruising altitude is 10 650 m (34 984 ft), speed is 850 km*h-1 (459 mi*hr-1)
Fig. 5.4 Comparison of average fuel consumption and emission data in takeoff and cruising of
engine type A310/CF6-80
steel protection
wall
1 2 3 4 5 6 7
concentration 1 500
CO [ppm]
750
0
concentration 90 000
CO2 [ppm] 45 000
0
1 500
concentration
NO [ppm] 7500
0
2 4 6 8 20
time [min]
1. 3. 7. low rpm 5. high level rpm
4. middle rpm 4. 6. very high level rpm
Fig. 5.6 Tendencies of the exhaust gas concentrations of a supply ship while idling in harbor
CO2 emissions from ships can help determine emission trading fees and pollutant
emissions can be used to calculate harbor fees, both on the basis of real emission
data.
Certified large analyzers, such as Chemo Luminescent Detectors (CLD) are used at
the engine test bench for the determination of the concentrations of nitrogen
monoxide and nitrogen dioxide. The concentration of unburned HCs is determined
using FID devices. Carbon monoxide and carbon dioxide concentrations are
determined through gas absorption with FTIR spectrometer. Particle and soot
emissions are measured by optical, photo acoustic, or filtering devices. This
equipment is usually used in laboratories. Because of their sensitivity to vibration
and their high energy demands, these devices can be applied only for short periods
for mobile operations in the field.
Laser technology opens up several possibilities for remotely sensing exhaust
gas emissions in transportation. The outputs of vehicles can be measured by highly
92 5 Emissions
precise laser analyzers at the edge of the road or on bridges of the highway. The
exhaust gases of jet engines near and at airports and of ship engines near and in
harbors can also be determined by stationary remote sensing equipment.
Exhaust gas emissions of vehicles are measured at engine test and dynamometer
test benches with certified, large analyzers. Most precise instruments are sensitive
to vibration, so they may be used if they can be positioned without move.
Moreover, they are not suited for hard real traveling conditions during driving.
Due to the high energy demand, the time interval of use in the field is limited.
Micro sensors present a useful way to monitoring real operations. They always
have to be combined with a micro controller system for in situ amplifying, cor-
recting, and linearizing of measured signals.
There are two ways to lower the exhaust gas emissions of vehicles.
• Building new transportation systems with a high technical level of on-board
monitoring; and
• Retrofitting the existing fleet with additional monitoring and regulating devices.
Retrofitting private cars is usually too expensive. However, heavy-duty vehicles
could be advantageously retrofitted with adequate Self Diagnosis.
Vehicle engines have become more intelligent through the introduction of
advanced micro temperature and pressure sensors in the combustion chambers.
They already provide a new control quality of highly dynamically changed
parameters of burning processes. The tendency will lead to the combination and the
integration of sensors, actuators, and micro computer systems for sensing, acting,
and data processing. Future vehicles will become intelligent tools with the highest
possible efficiency for transport, information, communication, and entertainment.
Since 1993, measurements of exhaust gas emissions of a single engine have been
performed at the manufacturer’s test facilities as part of the certification process, in
compliance with requirements of ICAO international standards and recommended
practices of Annex 16 to the convention of international civil aviation.
In addition to the test bench, the emissions of the airplane’s engine can be
measured on the airplane during idling and taxiing at the airport with help of the
‘‘Driving behind’’ method. Disadvantageously, the results depend in a great extend
on weather conditions. Specific aviation measuring technology with the ‘‘Flying
behind’’ method provides realistic and very precise results. However, experiments
at high altitudes are dangerous and expensive.
5.6 Summary and Recommendations: Emissions from Transportation 93
Airplanes emit the highest amounts of NO, NO2, and particles in the takeoff
phase near airports. To monitor pollutants from aircraft in this situation, the ICAO
established emission measurement procedures and compliance standards for soot,
measured as Smoke Number, unburned hydrocarbons, carbon monoxide, and
nitrogen oxides for procedures at aircrafts. Highly precise emission analysis
devices in environmental measurement containers can estimate the distribution of
exhaust gas components in the atmosphere, but the allocation of peaks to indi-
vidual airplanes depends on weather conditions. That is why the landing and the
takeoff cycle (LTO cycles) of an airplane is defined with test bench data which
provide precise conditions for comparison.
Aircraft operators can contribute to the reduction of pollutants in the exhaust
gas by running and acting upon the results of an engine degradation monitoring
program.
Monitoring the emissions of exhaust gases in the smoke stack can precisely
characterize the operation of a ship’s engine. Higher concentrations of exhaust gas
products in comparison with the normal level can be used as recommendations for
early maintenance or for engine repairs.
Near harbors, remote sensing methods can be applied to control exhaust gas
emissions, but fast changing ambient air temperatures, pressure, humidity, wind
speed, and wind direction often make it impossible to use the signals to create
clear decisions concerning the sources of emissions, although it allows to regulate
levying taxes based on exhaust gas emissions.
To reduce fuel consumption and pollutants in the atmosphere of harbors,
management has to consider not only energy saving methods in the operation of
ships, but also possibilities for improving the on-shore energy supply in harbors
and replacing conventionally fuelled duty vehicles for logistic with environmen-
tally friendly driven vehicles. Emissions of public and private cars, and logistic
vehicles can cause a very high local concentration near parking garages and ter-
minals at harbors. The use of alternative fuels in heavy duty vehicles, public buses,
and cabs can intensively decrease emissions in harbors.
References
1. Combustion. http://en.wikipedia.org/wiki/Combustion
2. What is the balanced equation for the combustion of kerosene? http://en.wiki.answers.com/Q/
What_is_the_balanced_equation_for_the_combustion_of_kerosene
3. Emission facts: average carbon dioxide emissions resulting from gasoline and diesel fuel.
EPA420-F-05-001 February 2005. http://www.epa.gov/oms/climate/420f05001.htm
4. Fuel chemistry. http://www.altfuels.org/backgrnd/fuelchem.html
94 5 Emissions
injection
pump
actuator
engine generator
impulse receiver
3
1 analogue
electronic module 4
2 desired value
5
signal between 0 and 1.1 V. Digital systems transform continuous analog signals
to discrete digital signals which represent two states, zero and a higher level one.
They are more precise than analog signals and can be processed by computer
controlled software. Digital circuits are usually more expensive and need a higher
supply power than analog systems [3].
Digital parameters are the number of revolutions or individual positions in the
engine which can be measured with impulse receivers. Digital–Analog Converters
(DAC) convert digital signals to analog signals to drive electric motors or regulate
actuators in vehicles, airplanes, and ships [4].
The hardware consists of electronic components on a printed circuit board
equipped with analog elements, such as resistors, condensers, switchers, connec-
tors, plugs, etc., and digital elements, such as integrated circuits and micro con-
trollers (lC) [5].
The software is stored in the micro controller or other chips on the electronic
circuit, typically in an Electrically Erasable Programmable Read-Only Memory
(EEPROM) or flash memory. A micro controller is a small computer on a single
integrated circuit containing a processor core, a memory and a programmable
input or output peripherals. Programmable control units do not have fixed char-
acteristics and can be reprogrammed by the user or the operator for several
measures which are not essential for the basic functioning of the system [6].
In ships, digital systems may communicate text from Computer-Aided Dispatch
(CAD). Digital processing, combined with the relatively narrow receiver bandwidths,
provides a high quality of signal transmission with resistance to noise and fading [7].
Electronic systems secure more and more complex in all types of transportation
means, i.e., in road vehicles, airplanes, and ships (see Fig. 6.2).
6.2 Vehicles’ Electronics 97
electronic
on-board system auxiliary device
hardware system
In the past, fuel injection, ignition timing, idle speed, variable valve timing and
valve operation etc., were directly controlled by mechanical, pneumatic and
hydraulic sensors, and connected analog electronic modules. Electronics is one of
the most intensively developed fields in transportation [8].
The main element of the current electronic system is the Electronic Control Unit
(ECU). It is an embedded system that controls one or more of the electric and
electronic systems, and the subsystems in a vehicle. Recently developed ECUs are
equipped with a data logger which records all sensor signals using highly devel-
oped software in an on-board installed and operating micro controller system.
Some modern vehicles have up to 80 ECUs, including engine, transmission,
telephone, body, door, seat, indoor air condition, speed, convenience control units
and Man–Machine Interfaces (MMI) [9].
Current ECU technology monitors many functions in vehicle systems such as:
• The idling speed which determines the timing of the fuel injection with the
crankshaft position;
• The engine cycle which opens and closes the intake air and fuel, and exhaust gas
valves;
• The ignition which determines when the spark plugs should fire;
• The revolution limiter which limits the highest number of revolutions allowed in
the engine;
• The cooling water temperature correction which is needed to regulate additional
fuel consumption when the engine is too cold or dangerously hot;
• Transient fuelling, i.e., a specific amount of fuel when the throttle is opened;
• Fuel pressure modification which increases or decreases the timing of the fuel
injection to compensate for a drop in fuel pressure;
98 6 Electronic Systems and Computer Technology
• The first Lambda sensor signal which monitors the O2 concentrations in the
exhaust gas after treatment system and modifies the fuelling to achieve a stoi-
chiometric combustion; and
• The exhaust gas mass at the waste gate which regulates the operation of the
turbocharger [10].
Comprehensive ECU systems are essential elements in modern vehicles.
Nowadays, modern vehicles cannot be built without ECU technology. Speed and
course regulation, and driving stability, low consumption and emission quotas in
extreme situations, are special examples of optimal management with help of
intelligent electronic control systems.
In modern vehicles, nearly all electric and electronic components in engine, trans-
mission, steering, braking and other systems are monitored. The measured values,
which are taken from sensors, are checked according to their plausibility by com-
parison of the individual signals with stored reference values. Moreover, all electric
circuits are checked for ground defects, short circuits, and breaks in the wires.
The general ECU diagnostic functions can be grouped in:
• Self-monitoring checks
– Controlling the micro controller modules such as Central Processor Unit
(CPU), Arithmetic Logic Unit (ALU), static and dynamic Random Access
Memory (RAM), EEPROM, electronically programmable flash memory for
data storage, ADC and DAC converters.
• Periphery checks
– Controlling the sensors and actuators for availability and functionality.
• Communication diagnostic checks
– Monitoring messages and signals on different communication lines.
6.2 Vehicles’ Electronics 99
auto control
• Plausibility checks
– Functional monitoring all operation processes, if the detected condition could
arise and uncover complex failure modes or deteriorations [12].
An appropriate error code is stored for any recognized fault, which can be
designed as a warning signal in the diagnosis system (see Fig. 6.3) [13].
In addition to possible disturbances in the main engine and in the exhaust gas
after treatment system, deteriorations in other components can also lead to
increased fuel consumption and higher exhaust gas emissions. Optimal control and
regulation needs a comprehensive electronic system.
Flight Management Systems (FMS) integrate diverse and independently operable air-
craft electronic systems to aid the flight crew in managing the automatic pilot, optimizing
in-flight performance, and monitoring fuel consumption at flight deck displays [15].
100 6 Electronic Systems and Computer Technology
The FMS has one or more Flight Management Computers (FMC) which work
with [16]:
• Flight plan information which is set by the crew;
• Airplane system data;
• Performance data including airplane drag and engine characteristics, maximum
and minimum speeds, and maximum and optimum altitudes. The flight crew
may display these parameters on a Control Display Unit (CDU) instead of
referring to a performance manual during flight; and
• Navigation data with the database which includes nearly all information that is
portrayed on conventional navigation charts. It can be depicted on navigation
displays or on the CDU [17].
FMC receives fuel data from the system indicating fuel quantity and predicts
performance based on the last valid fuel quantity with periodic update inputs for
the estimated fuel weight that is needed to keep the current gross weight data. A
message informs the crew when no update has been performed within the pre-
scribed time or when an unexpected drop in fuel quantity is detected. The content
of an automatic FMC report transmitted at pre-defined points can be a message
from the ground to the FMC. Most of them require a pilot action to be accepted.
However, there may be messages that are automatically loaded into the FMC.
The computer technology serves commands and information required to roll on
ground, and to fly an optimum altitude and direction through climbing, cruising,
and descenting. The most important commands and information are:
• Pitch, roll, and thrust commands;
• N1 rotation limits, N1 rotation targets, and commands to flight speed; and
• Position data with the computed position, which is continually updated by
signals from on-board radio navigation, Inertial Reference System (IRS), and
Global Positioning System (GPS) depending on the airplane equipment [18, 19].
The information is passed to the Autopilot Flight Director System which
includes two separate Flight Control Computers (FCC) [20]. They send control
commands to their respective pitch and roll hydraulic systems. The flight control
operates with two separate hydraulic systems and moves F/D command bars on the
altitude indicator [21].
The Auto Throttle system (AT) provides automatic thrust control by computing
the required thrust level and moving the thrust levers with servo motors which
equalize thrust through the electronic engine controls while CDUs receive map and
route information [22].
The pilot selects the desired information for the navigation and supervises the
operating modes of the autopilot on the control display of the Electronic Flight
Instrument System (EFIS) [23].
6.3 Airplanes’ Electronics 101
A turbofan engine consists of two mechanically independent rotors [24]. One rotor
operates inside the other. The main elements are:
• Fan;
• Low pressure compressor;
• Low pressure turbine installed on the inner rotor called N1 rotor; and
• Outer rotor called N2 that holds the high pressure compressor and high pressure
turbine.
The engine fuel and oil system include:
• Valve for passing the fuel to the engine;
• Pump to increase fuel pressure;
• Fuel and an oil cooler and heater;
• Fuel filter;
• Pump to further increase fuel pressure;
• Shut off valve before the combustion chamber; and
• Fuel flow meter providing flow information to the FMS.
The basic parameters of the engine are:
• N1 and N2 rotation speeds;
• Exhaust Gas Temperature;
• Oil pressure, oil temperature, and oil quantity;
• Fuel flow and filter saturation;
• Engine vibration;
• Fuel valve position; and
• Engine failure alert indication.
Theoretically measurement devices for combustion products and exhaust gas
substances can be installed in two zones (see Fig. 6.4) [25].
Measuring parameters are indicated and displayed in the cockpit, and compared
with their operating and calculated ranges.
The mechanical or electronic engine control system senses the position of the
thrust lever, and compares actual and target N1 to the aircraft’s configuration and
altitude. It automatically sets engine thrust by adjusting the fuel flow to achieve the
target N1, controlled by the auto throttle system or by the pilot.
Flight instruments give information to the pilot about the aircraft’s speed, direction,
altitude, present position, and spatial orientation. Power plant instruments provide
data about the status of the aircraft’s engines and the APU. System instruments give
102 6 Electronic Systems and Computer Technology
1. 2. 3. 4. 5.
fan
nozzle
6. 7. 8. 9.
an overview of the aircraft’s other systems, such as the fuel delivery, the electric
subsystems, and the pressurization.
Signals can be displayed on computerized Cathode Ray Tubes (CRT) or Liquid
Crystal Displays (LCD) in the cockpit [26, 27]. Pilots can monitor the status of the
data link systems on the CDU monitor which gives access to maintenance
personnel while the aircraft is on the ground. The flight recorder permanently
records data about the flight’s conditions and the airplane’s operating performance.
Maintenance personnel can enter correction factors for drag and fuel flow to
refine the database. The recorded data can be used for maintenance and for further
statistical analysis activities.
On-board sensors are designed to measure and transmit signals from the engine
and the complementary systems to the ship’s bridge and gate commands to
6.4 Ships’ Electronics 103
I
Sw
5 A
1 2 3 4 D
Im 6 C
E
7
P
monitor the state of the sensors and to regulate actuators such as stepped motors,
electro-magnetic and electro-mechanical valves, piezo switchers, and pneumatic
and hydraulic cylinders, etc., from the bridge [28].
All electronic equipment for use on ships is constructed according to sea
conditions because sea sensors and actuators can come into contact with salt water.
Therefore, the casings are produced to be corrosion resistant and waterproof.
The integrated bridge is the central element for the monitoring and steering of the
ship. The bridge receives inputs from various sensors, electronically displays the
signals, collects positioning information, and provides regulation and steering
signals required to keep the vessel on course [29].
The navigator becomes more and more a system manager interpreting the ship’s
movements and monitoring the vessel’s performance (see Fig. 6.5).
The communication with other systems, e.g., with the fuel management system,
the air conditioning, and the refrigerator monitoring system can be managed using
a standardized CAN bus system. Common interface technology makes it possible
to store data and follow error signals [30].
104 6 Electronic Systems and Computer Technology
There are a wide variety of marine electronics on the market (see Table 6.1).
The Vessel Traffic Service (VTS) is a system for identifying and locating vessels
by electronically exchanging data with other nearby ships and other VTS stations
6.4 Ships’ Electronics 105
Vehicles, airplanes, and ships use analog and digital technology in electronic sys-
tems. The hardware consists of active and passive electronic elements. The software
is usually contained in the EEPROM or the flash memory. Nowadays, electronic
systems use digital micro controllers and regulate all related operation functions.
Electronic systems are important in airplanes due to the rapid movement of the
aircraft with changing weather and terrain. In contrast to road vehicle and ship
navigation technique, the flight takes place in a three-dimensional space with the
fourth dimension, time.
In flight pilots are faced with extremely demanding tasks to fly safely. There-
fore, on-board electronic systems are designed with the primary aim of alleviating
the pilot’s workload and enhancing safety. Besides safety, a lot of electronic
subsystems ensure optimum and cost-efficient operation to keep airlines profitable
in the highly competitive air transport market.
Flight instruments give information to the pilot about the aircraft’s speed,
direction, altitude, and orientation. Power plant instruments provide data to the
status of the aircraft’s engines and the APUs. System instruments give an overview
of the aircraft’s other systems, such as the fuel delivery, the electric system, and
the pressurization.
The continuous expansion of electronic systems on the aircraft has led to a higher
demand for energy on-board, similar to road and ship energy supply technology.
References
1. Electronics. http://en.wikipedia.org/wiki/Electronics
2. Speedometer. http://en.wikipedia.org/wiki/Speedometer
3. Electronic circuit. http://en.wikipedia.org/wiki/Electronic_circuit
4. Digital Analog Conversion. http://www.opamp-electronics.com/tutorials/digital_theory_ch_
013.htm
5. Microcontroller. http://en.wikipedia.org/wiki/Microcontroller
6. A family of user-programmable peripherals with a functional unit architecture. http://
www.ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=126539
7. Computer aided dispatch. http://en.wikipedia.org/wiki/Computer-aided_dispatch
8. Engine control unit. http://en.wikipedia.org/wiki/Engine_control_unit
9. Electronic control unit. http://en.wikipedia.org/wiki/Electronic_control_unit
10. Electronic Control Unit ECU. http://www.autorepair.about.com/cs/generalinfo/l/bldef_160.htm
11. Controller area network. http://en.wikipedia.org/wiki/Controller_area_network
12. Nedians: The electrical system (an overview). http://www.nedians.8m.com/Starting.html
13. Bosch (1999) Kraftfahrzeugtechnisches Taschenbuch. 23. Auflage. ISBN: 3-528-03876-4
14. Avionics. http://en.wikipedia.org/wiki/Avionics
15. Flight management system. http://en.wikipedia.org/wiki/Flight_management_system
16. Flight management computer. http://www.b737.org.uk/fmc.htm
17. Flight instruments. http://en.wikipedia.org/wiki/Flight_instruments
18. Inertial reference system. http://www.digilander.libero.it/andreatheone/irs.htm
19. Global positioning system. http://de.wikipedia.org/wiki/Global_Positioning_System
20. Flightgear. http://en.wikipedia.org/wiki/Flightgear
21. Flight control. http://www.f20a.com/f20fces.htm
22. Autothrottle. http://en.wikipedia.org/wiki/Autothrottle
23. Electronic flight instrument system. http://en.wikipedia.org/wiki/Electronic_Flight_Instrument_
System
24. Turbofan. http://www.fromtheflightdeck.com/Stories/turbofan/
25. Turbofan. http://en.wikipedia.org/wiki/Turbofan
26. Cathode ray tube (CRT). http://www.searchcio-midmarket.techtarget.com/definition/cathode-
ray-tube
27. Liquid crystal display. http://en.wikipedia.org/wiki/Liquid_crystal_display
28. Marine insight. http://www.marineinsight.com/tech/proceduresmaintenance/how-to-install-
electronic-circuits-on-ship/
29. Partners in technology. Imtech Marine. Integrated Bridge System. The future stars today!
http://www.imtech.eu/smartsite.dws?lang=EN&rid=24219
30. Marine fuel management. http://en.wikipedia.org/wiki/Marine_fuel_managemen
31. Autopilot for ships. http://www.nauticexpo.com/prod/kongsberg-maritime/autopilots-for-
ship-31233-191085.html
32. Chartplotter. http://en.wikipedia.org/wiki/Chartplotter
33. Compass. http://en.wikipedia.org/wiki/Compass
34. Sonar. http://en.wikipedia.org/wiki/Sonar
35. Marine VHF radio. http://en.wikipedia.org/wiki/Marine_VHF_radio
36. Digital selective calling. http://www.inmarsat.com/Maritimesafety/dsc.htm
37. Radar. http://www.helzel.com/files/432/upload/Pressreleases/WERA_EJN_3-09-2.pdf
38. Vessel traffic service. http://en.wikipedia.org/wiki/Vessel_traffic_service
39. Automatic identification system. http://de.wikipedia.org/wiki/Automatic_identification_system
40. What are the amendments to the IMO performance standard for ECDIS? http://www.e-
navigation.com/reference/tag/imo
41. Ship plotter. Automatic identification system. http://www.coaa.co.uk/shipplotter.htm
Chapter 7
Aerodynamics of Vehicles and Airplanes,
and Hydrodynamics of Ships
The aerodynamics of vehicles and airplanes, and the common hydro- and
aerodynamics of ships determine all events which influence the flow around
vehicles, airplanes, and ships. Resistance causes draught which results from the
shape of the means of transportation designed by manufacturers and is decisive for
the aerodynamics of road vehicles and airplanes, and the common aero- and
hydrodynamic properties of ships.
The resistance factors are called the cR and cW values and can be optimized
through the body design and by streamlining.
There are still considerable potentials for improvement in road vehicle technology.
In this sector, the improvement of the cR value by several technological measures
leads to a valuable decrease in average fuel consumption from about 1 to 2% at
40 km h-1 (24.9 mi h-1) and from 4 to 8% at 120 km h-1 (74.6 mi h-1);
see Fig. 7.1.
10.0
Opening headlight
relative fuel consumption [%]
5.0
Conventionally running
tyres
2.5
Smooth running tires
0
40 60 80 100 120
velocity [km*h-1]
The power needed to overcome air resistance grows with the square of the
velocity. Therefore, slower driving to reduce air resistance is the most important
measure for drivers to lower fuel consumption; see Fig. 7.2 [3].
7.1 Aerodynamics of Vehicles 111
40.0
The rolling resistance of tires impacts the total fuel consumption in passenger cars
by approximately 10–15%. Modern commercial vehicles automatically monitor
the pressure in the tires. Smooth running tires and light running oils decrease
rolling resistance and lead to lower fuel consumption and exhaust gas emissions.
The rolling friction of the tires is affected by the applied construction, the used
material and the internal pressure. At 20 km h-1 (12.4 mi hr-1), rolling resistance
is nearly 100% of the external resistance acting on the car and still makes up 60%
of the external resistance at 50 km h-1 (31.1 mi hr-1). The fuel saving rates are
smaller but also similar in heavy commercial vehicles [4].
The aerodynamics of airplanes depends on the interaction of moving air with the
surface of the aircraft [5]. The main resistance factors are:
• Fuselage: 0.02–0.05;
• Engine and nacelle: 0.10–0.15;
• Tail unit with horizontal and vertical stabilizers: 0.01–0.02;
• Wing and connecting parts: 0.2–0.3; and
• Winglet: 0.01.
Improved aerodynamics reduces fuel consumption and thus also CO2, NO, NO2
and particle emissions. The aerodynamic drag depends on the quality of the sur-
face, similar to vehicles and ships.
The main ways to reduce the fuel consumption of airplanes are laminar wings,
laminar fins, laminar nacelles, smooth surfaces, riblet skins, wingtips, and variable
112 7 Aerodynamics of Vehicles and Airplanes
smooth
surface wingtip device
laminar wing
riblets
laminar fin
integrated
design
laminar horizontal
tail fin
variable
engine installation chamber rear fuselage
PAI (CFD design)
wing profiles regulated by high capacity micro controllers, fast sensors, and high
speed actuators.
The drag depends particularly on the shape and on the surface of the airplane’s
body. Smooth laminar flow over the body produces less drag than turbulent flow.
Current aircraft design generally produces turbulent flow. Slotted airfoils or
actively heated, and cooled surfaces that encourage laminar flow are being
explored, but their benefits still need to be proven [6].
If wing-mounted propfans and un-ducted fans are increasingly used in the
future laminar flow airfoils that could tolerate the effects of propeller efflux over
the wing surface also need to be developed. Alternative mounting arrangements,
such as fuselage-mounted propfans may also be considered; see Fig. 7.3 [7].
Laminar flow without turbulence for wings, fuselage, stabilizers and nacelles is
continuously reviewed and evaluated. Besides technology, the key consideration is
the cost of laminar flow systems and their power requirements compared with
savings obtained through drag reduction.
Suboptimal integration of the engine and the nacelle which does not incorporate
the air inlet can be a source of significant drag. Effective nacelle-oriented wing and
tail constructions reduce turbulent flow areas [8]. The effect can be supported
through the use of advanced passive flow control devices, e.g., vortex generators to
7.2 Aerodynamics of Airplanes 113
Improved aerodynamic efficiency means a higher lift to drag ratio, slotted cruise
air foils and strengthened natural laminar flow [9]. New structural materials and
advanced airframe systems can contribute to the improvement; see Table 7.2.
The available width at airport gates may limit the allowable wingspan. Wingtip
devices improve the efficiency of fixed wing aircraft without extending length.
They reduce the aircraft’s drag by altering the airflow near the wingtips; see
Fig. 7.4.
Wingtips increase the efficiency of the payload of a middle range turbofan
driven airplane by 500 kg (1,102.5 lb) or by a distance of 185 km (100 nmi).
The saving of CO2 can reach up to 700 t i.e., 1.5 9 106 lb per airplane per annum.
Wingtips also improve aircraft handling and reduce the wake turbulence hazard for
the following aircraft by approximately 3% [10].
Riblets are furrows in the direction of the air flow, which are added as a film
with a thickness of less than 1 mm (0.04 in) instead of paint on the surface of
114 7 Aerodynamics of Vehicles and Airplanes
integrated winglet
reduced noise
Large ships can save energy by floating on a cushion of air [19]. This technology
needs compressed air which is pumped through holes in the bottom of the ship.
A ‘‘carpet’’ of air builds up beneath the hull, reducing friction as it passes through
the water. The air is dispersed to either side of the propeller.
Decreasing friction between the hull and the water with an air cushion can
reduce fuel consumption up to 15%. On modern ships, wave radar sensors measure
the distance from the cavity ceiling to the water surface and level sensors auto-
matically control the height of the air cushion. The heeling of the ship is also
monitored, because the greater the heel angle, the higher the probability that air
will escape.
116 7 Aerodynamics of Vehicles and Airplanes
On inland water ways, construction requirements for stability and rescue equip-
ment are adjusted to the characteristics of where the ships are going to be oper-
ating. Inland ships are smaller than sea-going ships and the resistance in shallow
water plays a decisive role in engine performance, fuel consumption and exhaust
gas emissions [20].
Inland ships have been constructed with an increasing load capacity over the
last decades. Similar to sea-going ships, this increase in size has led to higher
efficiency and to the reduction of the Specific Fuel Consumption (SCF) per DWT
capacity [21].
However, there are strict limits in inland shipping. The main limiting factors are
the resistance to the ground and to the river bank. Enlargement of inland container
ships over 3,000 DWT usually leads to a volume of more than 5,000 m3 (176,553
ft3). In special cases the flow can be optimized through the installation of an
additional propeller in the ship’s centre. Optimal flow reduces fuel consumption,
especially in the mid-speed range. Shipping up river and against the wind with
high waves at wide rivers or large lakes can increase fuel consumption by up to
10% [22].
Different rotation speeds of the propeller cause turbulence between the ship’s
hull and the banks of the water way [23]. If the distance is too small, an increasing
blocking of the feed stream to the propeller requires an increasing wave output
from the engine; see Fig. 7.5 [24].
In inland freight transportation, tug boats highly efficiently push or tow a
number of barges [25, 26]. The bow of a single ship should be as streamlined as
possible. If a tug pushes a pre-coupled barge, the bow of the tug must be rounded
by artificial designed flow plates in order to keep the turbulence at the coupling
point as small as possible; see Fig. 7.6 [27].
7.3 Hydro- and Aerodynamics of Ships 117
0
5 6 7 8 9 10 11 12 13 14 15 16
-1
velocity [km*h ]
There is still a large potential for improving the aerodynamics of vehicles, air-
planes and the common hydro- and aerodynamics of ships. Both aero- and
hydrodynamics is generally improved by smooth surfaces and compact
constructions.
118 7 Aerodynamics of Vehicles and Airplanes
There are three approaches with different reduction potentials for fuel consumption
and exhaust gas emissions:
• The use of smooth and aerodynamically optimal surfaces;
• The introduction of new technologies to achieve low air resistance; and
• Combining lightweight construction materials which have comparable or better
surface characteristics than conventional materials such as steel and aluminum.
The power to overcome air resistance increases roughly with the cube of the
speed and the energy required per unit distance is roughly proportional to the
square of the speed. The power needed to overcome the rolling resistance is also a
decisive factor, particularly at lower speeds and higher gross weights. At very low
speeds, the dominant losses are from internal friction.
Redesigning the fuselage and the wings has the greatest potential for decreasing
aerodynamic resistance. There are two main research emphases for improved
aerodynamics:
• Improvement of existing airplanes and their systems; and
• Long-term development of completely new concepts for the next generations of
commercial aircraft.
The general use of winglets can save fuel on older as well as on new aircraft
because resistance goes down and fuel consumption decreases.
Radically new concepts for commercial aircraft, like a blended wing and body
airplane would aerodynamically deliver substantially better lift, but there are also
unsolved problems which will prevent the fulfillment of the concept in the next
decades. Laminar flow can be partly realized with artificial vacuum at a very high
cost level.
Hydro- and aerodynamics plays a decisive role in the construction of ships and
determination of operating costs, similar to other sectors of transportation. Saving
fuel in ships requires:
• In the construction phase
– Increasing the vessel’s size for higher fuel efficiency;
7.4 Summary and Recommendations: Technical Results in Aero- and Hydrodynamics 119
– Improving the shape of the hull’s design for low aero- and hydrodynamic
resistance; and
– Fitting the engine and the propulsion system to the main construction and
operation condition.
• In the operation phase:
– Maintaining the cleanliness of the outer skin;
– Using even and symmetrical distribution of freight; and
– Optimizing the ship’s speed and the engine’s SFC.
These common measures significantly increase the hydro- and aerodynamic
efficiency. Since the resistance primarily influences the flow field, the question
about the optimal hull form is always connected with the propulsion, i.e., with the
complete drive. Apart from the size of the ship, optimally advanced propulsion
technologies can lower transport costs in operation, and consequently increase the
cost competitiveness of the ship.
Also, in inland shipping, the proportions between the displacement of a ship
and its power requirement improve as the ship is made larger. However, contin-
uing development will become more and more difficult due to the limited size of
inland waterways.
References
18. The tempomat: the automatic pilot for the inland shipping. http://www.technofysica.nl/
English/tempomaat.htm
19. Germanischer Lloyd (2008) Ship on a magic carpet. Environment/cover story. Nonstop. The
Magazine for Customers and Business Partners. Hamburg, pp 19–22, OE 003,
publications@gl-group.de
20. Jiang T (2001) A New method for resistance and propulsion prediction of ship performance
in shallow water. Practical design of ships and other floating structures. Elsevier Science Ltd,
pp 509–515. ISBN: 0-08-043950-012
21. Measures for the reduction of fuel consumption and CO2 emissions in inland navigation.
Central Commission for the Navigation of the Rhine. d/Workshop_CO2_Tunnelschuerze_en
22. Binnenschiff. http://www.de/wikipedia.org/wiki/Binneschiff
23. Georgakaki A, Sorenson S, Report on collected data resulting methodology for inland
shipping. ISBN: 87-7475-314-2
24. Propeller geometry. http://www.gidb.itu.edu.tr/staff/emin/Lectures/Ship_Hydro/propeller_
geometry.pdf, pp 120
25. Towboat. http://en.wikipedia.org.wiki/Towboats
26. Barge. http://en.wikipedia.org.wiki/Barge
27. Tugboat. http://en.wikipedia.org/wiki/Tugboat
28. Fluid-structure interaction during ship slamming. http://www.web.student.chalmers.se/
groups/ofw5/Presentations/KevinMakiSlidesOFW5.pdf
29. International conference on ship drag reduction (Smooth-Ships). Istanbul, 20–21 May 2010.
http://www.web.student.chalmers.se/groups/ofw5/Presentations/KevinMakiSlidesOFW5.pdf
30. Tukker J, Kuiper G.: High-speed video observation and erosive cavitation. http://www.
marin.nl/upload_mm/f/b/4/1806814280_1999999096_TVW0173.pdf
31. Bow thruster. http://en.wikipedia.org/wiki/Bow_thruster
32. Stern thruster. http://www.sternthrusters.net/
Chapter 8
Propulsion Systems
The propulsion systems generate the power and drive vehicles, airplanes, and
ships. Although the operation mediums, i.e., the road surface, the air, and the water
are physically and chemically very different, propulsion systems are similarly
structured in all means of transportation. Parts of the propulsion are often called
the transmission or drive chain.
The propulsion system contains all assemblies which are in the drive chain
between the engine and driving wheels [1]. The elements of the power propulsion
are:
• Transmission system
– Clutch gearbox, clutch, bridge, axis, drive shaft
• Wheels and tires
• Steering system
– Steering wheel, steering gearbox, rods, cruise control
• Braking system
– Brake master cylinder, power lines, brake disc
• Suspension
– Spring shock absorber, spring column.
The driving style and behavior significantly influences the propulsion
efficiency.
14
1st gear
0
0 50 100 150 200
speed [km*h-1]
Fig. 8.1 Influence of the gear choice on the fuel consumption in a mid-size car
The auxiliary equipment consists of the power steering, the brake booster, the air
conditioning system, the alternator, the windscreen wiper, the radio, the seat
heating and the air heating etc. which are usually directly powered by the engine
and significantly affect its fuel consumption.
The use of the air conditioner has the greatest effect on the fuel consumption in
a mid-size car. The amount and the energy demand of equipment is rapidly rising
in all means of transportation:
• Air conditioning system increases consumption from 0.5 to 2.5 l h-1 (from 0.13
to 0.66 gal h-1), depending upon the manufacturer and the cooling demand;
• Headlights increase consumption from 0.1 to 0.2 l h-1 (from 0.03 to 0.06
gal h-1);
• Rear window heating increases consumption from 0.1 to 0.2 l h-1 (from 0.03 to
0.06 gal h-1); and
• Other electrical consumers, e.g., windshield wipers, stereo boxes, cooling boxes,
electrical windows, electrically adjustable seats, etc., increase the fuel con-
sumption from 0.2 to 0.5 l h-1 (from 0.06 to 0.13 gal h-1) [6].
It is predicted that the air conditioning system will remain the main source of
increased consumption. Currently, it consists of a compressor directly powered by
the engine, which requires a high amount of generator capacity. In the future, it
may be that other solutions, e.g., the application of phase changing materials
(PCM) can be used for more economical and ecological air conditioning. A few
124 8 Propulsion Systems
types of PCM can be produced from biomass whose use would mean basically a
change to an environmentally friendly air conditioning technology [7].
Using headlights in the daylight requires a high energy demand. However, both
lights are necessary for safety. Nowadays, new light emitting diode (LED) tech-
nology is reducing the electrical power requirements for the car lights [8].
Accessories need energy and contribute to fuel consumption. However, they are
not considered in the measurements of the nominal consumption balance in the
Type approval as determined by the NEDC. Since all these consumers use energy
and lead to increased fuel consumption and exhaust gas emissions, they should be
considered in the estimation of future fuel consumption [9].
Propulsion in road vehicles converts the power from the engine to the tires.
A chain of sub-systems can be the source of several losses [10].
A specific problem of vehicle technology is the variety of road and driving
conditions. Driving in high mountains has different characteristics than driving in
flat regions; or driving in arctic regions differs from travelling through a desert.
Moreover, the energy dissipation in urban and in highway traffic is also very
different. On city roads, the biggest energy losses arise through the internal friction
of the engine and the transmission elements. In urban driving, apart from the kind
of engine and fuel, the efficiency of the vehicle particularly depends on its
accelerating and breaking characteristics.
The efficiency of the vehicle on the highway is largely influenced by its
aerodynamics. The fuel consumption increases with the velocity to overcome air
resistance and depends on the construction of the transmission elements, the
aerodynamic resistance of the vehicle, and the rolling resistance of the tires.
In both urban and highway driving, the dissipation of energy in the propulsion
system mainly depends on its thermal efficiency, its internal friction and the energy
demand of its auxiliary equipment. The energy losses are directly characterized by
the fuel consumption, which can be lowered to a minimum through suitable
maintenance for lower resistances and through the use of optimal driving methods.
All losses occurring while driving, flying, and shipping are converted into heat,
kinetic energy and exhaust gas emissions. Presumably, thermal efficiency can be
significantly improved in the future [11]. One of the most intensive phases of fuel
consumption is the ignition. In this phase, the heated air in the compression stroke
must ignite the injected fuel during the combustion period. The necessary
minimum ignition temperature for diesel fuel is approximately 250C (482F).
8.2 Operating Functions of the Propulsion 125
8
winter (-9 °C to -5 °C)
0
0 5 10 15 20 25 30
distance [km]
Fig. 8.2 Increased fuel consumption of a mid-size passenger car in cold weather
This temperature must be reached even with low environmental temperatures with
a cold engine.
At low temperatures, the fuel consumption of internal combustion engine
primarily increases with higher internal friction (see Fig. 8.2) [12].
Several measures are useful for high thermal efficiency during ignition:
• Using a low engine speed with optimal compression;
• Minimizing leakage losses at the piston ring between the piston and the cylinder
wall;
• Decreasing heat losses in the combustion chamber with optimal thermal
insulation;
• Applying high quality batteries to provide a high number of revolutions and high
power; and
• Using light running engine oil with low viscosity even at low temperatures.
The propulsion system of airplanes consists of the tanks, the fuel supply system,
the airframe, the nacelle and the engines. Predictions estimate a decrease in fuel
consumption by up to 25% with improved propulsion technology by the year 2050.
Significant improvements require:
• Improving the nacelle aerodynamics to reduce the load on the turbine and on the
compressor;
• Decreasing the size of the core engine;
• Increasing the thermal efficiency with higher turbine entry temperatures to
reduce air mass flow;
126 8 Propulsion Systems
Table 8.1 Mid and long term predictions for saving fuel and decreasing emissions
Technology scenario Fuel efficiency LTO NOx level
Year
2030 20–30% better than 2010 level 10–30% below current CAEP/2
2050 40–50% better than 2010 level 50–70% below current CAEP/2
The integration of engine and airframe would result in a reduction of the airplane’s
weight and the installation of specific aerodynamic elements to avoid drag.
There are complex design problems in reducing interference drag caused by
flow interactions in the region of the wing pylon. Recent improvements in mod-
eling localize airflow and bring important benefits in reduced interference drag.
However, high bypass ratio engines with a higher front diameter lead to higher air
resistance and therefore higher specific fuel consumption. Nonetheless, the aero-
dynamic disadvantages are much lower than the benefits of the new high-bypass
technology.
Propulsion and airframe integration uses a large number of subsystems to
manage the airplane in flight. Optimal integration of the airframe and engine
allows lighter construction of the fuselage, the wing and the tail units and may
contribute to a lighter undercarriage. Further system integration and extending
8.3 Propulsion of Airplanes 127
fly-by-wire control systems offer the potential for 1–3% improvement in overall
fuel efficiency including improved pollutant and noise emissions [17].
The propulsion in a ship includes all of the elements from the engine to the
propeller. The technology has been continuously and intensively changing over the
last decades. Steam engines and their connected propulsion elements have been
replaced by diesel engines or gas turbines. Highly developed technology is what
determines the current propulsion systems. They have been improved for eco-
nomic reasons and for environmental protection in the course of fulfilling the
increasing level of requirements [21].
The most complex transmission systems are used in military technology in
which the highest technology for fuel consumption, maintenance, redundancy,
efficiency and availability is required.
Propellers are ceaseless flow machines which take mechanical work and pass it to
the surrounding water in form of flow energy. As the trend moves toward larger
ships and higher velocities, the propeller’s efficiency must also be increased [22].
This requirement has led to the broad ranged application of nozzle propellers
with an inflow ring. They consist of a steel ring attached in front of the propeller,
which bundles the inflow of the water to the propeller and changes the flow
direction [23].
Inflow rings (Mewis Duct) and higher skew increase the degree of effectiveness
of the propeller and the drive performance of ships by up to 10%, primarily for
large ships (see Fig. 8.3) [24].
Besides the engine, the propeller is one of the main sources of vibrations on a
ship. In a lot of cases, it is necessary to change the geometry of the propeller to
keep the vibrations at an endurable level for the crew and for the ship construction
[25].
The number of blades in the propeller is variable. The pressure difference of the
water stream in front of and behind the propeller determines the number of blades.
Propellers can theoretically consist of one blade or of an unlimited number of
8.4 Propulsion of Ships 129
blades. In reality, there is a practical limit to seven blades that is used on the
biggest vessels such as container ships. Smaller ships have usually much fewer
numbers of blades [26].
Ventilation and cavitation appear if air is vacuumed by the water surface or
waste gases are vacuumed from the exhaust gas flow into the propeller, especially
in fast sporting boats and in small, fast marine ships with exhaust gas end pipe at a
side in the water, e.g., in stealth ships. This process reduces the performance of the
propeller, and the thrust decreases. The reason for this is the decreased boiling of
water if the pressure is low enough. In this case, steam formation starts at lower
temperatures than 100C (212F). The high propeller speed can decrease the water
pressure at the back surface of the propeller’s blade and steam bubbles can appear
which could cause mechanical damage. Whirls at the blades formed both in air and
in water lead to perforations in the propeller’s material [27].
The suitable measures against cavitation are:
• Slow steaming; and
• Sub-water coating.
New coatings such as finely powdered Polyamide-11 perform better than metals,
including stainless steel, and have exceptional resistance to cavitation erosion [28].
Ships like tugboats and icebreakers which must have a very high thrust require
a propeller with a nozzle, a large number of blades and a highly skewed design.
The Voith-Schneider propeller (VSP) can adjust the size and the direction of
thrust in a broad range without changing the speed [29].
Large ship propellers are up to 12 m in diameter (39.3 ft) and have a weight
between 80 and 120 t (176,211 and 264,317 lb). They are produced with efficient
casting methods. The application field attaches large diesel engines in the range
from 50,000 kW (67,114 HP) to 75,000 kW (100,671 HP). The technological
parameters range from a relatively low number of revolutions between 60 and
125 rpm to a directly coupled transmission without a gearbox and with high torque.
130 8 Propulsion Systems
Large propellers are usually used in very large container ships, bulk carriers and
tankers as a controllable pitch propeller [30].
Carbon fiber propellers consist of elastic carbon fiber composite material which
effectively protects against cavitation. They can be used in many types of ships of
all sizes. Carbon fiber propellers can be adapted to different loads with a wide
range of special contours and profiles. The result is higher propeller efficiency,
light weight, less vibration and less noise [31].
The linear jet is a relatively new ship propulsion system which is a highly powerful
technology and has a large thrust load. In addition, the noise of the propulsion is
reduced. It consists of a nozzle system without a ring around the propeller. On the
one side, linear jets are advantageous for high speeds of up to about 35 kn
(64.8 km h-1). On the other side, the fuel efficiency is relatively low because of
high internal resistances in the system [34].
Combinations with the Voith-Schneider propeller technology are modern
development directions [35].
Ring propellers are driving and maneuvering systems which are directly driven by
an electric motor. They usually operate as a common generator and an engine with
very large diameter, and are used to provide extremely high power, low speeds,
and high gear torque. The advantage of the large stator and rotor diameter is the
optimal maneuvering ability. The construction is mounted in a central position to
safely absorb high radial and axial forces (see Table 8.2) [36].
8.4 Propulsion of Ships 131
Starting and stopping put the highest load on the propulsion and have the highest
fuel consumption of the engine. Ship’s diesel engines are started by compressed air
because no electric motor of an acceptable size would be strong enough to move
the cylinders.
Before the start, the compressed air bottles and the air system are drained and
the pressures are checked. Starting the engine requires a 30 bar compressed air
system, i.e., 30 9 105 Pa (435 psi or 0.63 9 105 lbf ft-2). To start a large diesel
engine, the main components must be set in motion and the first strokes of the
engine with intake, compression, expansion, and exhaust must be started after the
first moving of cylinders by the air pressure [37].
The main parts of a vehicle’s propulsion system are the transmission, the braking,
the steering, the suspension elements, the wheel mounting, and the tires.
The effectiveness of propulsion is defined by the individual elements of the
whole system. While driving, the internal and the external resistances have to be
overcome by energy produced by burning of fuel in the combustion chambers.
132 8 Propulsion Systems
The main elements of an airplane’s propulsion are the engine, the fuel supply
system, the bearing and the steering elements.
The integration of the engine and airframe results in the reduction of the air-
plane’s weight and the installation of aerodynamic elements to avoid drag. New
propulsion systems have less noise and an increase in the bypass ratio from 12:1 to
15:1. These measures save fuel and lower the CO2 emissions in the fan by up to
50%. The introduction of new turbofan and turboprop engine series depends on the
economical and environmental protection requirements. The most effective
measures are the use of open rotor technology, the application of contra-rotating
turbines, and new types of the combustion chamber. Certification of new fuels can
extend current market ranges.
Future technology will use even more intelligent and more sustainable pro-
pulsion systems with large turbofans and improved geared fans. An improvement
in the future propulsion system efficiency of about 1% fuel saving per annum can
be expected.
The open rotor technology burns fuel cleaner in the combustion chamber, and
consumes 15% less fuel and produces 20 dB(A) less noise compared with the
present systems. It can go into service approximately by 2015. By 2018, light-
weight construction, integration of the engine and the nacelle, and combination of
integrated airplane and engine design will decrease fuel consumption by another
20% [39].
A ship’s propulsion system consists of the diesel engine, the steam or the gas
turbine, the diesel electric aggregate, the direct and the indirect operating trans-
mission elements, and the propeller.
Slower ships use a two-stroke or a four-stroke diesel engine and faster ships use
gas turbines as a propulsion. Electric motors and connected transmission systems
are common in submarines. Fuel cells and nuclear reactors are employed to propel
some warships and icebreakers.
8.5 Summary and Recommendations: Propulsion Systems 133
Fast running diesel–electric systems are gaining more and more importance,
although they have a higher SFC than slow running two-stroke diesel engines.
Their advantage is the wide ranged variability in the construction, the relative
freedom for increasing and decreasing the number of aggregates, and the low
concentration of pollutants in the exhaust gases. The construction with diesel–
electric system makes it possible to optimize the external aerodynamic design and
internal space construction of the ship, because they are small and systems can be
decentrally placed in the hull, contrary to the high pace demand of two-stroke
crosshead diesel engines.
There are many variations of propeller systems, including twin and contra-
rotating, variable pitch, and nozzle-style propellers. Smaller vessels tend to use a
single propeller. Aircraft carriers use up to four propellers, supplemented by bow-
thrusters and stern-thrusters.
Apart from the number of propellers, power is transmitted from the engine to
the propeller by a propeller shaft, which may or may not be connected to a
gearbox. There is a growing tendency in the use of large propellers, carbon fiber
strengthened plastic propellers, pod propulsion systems, linear jets, and ring
propellers.
References
1. Powertrain. http://en.wikipedia.org/wik/Powertrain
2. Guzella L, Sciarrette A (2007) Vehicle propulsion system, 6th edn. Springer. http://
www.idsc.ethz.ch/about/Books/Teaser.pdf
3. Physics in an automotive engine. http://www.mb-soft.com/public2/engine.html
4. Rev matching and gear shifting. http://www.drivingfast.net/car-control/rev-
matching.htm#axzz1aNewsm4t
5. Schallaböck KO, Fischedick M, Brouns B, Luhmann HJ, Merten F, Ott HE, Patowsky A,
Venjacob J, Klimawirksame Emissionen des PKW-Verkehrs. Wuppertal Institut für Klima,
Umwelt und Energie. ISBN-10: 3-929944-72-3
6. Apparatus for controlling auxiliary equipment driven by an internal combustion engine.
Patent 5924406. http://www.patentgenius.com/patent/5924406.html
7. Phase change material. http://en.wikipedia.org/wiki/Phase-change_material
8. Light-emitting diodes. http://en.wikipedia.org/wiki/Light-emitting_diode
9. Edinger R, Kraul S (2003) Sustainable mobility: renewable energies for powering fuel cell
vehicles. Greenwood Publishing Group, Consumption and Emissions, pp 18. ISBN-10:
1-56720-484-8
10. Fuel economy maximizing behaviors. http://en.wikipedia.org/wiki/Fuel_economy-maximizing_
behaviors
11. Thermal efficiency. http://en.wikipedia.org/wiki/Thermal_efficiency
12. Volkswagen: Save as you drive. March 2009. Article No. 960.1606.02.18
13. Hünecke K (2008) Die Technik des modernen Verkehrsflugzeuges, 1st edn. Motorbuch
Verlag, Stuttgart. ISBN-13: 9789-3-613-02895-8
14. Leiser, weiter, sparsamer. Luftfahrt. Der Spiegel Hamburg. 02/2009. pp 113–114. http://
www.spiegel.de
134 8 Propulsion Systems
15. Potential impact of aircraft technology advances on future CO2 and NOx emissions. 19 May
1998. NASA Research Workshop II. http://www.aeronautics.nasa.gov/events/encompat/
gynnppt.pdf
16. Engine–airframe integration during conceptual design for military application. http://
www.idearesearch.in/Papers/VivekSanghi_EngineCycleSelection.pdf
17. Airframe and systems design. http://www.aero.cz/en/airframe-and-systems-design.html
18. Jet engine test cells-emission and control measures: Phase 2. EPA 340/1-78-001b. April
1978. Washington. http://www.nepis.epa.gov
19. New engines give older jets new life, but values equation is still a challenge. http://
www.avbuyer.com/articles/PrintDetail.asp?Id=1417
20. Simple thermodynamics of jet engines. http://www.stat.physik.uni-potsdam.de/*pikovsky/
teaching/stud_seminar/jet_engine.pdf
21. Marine propulsion. http://en.ewikipedia.org/wiki/Marine_propulsion
22. Propeller. http://de.wikipedia.org/wiki/propeller
23. Perfekte propeller. http://www.dmkn.de/downloads/2f/c7/i_file_50119/PerfektePropeller.pdf
24. Zöllner J. (2003) Vortriebstechnische Entwicklungen in der Binnenschifffahrt. 24. Duisburger
Kolloquium Schiffstechnik/Meerestechnik. Universität Duisburg-Essen Institut für
Schiffstechnik und Transportsysteme. 15–16 May, pp 134
25. Propeller vibration. http://www.epi-eng.com/propeller_technology/propeller_vibration_
issues.htm
26. Selecting an equivalent multi-blade propeller. http://www.mh-aerotools.de/airfoils/
propuls2.htm
27. Pumps & systems. State of the pump industry 2005. http://www.arkema.com/pdf/EN/
products/technical_polymers/rilsan_fine_powders/pumps.and.systems.reprint.1.19.05.pdf
28. Cavitation erosion study of metals and coatings—including polyamide-11 powder coatings.
Technical polymers R&D USA-France
29. Voith-Schneider Antrieb. http://de.wikipedia.org/wiki/Voith-Schneider-Antrieb
30. Technology guidelines for efficiency design and operation of ship propulsion. http://
www.propellerpages.com/downloads/
Technology_guidelines_for_efficient_design_and_operation_of_ship_propulsors.pdf
31. Fuel saver/carbon fibre props. http://www.compositecarbonfiberprop.com/
32. Azimuth thruster. http://en.wikipedia.org/wiki/Azimuth_thruster
33. Pod-drive for ships (electric motor) AZIPOD. ABB. http://www.nauticexpo.com/…/pod-
drives.-for-ship…
34. First Voith water jet: Jet propulsion system. http://www.porttechnology.org/technical_papers/
first_voith_water_jet_jet_propulsion_system
35. Untersuchung tiefgetauchter Waterjet. http://www.m-schmiechen.homepage.t-online.de/
HomepageClassic01/prp_linf.pd
36. Advanced technology of propeller shaft stern tube seal. http://www.kemel.com/product/pdf/
SNAMEAirSealFinal07_30_03.pdf
37. Procedure for starting and stopping generators on a ship. http://www.marineinsight.com/tech/
proceduresmaintenance/procedure-for-starting-and-stopping-generators-on-a-ship/
38. Ceuca E, The 42 volt power net architecture standards. http://www.uab.ro/auajournal/acta2/
Articol%20Ceuca%20E.pdf
39. GE and NASA to test open rotor jet engine system. http://www.uab.ro/auajournal/acta2/
Articol%20Ceuca%20E.pdf
Chapter 9
Vehicle Engines
Internal combustion engines use fossil fuels. They determine the typical con-
struction of transportation means by transforming the chemical energy in fuel into
mechanical power. The principle is common in vehicles, airplanes, ships and
portable machines (see Table 9.1) [1].
In construction machines and tractors, internal combustion engines are
advantageous since they can provide a high power-to-weight ratio usually with
excellent fuel energy density. Gas turbines are used where very high power is
required, such as in generators in the energy industry, in jet engines of airplanes
and in the auxiliary equipment of ships.
Performance standards and requirements for internal combustion engines have
intensively increased over the last decades (see Fig. 9.1).
extension of preventive
inspection and maintenance micro sensors
measures and actuators
engine
data transmission on-board monitoring
to a central control
high level of safety on-board diagnosis
gasoline engines
fuel
diesel combustion engine electric engine
gas
CNG spark self lead- nickel- lithium-
ignition ignition acid cadmium ion
LNG
hybrid engine
LPG
.
Besides combustion engines, more and more electric engines are being used in
transportation.
Figure 9.2 shows the technical variants of the basic principle of operation [6].
The most important vehicle types in transportation, depending on engine type, are:
• Combustion engine vehicles (CEV);
• Plug-in hybrid engine vehicles which are the combination of a CE and a battery
or a fuel cell driven electric engine (EE);
9.1 Principles of Operation 137
Most vehicles are designed with a spark or a self-ignition engine. Diesel power is
increasing for passenger as well as freight transportation. The main properties of
spark ignition engine types are presented in Table 9.2 [7].
138 9 Vehicle Engines
A spark ignition engine takes in a mixture of air and fuel and compresses it. The
fuel is usually gasoline, but other hydrocarbons such as LPG or CNG are also
becoming more and more common. It uses a spark plug to ignite the mixture when
it is compressed by the piston head in the cylinders.
The efficiency of a spark ignition engine mainly depends on its construction and
operation (see Table 9.3).
Construction elements determine the design, the size, and the frame conditions of
operations (see Table 9.4).
In the past, self ignition engines were generally heavier and noisier than spark
ignition engines. The newest models are small and of a very similar size to a spark
ignition engine in the same performance class. On the other side, self ignition
engines are more efficient in fuel consumption and more powerful at lower speeds
than spark ignition engines, but differences are disappearing [22].
In Europe, sophisticated cars with self-ignition engine have about a 40% share
of the market. The portion in the USA and in other regions of the world is lower
but it is continuously increasing [23]. Most self-ignition engines operate in road
vehicles, locomotives, construction machinery, tractors, buses, and ships.
Table 9.4 Impact of construction on fuel consumption and exhaust gas emissions
Construction parameters Physical properties
Combustion chamber profile A compact combustion chamber can save engine volume. However, low cracks and piston strokes increase NOx
emissions, reduces flame quenching, and the cold wall could lead to the expiration of the flame [8]
Combustion chamber design In spark ignition engines, the combustion chamber is predominantly in the cylinder head in contrast to self ignition
engines with direct injection, by which the piston serves for the admission into the combustion chamber [9]. The
pistons of spark ignition engines possess either a light hollow or they are flat. In the multi valve engine an inlet
channel can be constructed as a swirl channel which can increase the mixture preparation in the lower partial-load
area especially with a low mass flow. The second channel, which operates at a higher load and higher number of
revolutions, serves as a filling channel [10]
Compression ratio The compression ratio can be extremely high in the full load range. In a spark ignition engine, the limit is given by the
knocking characteristics. The NOx emissions increase with extremely high compression ratios. Leaner burning with a
higher Lambda number can decrease NOx emissions. Thermal efficiency in spark ignition engines is between 0.35 and
0.45 on average and in self ignition engines between 0.50 and 0.60, depending on construction [11]
Spark plug position The situation of the ignition plug, the number of valves, and the conception of the valve impulse, e.g., a variable valve
impulse influences the fuel consumption and the exhaust gas emissions. Four or more valves allow the spark plug
to be centrally positioned [12]
9.2 Operation of Spark and Self Ignition Engines
Ignition point Fuel consumption and exhaust gas emissions can be influenced by the ignition energy, and by the shape and position
of the spark plug [13]. Late ignition points result in increasing exhaust gas temperatures, which produce favorable
conditions for post reactions of HCs and CO. Additionally, late ignition increases fuel consumption. However, it
shortens the warmup phase of the engine and optimizes the starting characteristics of the catalyst
Idle stroke bore relationship to The longer the stroke of an engine, the smaller the HC and CO emissions and the partial-load fuel consumption.
cylinder volume However, the size of the idle stroke bore relationship to the cylinder volume is not freely dimensionable, because
criteria such as the mass forces, combustion chamber design, task of the construction, existing manufacturing
plants, etc., usually permit only a closed range for the application [14]
The long stroke engine offers a great potential for the improvement of the efficiency degree, in particular in four-
valve combustion chambers by higher compression ratios [15]
139
Table 9.5 Impact of operation mode on fuel consumption and emissions
140
Table 9.6 Main construction and operation parameters of self ignition engines
Construction parameters Operation parameters
Combustion chamber Valve propulsion
Cylinder block and head Mixture formation
Pistons and rings Pre-heating
Crank shaft Common Rail
Cam shaft Sealing
Con rod Cooling
Cocks Lubrication
Air and oil containing parts Torque
Fuel filter Performance
Intake air tube and exhaust gas pipe
7
1
2
8
3
4 6
9
11
10 5 15
14
12
13
1. camshaft, 2. valve, 3, pistons, 4. injection system, 5. cylinder, 6. exhaust gas feed back,
7. intake pipe, 8. exhaust gas turbocharger, 9. exhaust gas tube, 10. cooling system,
11. piston road, 12. lubrication system, 13. engine block, 14. crankshaft, 15. flywheel
Similar to spark ignition technology, the SFC and the exhaust gas emissions of
the self ignition engine depend on the construction and operation parameters (see
Table 9.6).
Table 9.7 Main construction parameters in the self-ignition engine
142
be installed from the tank to the high pressure pump [41]. Apart from weight reduction, this change should also lead to increased
service life without corrosion
Intake air tube and exhaust Intake tubes and bend pipes are made of plastics. In order to minimize noise the interior flow is optimized by vibration-free mountings [42].
gas pipe Exhaust gas ducts and bend pipes are no longer designed from cast iron but more from sheet metal [43]. The heat insulation of
neighboring components gain in importance. Auxiliary elements in the exhaust duct are the additional exhaust gas control valve, the
compressor bypass for switching, the turbocharger, and the exhaust gate flap which supports the engine’s brake. Closing the exhaust gas
flap produces back pressure in the exhaust gas which retards the engine. Braking efficiency can be improved with continuous
Vehicle Engines
applications that must be protected against high temperatures in the combustion system should use a lower pressure than in the
past by approximately 800 9 105 Pa (11,604 psi, i.e., 16.71 9 105 lbf ft-2). However, tendencies show in the direction of higher
pressures and lower drop diameters. Radial piston pumps should be used for higher efficiency, longer life span, lower weight, and
reduced noise [49]
Sealing system Cylinder head sealing must be adapted to the increasing pressures [50]. The materials of the cylinder head define their use, which
greatly influences the life span of the engine. Wave can be sealed with radial sealing. Crankshaft seals have to cope with high
pressures and temperatures
Cooling system The temperature of the self ignition engine is regulated by two different cooling systems [51]. Wet cylinder barrels and bored or
calibrated ducts are used for interior engine cooling. Engine temperature is regulated by ambient air. Today, cooling fans with a
special coupling are used which turn on in response to the engine temperature. The precise regulation is important because large
fans in modern heavy commercial motor vehicles use a high proportion of the engine power, between 15 and 21 kW (20 and 28
HP). Future engines will work with higher combustion temperatures and therefore they must be intensively cooled
(continued)
143
Table 9.8 (continued)
144
Fig. 9.4 Cooling and lubricating system of self ignition combustion engines
Self ignition engines are usually built in a design with ‘‘in-line’’ and ‘‘V’’ engine
form [25]. Friction losses in the construction are shared in the transmission by
32%, in the oil pump by 10%, in the valves by 8%, and in the piston rings by
approximately 50%.
Figure 9.3 presents the main elements of a self ignition engine [26].
The main construction elements and their influence on fuel combustion and
exhaust gas emissions are presented in Table 9.7.
Table 9.8 presents the impact of main operation modes on the fuel consumption
and exhaust gas emissions of self ignition engines.
Figure 9.4 shows the common operation of cooling and lubricating system of
self ignition engines.
There are four- and two-stroke engines. The combustion cycle of four-stroke
engines consists of the intake, the compression, the expansion, and the exhaust.
A complete operating cycle of the engine requires two crankshaft revolutions.
Four-stroke engines have one inlet and one outlet valve per cylinder for the gas
exchange.
Key parts of the four-stroke engine are the crankshaft, the connecting rod, one
or more camshafts and the valves.
In a two-stroke engine, two piston strokes and only one crankshaft revolution
are needed for one combustion cycle. The first cycle covers the intake and the
compression; the second cycle does the expansion and moves the exhaust gases
146 9 Vehicle Engines
from the combustion process. The intake and the exhaust of the combustion gasses
can be moved only by the motion of the piston because of high flow inertness.
Two-stroke engines require other forces such as an extra pressure gradient
produced by a flushing blower which flushes the cylinder from the air intake to the
exhaust gas side. In four-stroke spark ignition engines, the blower can be an
internal system which is constructed by the crankcase volume change; in two-
stroke self-ignition engines, an external device, e.g., a Roots supercharger is used
for positive displacement [57].
There are still potential for improvement both for the spark and the self ignition
engine.
References
The most important types of aircraft engines are the turbojet, the turboprop, the
turbofan and the turboshaft engine type. Turbojet is the oldest kind of general
purpose jet engine. Currently, the most important system is the turbofan tech-
nology. The main parameters of types are presented in Table 10.1.
Combinations of gas turbine and propeller have a high efficiency [7]. Thermal
efficiency can be increased by minimizing heat losses. Consequently, net thrust
will increase, while SFC, i.e., fuel flow per net thrust decreases. Currently,
improved combustion chamber design, highly resistant turbine materials, and an
optimal vane and blade cooling are required to cope with higher temperatures in
the combustion chamber and in the turbine inlet. The best SFC values are reached
by contra-rotating, unducted turbofan engines [8].
Turbofans optimally operate in the range from 400 to 2,000 km h-1 (from 250
to 1,300 mph) depending on the net thrust and the intake air flow. They are
classified into two categories:
• Low bypass ratio; and
• High bypass ratio.
In a low bypass turbofan, only a small amount of air passes through the fan
ducts. The fan has a small diameter. The low bypass turbofan is always constructed
in a very compact form. In high bypass turbofans the fan is larger to force a higher
volume of air through the ducts; the thrust is greater, and the thrust specific
consumption is lower than in low bypass turbofans [9].
10.1
1 2 3 4 5 6
Development is moving toward higher bypass ratios, larger fan diameters, higher
masses, higher thrusts, and lower fuel consumption rates.
Currently, thrust and speed are presenting continuously increasing and SFC
decreasing tendencies in aviation (see Table 10.2) [10].
The production costs of jet engines are increasing. The price range of modern
turbofan engines is from €10 to 30 million, i.e., from US $14.3 to 43.9 million.
Increasing the bypass and pressure ratio without increasing the fan diameter
means less core flow which increases the temperature at the turbine inlet [11, 12].
The control of the combustion chamber needs additional micro sensors for burning
and exhaust gas products. Self-Diagnosis will become more important since
modern jet engines are constructed with higher loads and higher durability.
In the combustion chamber the burning process produces high pressures and high
temperatures according to the mixture conditions. Most combustion chambers
operate with an air surplus in the burner can [13]. The mixture in the combustion
10.3 Construction of the Combustion Chamber 153
zone can be influenced by the fuel to air relationship, i.e., the Lambda number.
At lower engine speeds, the relationship is approximately k = 1.3, while cruising
the mixture has a Lambda number of around k = 1.6. The mixture of fuel and air
and the combustion process in a single combustion chamber are illustrated in
Fig. 10.2 [14].
The main combustion chamber type is the ring combustor. The compressor
pushes the air flow to the combustion chamber at a speed of approximately
150 m s-1 (335.61 mph), in which the kerosene and air mixture has a combustion
speed between 25 and 30 m s-1 (55.93 and 67.12 mph). For efficient combustion,
the fuel and air mixture must remain in the combustion zone from 0.004 to 0.008 s.
This time interval is long enough to completely burn the fuel. The fuel drops must
be gasified, mixed with air, and heated to the ignition temperature. The combustion
temperature in the burning zone is approximately 2,573C (4,663F) [15].
Higher temperature and pressure increases the damage in the combustion
chamber which requires more maintenance and repairs. Therefore, improved
cooling technology in the combustion chamber and in the exhaust gas pipe are
required which contributes to higher efficiency and to lower costs [16].
The optimal operation of the combustion chamber of a jet engine’s gas turbine
must work with:
• Stable, vibration-free combustion process on the ground and in the air;
• Optimal thinning of the combustion gases at a temperature which does not lead
to overheating of the first turbine stage;
• Efficient burning fuel and efficient releasing the energy contained in the fuel;
• Low pressure loss which could be the result of increased friction;
• Simple maintenance and repair; and
• High durability of all elements [17].
These facts are the preconditions for optimal operation and must be inspected
and maintained during the whole life time of the engine.
In the future, the following goals will be more important for the further
development of combustion chamber technology:
• Improving the construction between the compressor and the turbine to save
space and weight;
• Maintaining a more uniform temperature and pressure distribution in the exhaust
cross-section; and
• Optimizing ignition [18].
In aviation, the level of unburned CO and HC from engines is very low and the
amount of visible smoke is under control currently. The exhaust gases contain
more CO and HC only during idling because of the low air and fuel throughput, the
154 10 Airplane Engines
CO
1.0
CnHm
0.1
300 400 600 800 1 000
temperature [K]
low pressure and the low temperature in the combustion chamber which leads to
the production of unburned substances (see Fig. 10.3) [19].
The Bypass Pressure Ratio (BPR) means the rate of air mass flow between the
engine bypass and the engine core. Increasing the BPR has limits in turbofans
because higher temperatures at the turbine rotor and compressor inlet produce
material problems [20]. In this section, improved vane and blade cooling and high
efficient compressors with heat resistant materials, e.g., plasma spray ceramic
protective layers and thermal barrier coatings on the surface (ZrO2Y2O3), are still
needed [21].
Turbofans contain two mechanically independent rotors, one inside the other. The
fan, the low pressure compressor and the low pressure turbine are installed on the
inner rotor, called the N1 rotor. The outer rotor, called N2, holds the high pressure
compressor and turbine. It includes an intake valve to pass fuel to the engine, a
pump to increase fuel pressure, coolers, heaters and filters for the fuel, a second
pump to further raise the fuel pressure, a shut-off valve in front of the combustion
chamber and a fuel flow meter providing flow information to FMS.
Turbofans contain tubes for analyzing rotation speeds N1 and N2, Exhaust Gas
Temperature (EGT), fuel pressure, fuel temperature and fuel flow in the pipes, fuel
quantity in the tanks and filter saturation. The electronic engine control senses the
position of the thrust lever, compares the actual with the target N1. According to
the aircraft configuration and altitude, it automatically sets the engine thrust by
adjusting the fuel flow to achieve the target N1, commanded by the auto throttle
system or by the pilot.
Measuring points in the combustion and exhaust gas system are presented in
Fig. 10.4.
10.5 Measurement in Turbofan Engines 155
temperature [°C]
30 126 580 1 400 875 (max 950) 575
pressure [kPa]
101.4 235.8 201.3 284.1 234.4 162.1
1 2 3 4 5 6 7
Fig. 10.4 Temperature and pressure at the main measuring points in the engine type CF6-50 E/C 2
Table 10.3 shows the main operation parameters. Fuel flow in engines of the
1990s has been approximately 2.5–2.6 kg s-1 (5.5–5.7 lb) [22]. The ratio of fuel
flow in jet engines has been continuously decreasing in the last years. Modern
engines consume less than 2.0 kg s-1 (4.4 lb s-1) of fuel. The TSFC attaches ranges
from approximately 17.1 g (kN s)-1, i.e., 0.605 lb (lbf h)-1 to 8.696 g (kN s)-1,
i.e., 0.307 lb (lbf h)-1.
156 10 Airplane Engines
The first fuel-efficient engines with higher bypass ratios were introduced in the
1970s and 1980s. They reduced HC and CO emissions but increased the NO and
NO2 output. In contrast to unburned substances, NO and NO2 concentrations are
higher in full load intervals because of the higher air and fuel throughput, and the
higher pressure and temperature. The aim is to reduce NO and NO2 levels by 50%
of the current level within 5–10 years.
The new approach involves improving the uniformity of fuel injection, mixing
fuel and air, and reducing emissions. NOx levels may be reduced to 50–70% of the
present amount by using multiple combustion zones in radial and axial configu-
rations, which permit optimal local temperatures and burning times in the
combustor.
High bypass turbofan engines are generally quieter than the earlier low bypass
engines. Using multi-stage fans significantly increases thrust and velocity of
exhaust gases. The combination of a higher BPR and a higher turbine inlet tem-
perature further improves thermal efficiency and lowers SFC.
Both economic and safety considerations limit the installation of new com-
bustor designs to old engines. A new construction is often introduced as a package
that includes modifications to the combustion chamber, to the fuel nozzles, and to
the engine control. Positive steps must prevent intermixing of new and old com-
ponents during maintenance. Of course, other requirements such as better fuel
consumption, lower peak cycle temperatures, reduced NO, NO2, and particle
emissions, and high durability with low costs must also be balanced if combustion
technology is retrofitted.
Micro sensors in the combustion chamber could become important in the future
jet engine technology because they could add additional signals to the current
sensor technology and control the first deteriorations in the burning process. Self
Diagnosis can be a further developed stage in addition to recent Emission Index
technology.
References
10. Schubgiganten Top 10 (2010) Flugrevue. Das Luft- und Raumfahrtmagazin. pp 82–87. ISSN:
0015-4547. http://www.flugrevue.de
11. Bypass ratio. http://en.wikipedia.org/wiki/Bypass_ratio
12. Overall pressure ratio. http://en.wikipedia.org/wiki/Overall_pressure-ratio
13. Gas turbines in simple cycle & combined cycle applications. http://www.netl.doe.gov/
technologies/coalpower/turbines/refshelf/handbook/1.1.pdf
14. Aircraft technical: The jet engine components. http://www.pilotfriend.com/training/
flight_training/tech/jet_engine_components.htm
15. Real-time measurement of jet aircraft engine exhaust. http://www.patarnott.com/pdf/
JetPA.pdf
16. Neue Brennkammer (2010) Flugrevue. Das Luft- und Raumfahrtmagazin. pp 88. ISSN:
0015-4547. http://www.flugrevue.de
17. Neue Klasse (2009) Business-Jet-Triebwerke auf der Suche nach Anwendungen. Flugrevue,
Das Luft- und Raumfahrtmagazin, pp 66–67. ISSN: 0015-4547. http://www.flugrevue.de
18. Brennkammer. http://www.techniklexikon.net.d/brennkammer.htm
19. Raipdal K Aircraft emissions. http://www.ipcc-nggip.iges.or.jp/public/gp/bgp/2_5_Aircraft.
pdf
20. Safeguarding our atmosphere. http://www.nasa.gov/centers/glenn/about/fs10grc.html
21. Micro-laminated (ZrO2–Y2O3)/(Al2O3–Y2O3) coatings on Fe–25Cr alloy and their high
temperature oxidation resistance. http://adsabs.harvard.edu/abs/2007SRL....14..499Y
22. Turbofan. http://en.wikipedia.org/wiki/Turbofan
Chapter 11
Marine Diesel Engines
Marine diesel engines are very similar to the self-ignition engines in heavy-duty
vehicles, but they are generally larger, more complex, and operate with higher
efficiency. About 75% of all marine diesel engines are four-stroke engines; how-
ever, 75% of the installed power is produced by two-stroke engines. Four-stroke
marine diesel engines are gaining importance not only in inland, but also in marine
shipping, primarily in smaller container and bulk carrier ships. Fuel consumption
and exhaust gas emissions of ship engines depend not only on the principle of
operation, but also on the type, the size, the power, the load, the speed, etc. [1].
On the one side, fuel saving and exhaust gas after treatment technology in ship-
ping will gain more importance in the next years because fleet management will
focus on fuel and exhaust gas emission saving. On the other side, fuel saving is
directly combined with environment and climate protection. Higher costs of fuel
intensively support developing fuel saving technologies. Fuel saving also contributes
to innovations in climate protection technology and to development in legislation [2].
Modern marine diesel engines with direct injection have a maximum brake effi-
ciency of 40–43%. Further improvement of the direct injection technology is
possible. Although improvements will continuously go on, they will be carried out
in small steps.
Retrofitting older engines has often high costs, particularly in larger ships. This
is one of the reasons why quality of retrofitting measures must always have a high
level. The attempts to improve engines include:
• Controlling and reducing the friction of the main and auxiliary parts with
lubrication;
178
20
177
179
181
pressure [bar]
15 188
191 SFC
-1
196 [g*kWh ]
10 201
207
213
219
5
400 500 600
number of revolutions [1*min -1]
6 -1
specific heating value of fuel 42.7*10 J*kg
Fig. 11.1 SFC of a medium speed marine diesel engine in fuel consumption diagram
• Reducing the heat losses of the cylinder walls by optimizing the thermal insu-
lation of all heat parts, particularly near the cylinders;
• Introducing variable swirl with the injection of the fuel;
• Using variable intake air flow;
• Introducing a variable compression ratio using specific high dynamic pressure
and temperature sensor and actuator technology;
• Using SCR catalyst and particle filters in the exhaust gas after treatment system
additionally to recent silencer technology and occasionally in addition to the
exhaust gas boiler technology; and
• Applying gas concentration and particle sensors to monitor the catalyst and the
particle filter [3].
All parts of the engine, the turbocharger, the compressor and the exhaust gas
after treatment system must be optimized to reduce fuel consumption and emis-
sions. The use of electric turbochargers is possible, but electric motors are great
and have disadvantageous high inertia when starting.
The SFC firstly depends on the number of revolutions and the exhaust gas
pressure. The piston-stroke to bore ratio, the size and the form of the valve cross
section and the valve timing additionally influences the SFC [4].
The SFC can be estimated, depending on the number of revolutions and the
Break Mean Effective Pressure (BMEP), with fuel consumption diagrams drawn
on paper or on computer (see Fig. 11.1) [5].
Changes in the SFC can be exactly measured with analyzing CO2, unburned
hydrocarbons and carbon monoxide concentrations in the exhaust gas. The pre-
conditions for successful analysis are suitable micro measurement devices appli-
cable in ships, which can analyze the concentration with the required accuracy and
durability [6].
11.1 Fuel Consumption in Marine Diesel Engines 161
Table 11.1 Characteristics of large, slow speed, two stroke marine diesel engine
Engine Physical properties
characteristics
Operation Two-stroke crosshead engines have piston diameters from 350 mm (13.82 in)
parameters to 1,080 mm (42.66 in) and strokes of up to 3,200 mm (126.4 in). The
average cylinder volume is 600–650 l (21.2–23.0 ft3) with a middle
cylinder bore of 600 mm (23.6 in). The piston speed is between 4.0 m s-1
and 6.0 m s-1, i.e. between 13.2 and 19.7 ft s-1. Fast engines run at about
8.0 m s-1 (26.2 ft s-1). The ignition pressure ranges from 140 9 105 Pa
to 160 9 105 Pa, i.e., from 2.92 9 105 lbf ft-2 to 3.34 9 105 lbf ft-2 or
from 2,030 to 2,320 psi [9]
Dimensions Currently, the dimensions are up to 29 9 15.5 9 11.5 m or 95.1 9 50.8 9
37.7 ft, i.e., length x width x height and the weight is up to 2,300 t
(5,066,079 lb) (Wärtsila 14RT-flex96C). The wave output ranges up to
84,420 kW (114 811 HP), (Wärtsila RT-flex/RTA96C) at 102 rpm.
However, development is very fast and new engines will be larger and
heavier [10]
Control system Fully electronic engine control makes it possible to separately regulate the
fuel injection, the exhaust-valve opening and closing, the cylinder
lubrication and the compressed air starting the engine operation after
interruption. Sensors monitor pressures, temperatures, number of
revolutions and other fuel management parameters, such as fuel
consumption [11]
Fuel Two-stroke marine diesel engines can burn a variety of fuels, even biogenic
and synthetic fuels or CNG and hydrogen [12]
Efficiency The two-stroke engine theoretically would produce twice the power of an
equal sized four-stroke engine. However, due to losses from the lower
operating efficiency only approximately 60% of the theoretical efficiency
can be reached. Two-stroke engines guarantee low fuel consumption and
high reliability, optimal durability and extremely long lifespan also with
low viscosity and variable quality of fuels [13]
Engine operation mainly depends on the principle of operation, the size and the
number of revolutions, often called the speed of the engine. There are slow,
medium, and high speed diesel engines.
162 11 Marine Diesel Engines
50
40
two-stroke
concentration [%]
20
change of NOx
50
10
0
-10
four-stroke
-20
-30
-40
-8 -5 -4 -2 0 2 4 6 8 10
change of fuel consumption [%]
Fig. 11.2 Impact of changing fuel consumption on NOx emissions at constant rpm
Slow speed, high capacity marine diesel engines are the largest engines in the
world which operate with a crosshead principle at a maximum of 300 rpm. Most
large two-stroke, slow speed diesel engines operate below 120 rpm, even between
60 and 70 rpm. Two-stroke marine diesel engines have the best SFC among
internal combustion engines. Their construction and operational characteristics are
presented in Table 11.1 [8].
Slow speed marine diesel engines usually work with gate, valve, and port
control as well as with a combination of them. In the largest engines only the valve
and the port control are used.
NOx emissions are directly related to the combustion temperature. Decreasing the
amount of fuel injected into the combustion chamber usually requires more intensive
mixing which increases the temperature in the burning zone and lead to locally higher
NOx emissions at a constant number of revolutions (see Fig. 11.2).
Medium speed marine diesel engines are widely used as main and auxiliary
engines. They operate on diesel fuel or heavy fuel oil by direct injection in the
same manner as low speed engines. There are natural gas fueled versions, which
operate on the Otto cycle and also dual fuel versions (Table 11.2) [14].
High speed marine diesel engines are usually used to provide high specific power,
low weight, and small volume. They are special engines and have a maximum
11.2 Engine Operation 163
operating engine speed between 900 and 2,300 rpm. Similar to the medium speed
engine, the ignition pressure is approximately 200 9 105 Pa, i.e., 4.18 9 105
lbf ft-2 or 2,901 psi [15].
There is no sharp differentiation between medium and high speed marine diesel
engine (see Table 11.3).
Medium speed four-stroke marine engines are particularly advantageous at
lower speeds and lower partial loads. High speed four-stroke engines are used on
sport and lifeboats, and on specific smaller ships.
Gas turbines are used on ferries and navy ships, and provide higher speeds and
power ranges. They have the highest SFC under marine engines [16].
Charging any diesel engine with air increases its performance without increasing
its speed by more than 50%. The efficiency of a turbocharger directly influences
164 11 Marine Diesel Engines
the fuel consumption and exhaust gas emissions of the engine. Improving the
turbocharger’s efficiency from 60–70% decreases fuel consumption up to 2% [17].
Two-stroke engines must operate with a constant pressure in all cylinders and
the charging air has to be equally distributed to all cylinders. Differences in the
operation significantly influence the flow resistance. The result could be a
lengthways flush with small air throughput in the cylinders. Precisely, regulating
charging air supports the changing exhaust gases in the cylinders. The charging
process can be further optimized by using additional compressors, e.g., electric
boosters [18].
A ship can gain or lose efficiency as the weather changes. The most important
factors influencing fuel consumption and emissions are:
• Ambient air temperature;
• Charging air temperature; and
• Exhaust gas back pressure (see Table 11.4).
Figure 11.3 shows the reaction of the engine to increased exhaust gas counter
pressure.
11.3 Main Operation Characteristics of Marine Diesel Engines 165
1.1
exhaust gas temperature
variation related
to output value
before turbine
fuel consumption
1.0 output (constant)
charging pressure
air throughput
0.9
0.8
0 10 20 30 40 50
pressure of exhaust gas before turbine [mbar]
Fig. 11.3 Impact of exhaust gas counter pressure on engine service data
Marine diesel engines need reserve power to compensate for increases in resis-
tance of the ship’s hull and decreased efficiency of the engine caused by wear and
contamination. Minimum efficiency reserves must be 10–15%.
The engine might only keep 75–80% of its theoretical efficiency measured at
the dockyard under test drive conditions. The reserve efficiency of 20–25% can
cover the resistance increases and the efficiency losses without reducing the ship’s
speed at sea or at inland water ways.
In bad weather, speed has to be decreased depending on the power of the waves
and wind. The captain has to alter course according to the direction of the waves
and the wind to save fuel and maintain the ship at slower speeds. Bad weather
increases the temperature and the counter pressure in the exhaust gas in all relevant
elements back to the outlet valves. Sailing in bad weather for a long time can
increase the risks of overheating the engine and of high-temperature corrosion in
the exhaust gas after treatment system [22].
Although light weight materials are gaining importance in the construction of all
means of transportation, many different and non-replaceable conventional mate-
rials such as steel and aluminum are still used in the production of marine diesel
engines.
The development of engines with rising power increases the stresses on the valves.
The temperature of the inlet valves is 500–550C (932 – 1,022F) because of the
cooling effect of the fuel and air mixture. Outlet valves may reach operating
temperatures of about 850C (1,562F). For this task, Hardened Alloy Ferritic-
Pearlitic (AFP) such as martensitic-carbidic and austenitic-carbidic steels are being
developed with higher strength [33].
The advantages of aluminum cast products are its light weight and precise
tolerances. Aluminum alloys can be used for mechanical parts with small internal
diameters, e.g., for cylinder elements with small oil channels or for pistons with
small holes. The compressor wheels of the Exhaust Turbocharger (ETC.) can be
made also of aluminum alloys. Currently, cylinder heads are made of aluminum
and magnesium alloys instead of traditional gray cast iron. In the near future,
aluminum alloys will be used to strengthen crankcases [34].
Ceramics made of non-metallic, inorganic materials based on nitrides, carbides
and metal oxides are widely used for weight reduction, friction and wear of highly
11.5 Development Tendencies 167
loaded parts such as propellers. However, the costs of ceramics parts are still high.
Moreover, they cannot fulfill a lot of mechanical and chemical requirements in the
construction yet [35].
168 11 Marine Diesel Engines
DC engine
synchronous engine
rectifier propellor
permanently activated
synchronous engine
asynchronous engine
In last decades, new unconventional materials have been being developed, e.g.,
fine grain carbon and titanium alloys for pistons as a substitute for high-temper-
ature steel alloys. However, the cost of alloys is high on average. Expensive
alloyed parts should be partly replaced by steel with a boron or nitrogen bonus and
spherical cast materials.
Synthetic materials are replacing aluminum in many parts such as in the air
intake lines. The advantages of synthetic materials are their low weight and the
almost unlimited possibilities for form and design. In recent years plastics have
become cost competitive with alloys [36].
For economic reasons, ship construction is decreasing the mass of equipment
on-board. In modern engine design, steel is being replaced by aluminum, mag-
nesium, and synthetic materials. Apart from mass advantages, light weight
materials must show a positive climate balance and high recycling rate.
fuel 100 %
engine radiation
1%
exhaust gas
cooling 18 %
8%
steam for
heating turbo generator
9% 11 %
steam for
other users
1%
shaft output
52 %
Fig. 11.5 Dissipation of energy in a slow speed marine diesel enginediesel engine
pre-mixing fuel
mixing fuel and air intensively pre-evaporating fuel
On average, a slow speed two-stroke marine diesel engine converts more than 50%
of the chemical and thermal energy to mechanical work. With the slow speed of
the piston, the combustion process is more complete than in fast speed four-stroke
engines. Theoretically more than 60% thermal efficiency would be possible, but a
higher heat recuperation rate is not yet possible. The efficiency depends on friction
losses and recuperation of exhaust gases (see Fig. 11.5) [39].
Further improving common rail injection efficiency for large two-stroke engines
is one of the most important technological tasks. In common rail systems, the
pressure in the fuel rail is up to 1,000 9 105 Pa (20.89 9 105 lbf ft-2 or 14,504 psi)
and the valve pressure is up to 200 9 105 Pa (4.18 9 105 lbf ft-2 or 2,901 psi) [40].
170 11 Marine Diesel Engines
160 10.0
[m*s ]
-1
[bar]
150 8.0
145 7.0
140 6.0
2000 2005 2010 2015 2020
year
Most large merchant ships use two-stroke marine diesel engines. Although the
number of them is much lower than the number of four-stroke marine diesel
engines, the two-stroke technology makes up approximately 2/3 of the worldwide
fleet performance. Smaller boats and ferries use spark ignition engines with gas-
oline as fuel and very fast special ships, such as war ships, use gas turbines.
Marine diesel engines apply the best self ignition technology with a high quality
of mixture formation in the combustion chamber. The heat of the burning process
can be used in heat exchangers of the exhaust gas section. In the last decades, the
pressure in the cylinders has increased and has led to higher performance effi-
ciency, lower SFC and decreased exhaust gas emissions.
Fast running four-stroke engines can be easily down-sized and combined with
an exhaust gas after treatment system. In opposite to internal combustion engines,
gas turbines are expensive and are used in high-speed ships, such as ferries. They
were formerly exclusively applied in navy ships.
The progress in marine diesel engine technology over the last ten years can be
summarized as follows:
11.6 Summary and Recommendations: Development of Marine Engine Technology 171
References
1. Schiffsdieselmotor. http://de/wikipedia.org/wiki/Dieselmotor
2. Fuel Saving on Ships up to 15% with the Air Cavity System. http://www.youtube.com/
watch?v=0ry8cpbVHAw
3. Fuel Saving Report for RCL Ship Management (PTE) Ltd. http://www.tkfuels.com.au/
SiteMedia/w3svc967/Uploads/Documents/
Fuel%20Saving%20Report%20to%20RCL%2056475_small.pdf
4. Brake specific fuel consumption. http://www.autospeed.com/cms/title_Brake-Specific-Fuel-
Consumption/A_110216/article.html
5. What is BMPE? http://www.bmepfuelandtuning.com/html/what_is_bmep_.html
6. NOx monitors for ships. http://www.nauticexpo.com/boat-manufacturer/nox-monitor-ships-
20974.html
7. Guider T Ph (2008) Characterization of Engine Performance with Biodiesel Fuels. Lehigh
University. http://www.cmu.edu/iwess/publications/biodiesel/guider_ms_thesis.pdf
8. The marine diesel engine diesel. http://www.nauticexpo.com/boat-manufacturer/nox-
monitor-ships-20974.html
9. Pounder’s marine diesel engines and gas turbines. http://www.books.google.com/books?id=
RC_k4q6y-JIC&pg=PA143&hl=de&source=gbs_toc_r&cad=4#v=onepage&q&f=false
10. Wärtsila RT-flex96C. http://www.wartsila.com/en/engines/low-speed-engines/RT-flex96C
11. Woodward controls for marine and naval applications. http://www.woodward.com/
Applications-MarineandNaval.aspx
12. Learn about marine fuel types & additives. http://www.marinefuel.com/about-marine-fuels/
13. Sankey diagrams. http://www.sankey-diagrams.com/ship-engine-efficiency-visualized/
172 11 Marine Diesel Engines
14. Marine diesel engines & marine gas turbines information center. http://www.virtualpet.com/
pe/portals/mdrive.htm
15. MAN schnelllaufende Schiffsdieselmotoren im leichten, mittelschweren und schweren
Betrieb. http://www.mandieselturbo.de/files/news/filesof10371/Leporello_Schiffsdieselmo
toren_03-12.pdf
16. Jet engines for marine propulsion. http://www.brighthub.com/engineering/marine/articles/
61952.aspx
17. Marine diesel engine improvements on the efficiency. https://www.maritimejournal.murdoch.
edu.au/index.php/maritimejournal/article/viewFile/126/172
18. Scavenging and supercharging. http://www.tpub.com/engine3/en32-1.htm
19. Influence of ambient temperature conditions on main engine operation of MAN B&W two-
stroke engines. http://www.mandiesel.com/files/news/filesof762/5510-0005.pdf
20. Charge air cooler. http://en.wikipedia.org/wiki/Charge_air _cooler
21. Engines data. http://www.crmmotori.it/v12_enginesdata.htm
22. The Marine fuel-consumption operator. http://www.monohakobi.com/en/solutions/environ
mental/fuelnavi.html
23. Engine cooling systems explained. http://www.boatsafe.com/nauticalknowhow/cooling.htm
24. Marine diesel engine cylinder pressure analyzer. http://www.techno.mes.co.jp/english/
products/de/MES-EPOCH_e.pdf
25. Diesel & Bio-fuel exhaust gas temperature EGT sensor with compression fitting. http://
www.thesensorconnection.com/egt-probe-thermocouples/sensors/exhaust-gas-temperature/
egt_diesel_probe.shtml
26. Exhaust gas emissions from ship engines. Significance, regulations, control technologies.
http://www.maritimejournal.murdoch.edu.au/index.php/maritimejournal/article/viewFile/
126/172
27. Compressor stall. http://en.wikipedia.org/wiki/Compressor_stall
28. Fuel injection system technology. http://www.fev.com/content/public/default.aspx?id=478
29. Exhaust gas recirculation. http://en.wikipedia.org/wiki/Exhaust_gas_recirculation
30. Poppet valve. http://en.wikipedia.org/wiki/ http://en.wikipedia.org/wiki/Poppet_valve
31. Piston ring manual. http://www.federalmogul.com/korihandbook/en/index.htm
32. Turbocharger compressor calculation. http://www.federalmogul.com/korihandbook/en/index.
htm
33. Precipitation hardening ferritic-pearlitic steel valve. http://www.freepatentsonline.com/
5286311.html
34. Aluminium compressor wheels casting for turbochargers. http://www.turbotech.co.uk/
35. NR-Ceramic pistons. http://www.image.dieselpowermag.com/f/diesel-engines/nr-ceramic-
pistons/34289610/nr.jpg
36. Engine air intake. http://www.roechling.com/en/automotive-plastics/products/engine-air-
intake.html
37. What are the main types of ship propulsion systems? http://www.brighthub.com/engineering/
marine/articles/27452.aspx
38. Diesel_electric transmission. http://www.en.wikipedia.org/wiki/Diesel_electric_transmission
39. Clausen NB, Marine diesel engines: How efficient can a two-stroke engine be? http://www.
ship-efficiency.org/onTEAM/pdf/Clausen.pdf
40. Sulzer RT, Flex marine diesel engine. http://www.dieselduck.ca/machine/01%20prime%20
movers/rt_flex/index.htm
41. Sulzer RTA84C and RTA96C engines. http://www.dieselduck.ca/machine/01%20prime%20
movers/Sulzer%20SRTA84C-96C.pdf
42. Demmerle R (1997) The reliable driving forces for large, fast containerships technologies.
Review. Sulzer RTA-C. http://www.dieselduck.ca/machine/01%20prime%20movers/
Sulzer%20SRTA84C-96C.pdf
Chapter 12
Type Approval and Type Certification
Legislation prescribes strict procedures for the approval and the certification of
vehicles, airplanes, and ships worldwide, but the requirements are different in
individual countries.
Vehicles are checked during the production phase in the ‘‘Compliance of produc-
tion’’ which tests the gas and particle emissions of new motor vehicles. This
examination decides whether production may be continued or not. The statistical
rule for the sampling is very different in Europe, in the USA and in California [1].
Random Field Monitoring (FM) of used motor vehicles must prove whether the
exhaust gas limits are maintained after approximately 80,000 km (49,720 mi) and
160,000 km (99,441 mi). This examination decides whether the producers will get
a certificate verifying the fulfillment of the regulations over the defined runtime.
Otherwise the manufacturer must recall all motor vehicles of that series to get
them modified.
Figure 12.1 summarizes the main methods of quality control of vehicles.
Type Approval (TA) is prescribed for manufacturers to qualify the first type of
vehicles. This examination decides whether a new type of vehicle or an existing
vehicle with substantially changed parts, may be produced.
In the future, Self Diagnosis can complete the methods of quality control. It can
contribute to the improvement of mobile Field Monitoring.
Self Diagnosis
of Control Units
Type Approval On-Board Diagnosis and
and On-Board Measurement
Type Certification
Control of
Durability In Use Compliance
Compliance of Production
There are many different regulations regarding exhaust gas legislation (see
Fig. 12.2) [2].
Nowadays, the decreased emission limits increasingly determine the general
equipment of vehicles, the fuel consumption of the engines, and the quality and the
quantity of the exhaust gas after treatment systems. The worldwide limitation of
exhaust gas emissions has resulted in an average decrease in the output of
pollutants in the last decades. In new fleets, unburned hydrocarbons have been
decreased by up to 97–98%, CO, NO, and NO2 have been reduced by up to
95–96%, and particles have been lowered by up to 90–91%.
The legislation concerning the examination of exhaust gas quality is very
similar in all countries. Classification procedures are divided into processes for
passenger cars, light, medium, and heavy-duty vehicles.
The examination is a highly complex and detailed procedure, which can only be
done in specific certified institutions.
In the Type approval procedure, the motor vehicle is put on a roller test stand
which simulates the traction resistance on the road. The driver sees the driving
cycle with accelerating, delaying, braking and stopping. Exhaust gas samples are
collected in Teflon bags. Constant Volume Sampling (CVS) technology is used to
achieve a constant flow rate of the diluted exhaust gas and to avoid condensation
of water vapor in the sample [3].
12.1 Tests of Vehicles 175
Tier 0 Tier 1
FTP EPA NLEV Tier 2
US 87 US 94
US test
cycle
CARB TIER 0 TIER 1 LEV 1 TLEV1 LEV1 ULEV1 ZEV1
2)
LEV 2 LEV2 ULEV2 SULEV2 ZEV 2 LEV 3
Fig. 12.2 Test procedure in guidelines for the measurement of emissions for passenger cars
During the determination of pollutants, the exhaust gas is diluted with air.
Volume flow is calculated from the air and the exhaust gas by a dilution ratio of
approximately 1:8. A part of the exhaust gas is collected in three bags, from the
three sections of the US driving cycle. The European test procedure combines the
three samples into one bag. In addition, a part of the ambient or outside air is filled
into three bags or into one bag to provide a comparison to the basic pollution level.
The concentrations of the exhaust gas sample and of the ambient air compo-
nents are measured with certified analyzers. The concentrations in the ambient air
must be subtracted from the exhaust gas sample. The multiplication of the con-
centration with the flow rate and the integration over the whole driving route yields
the weight of emissions per distance in g km-1 or g mi-1 for passenger cars and
emissions per performed work in g (kW h)-1 or g (bhp h)-1 for heavy commercial
vehicles.
In the EU, cars and light duty vehicles are examined at roller test benches. The
emissions of complete HDVs are estimated only for experiments at a specific roller
test bench if it is required during the development. The engines of heavy-duty
vehicles are usually examined at the engine dynamometer test bench. In both
cases, at the roller and the dynamometer engine test bench, the driving cycle is
regulated and steered by a computer program. The operation can be processed by
test drivers who drive the car in accordance with the commands on the computer
display. These displays give the speed and the gear including braking and accel-
erating. The other way is the use of automats which move pedals and levers in the
car with bowden cables or steering bars.
In the USA, the Federal Test Procedure (FTP) 75 is similar to the NEDC in Europe
[4]. However, in contrast to the European procedure, in the US FTP 75 test
separate driving cycles are prescribed for the high-speed portion (UDDS), for
aggressive driving characteristics (US06) [5], for driving with operating auxiliary
176 12 Type Approval and Type Certification
devices, e.g., lights and air conditioning system (SC03) [6] and for the Highway
Driving Cycle (HDC) (see Fig. 12.3) [7].
The Start Control Cycle SC 03 is driven after the appropriate preconditioning
and subsequent 10 min holding time with the air conditioning switched on at an
ambient temperature of 35C (95F).
In the US 06 cycle, emissions are measured at high average speeds. It is used as a
‘‘hot-start test’’ at the normal test temperature of 20–30C (68–86F). The full test
consists of preconditioning the engine to a hot stabilized condition, as specified in
§86.132-00.
In the USA, the balance between several methods is permitted. The substitution
of different methods is possible if they contribute to the improvement of air quality
and emissions do not exceed the limits.
12.1 Tests of Vehicles 177
Fig. 12.4 Japanese Driving Cycle JC 08 for passenger cars Luca Gray (08/12/11)
Emissions of heavy-duty vehicles are tested in the USA at a roller test bench
with specific dynamometer transient driving cycles for HDVs. The methods in the
USA are similar to the European Cycles in principle, but have a different specific
speed profile and specify different gears [8].
In Japan, there are old driving cycles such as the Japanese 11 and Japanese
10 ? 15 modes [9], and new cycles such as the Japanese Cycle JC 08 for pas-
senger cars and Japanese Cycle JE 05 for heavy commercial vehicles [10, 11].
The length of 11 mode cold cycle is 4.084 km and the time is 480 s. It involves
a maximum speed of 60 km h-1, i.e., 37.3 mph and an average speed of
30.6 km h-1, i.e., 18.6 mph.
The 10 ? 15 mode is a hot cycle. The driving time is 892 s; the distance is
6.34 km, i.e., 3.94 mi, the average speed is 25.61 km h-1, i.e., 15.9 mph; and the
maximum speed is 70 km h-1, i.e., 43.5 mph. Emissions are measured in the last
four segments over 4.16 km, i.e., 2.6 mi in the time interval of 600 s.
The Driving Cycle JC 08 is measured over a distance of 8.2 km, i.e., 5.1 mi,
and a time of 1,205 s at an average speed of 24.4 km h-1, i.e., 15.2 mph with a
maximum speed of 80 km h-1, i.e., 49.7 mph (see Fig. 12.4).
The control cycles are different in the EU, the USA, and Japan, similarly to the
passenger car control methods. However, there are harmonized test cycles which
are based on world-wide pattern of real heavy commercial vehicle use. Two
representative cycles, a transient test cycle (WHTC) with both cold and hot start
requirements and a hot start steady-state test cycle (WHSC) belong to the cycle.
The test time of WHTC is 1,800 s with several monitoring segments [12].
178 12 Type Approval and Type Certification
2)
Holder Producer
The International Operation Safety Audit (IOSA) of the IATA for the airlines and
the ICAO for the government belong to the international organizations [13].
Membership obligates each member state to apply and to keep the ICAO standards
and recommendations in their national legislation concerning aviation. In most
countries, the Ministry for Transportation is the highest national authority in
aviation [14].
Figure 12.5 shows the structure of international and national organizations.
The criteria for airplane certification are:
• The prototype must be approved;
• The airworthiness must be checked;
• The owner must be insured;
• The airplane must be registered in the list of the official national aircraft; and
• The maximum permissible noise, gas and particle emissions must be lower than
the limit [15].
IATA vision 2050 represents a positive trend for the air transport industry by 32
million jobs, €2.45 trillion, i.e., US $3.5 trillion in economic activity and a growth
up to 16 billion of passengers and 400 million tons of freight yearly [16].
The main procedure is the Type Sample Test examination prescribed in the air-
worthiness requirements [17]. The aviation authority is responsible for carrying it
out, but the test can be delegated to development companies. It is usually done for
the military by the office for military technology and procurement [18].
12.2 Tests of Airplanes 179
The regulations called Joint Aviation Requirements (JAR) are published by the
Joint Aviation Authorities (JAA) on behalf of the member states [19]. The JAA
was founded by the European Civil Aviation Conference (ECAC) which is the
European organization of the ICAO. The members are the ministers for trans-
portation of the European countries and representatives from the European
Aviation Safety Agency (EASA) which is the airworthiness authority for aviation
in the EU [20].
The JAA have adopted a set of harmonized rules for commercial air trans-
portation, called Joint Aviation Requirements for Commercial Air Transportation
(Airplanes) (JAR-OPS 1). These regulations provide for common safety standards
of the designers, the manufacturers, the operation and the maintenance of the
aircraft, as well as aviation personnel and organizations. In detail, the regulations
contain requirements for the flying characteristics, the construction, the engine
installation, the type and the operation limits of equipment. The civilian con-
struction specifications have to refer to a series of requirements according to the
JAA [21].
The JAA is an organization operated by volunteer European Civil Aviation
Authority (CAA). EASA has taken over most of the JAA regulations, thereby
creating the EASA requirements which are presented in Table 12.1. [22].
180 12 Type Approval and Type Certification
exhaust
nozzle
nozzle center line sampling
sample
transfer
line
minimum of 4
mozzle diameters
nozzle sampling
exit point
span zero
exhaust pump
zero span
pump
zero span
NOX
analysis
Fig. 12.7 Exhaust gas analysis system for Type certification of aircraft engines
The Joint Aviation Requirements for Auxiliary Power Units (JAR-APU) are based
on the FAA’s Technical Standard Order TSO-C77a [27]. Subpart A provides the
airworthiness requirements for the issue of Joint Technical Standard Order (JTSO)
authorizations for turbine powered APUs used on an aircraft [28].
The relevant EASA, Subpart B design and construction regulations for all types
are contained in Table 12.3 [29].
APU 250 and 260 deal with fuel consumption and emissions. In accordance
with these requirements the exhaust gas systems must be designed and constructed
to prevent leakage of exhaust gases into the aircraft. The exhaust piping has to be
constructed of fireproof and corrosion resistant materials.
The relevant EASA regulations of Subpart C for all APU type substantiations
are shown in Table 12.4.
Subpart D contains the additional requirements (see Table 12.5).
12.2 Tests of Airplanes 183
Classification and judgment, the organization of ships into classes, the regular
supervision of their maintenance, the standards for design, construction or con-
struction specifications, and marine technology research are done by the Interna-
tional Association of Classification Societies (IACS) [34]. The oldest classification
society, Lloyd’s Register Group for shipping, was founded in London in 1760 with
184 12 Type Approval and Type Certification
the main goal of enhancing the safety of life and property for the benefit of the
public and ultimately, the environment [35].
Nowadays, there are ten internationally recognized classification societies
which are organized under an umbrella organization in the IACS. There are further
approximately 30 other classification societies which do not correspond to the
international quality standards of the IACS.
Statutory inspections manage security on-board, supervise safety regulations for
labor conditions, and for environmental protection that are made by flag states.
Class-conforming ships receive corresponding certificates from the classification
society [36]. They contribute to maritime safety and regulation through technical
support, compliance verification, and research and development. More than 90%
of the world’s cargo carrying tonnage is covered by the classification design,
construction compliance and life-cycle assessment. Rules and standards set by the
member societies of IACS.
Regulations for the Prevention of Air Pollution from ships were adopted in the
1997 Protocol to MARPOL 73/78 and are included in Annex VI of the Convention
[37]. They came into force in 2005 after ratification by 15 member states of the
IMO, which represent more than 50% of the world tonnage. Regulations 13 and 14
of the Annex VI set limits for NOx from diesel engines and for SOx emissions from
ships [38].
Similar to aviation technology, the rules of the IMO are valid internationally in
contrast to road transportation whose rules are only valid within national or
regional frames. The IMO regulations are moderately competition-neutral.
Monitoring takes place via national classification societies, professional envi-
ronmental associations and government port controls. Classification societies have
also created new classes like the Environmental Passport [39], the awards for
Environmental Protection [40], Clean Ships and Clean Design in recent years [41].
In 2010, the Marine Environment Protection Committee (MEPC) [42] of
MARPOL introduced two drafts, the Energy Efficiency Design Index (EEDI) [43]
and the Ship Efficiency Management Plan (SEMP) [44] for decreasing Green
House Gas (GHG) emissions for the UN Framework Convention on Climate
Change (UNFCCC) [45].
A special problem arises from the sulphur content of heavy marine fuels on ships
(see Table 12.6) [46].
12.3 Tests of Ships 185
The MARPOL 73/78 Convention, Annex VI, Regulation 13 sets the limits for
nitrogen oxide emissions of international seagoing vessels [49].
Strengthened emission standards for new ships were adopted by the IMO in
2008, NO x emissions from international shipping in European sea areas are
186 12 Type Approval and Type Certification
20.0
5.0
Tier III ( NO X Emission Control Areas )
0.0
0 200 400 600 800 1000
-1
number of revolutions [min ]
projected to increase by nearly 40% between 2000 and 2020. The reason is that by
2020, the emissions from shipping around Europe are expected to equal or even
surpass the total from all land-based sources in the 27 EU member states com-
bined. In addition to the NO x requirements for new ships from 2011, the IMO
decided that in ECAs, ships built after 01 January 2016 will have to reduce
emissions of NO x by about 80% from the current limit values.
Figure 12.8 shows the course of NOx limits depending on the number of rev-
olutions [50].
Besides international legislation, national regulations also limit exhaust gas
emissions, e.g., in Sweden, in Norway and in the USA. The authority in Alaska limits
the visible emissions of seagoing vessels by the Alaska Marine Vessel Visible
Emission Standard (18 AAC 50.070). The exhaust opacity at the end of the exhaust
pipes is limited to 20%. Short excesses are allowed during maneuvering [51].
Europe Directive 97/68/EC, amended by 2004/26/EC, sets limits on the emis-
sions of diesel engines on inland navigation vessels [52, 53]. The limits correspond
to step two (Tier II) of the US EPA ship guidelines [54].
There is a large variety of laws and regulations concerned with reducing fuel
consumption and emissions. Despite this variability, the procedures for quality
control, production and operation are very similar for vehicles, airplanes and ships.
Type Approval is the most important procedure for the permission of mass pro-
duction of vehicles.
12.4 Summary and Recommendations: International Type Approval 187
The ship certification depends on the regulations, ratified by the IMO. Basic safety
requirements are specified in the EU in EEC and EC guidelines, which are to be
partially taken over by national governments. Leading the proceedings in Europe
188 12 Type Approval and Type Certification
are the environmental requirements for the Rhine, contained in the Central
Commission for Navigation on the Rhine (CCNR). Further important guidelines
for ship certification are:
• 96/98/EC concerning marine equipment amended by 2002/75/EC [55][56];
• 98/18/EC concerning safety regulations and standards for passenger ships
amended by 2002/25/EC and 2003/24/EC [57][58][59];
• 1999/5/EC concerning radio installation and telecommunication terminal
equipment according to international requirements of the Committee Interna-
tional Special des Perturbations Radioelectriques or International Special
Committee on Radio Interference (ISPR) [60];
• 2004/108/EC concerning electromagnetic compatibility [61]; and
• 2006/87/EC concerning technical requirements for vessels on inland waterways
amended by 2008/87/EC, 2008/126/EC and 2009/46/EC [62][63][64][65].
References
Standards
Definition of
Site definition Scope definition Material definition
structure
Catalogue for
Guide for repair
replacement parts
Supervision
by the public sector (national, state, or local governments). Estimated that inspec-
tion and maintenance costs are from 2 to 15% of the world’s total transportation
costs [5].
Inspection has very similar procedures in all regions of the world. Small differ-
ences in practice result from the different infrastructure of control organizations
and vehicle manufacturers.
Computer supported diagnostic methods are increasingly used in the inspection
and examination procedures. Current diagnostic systems contain electronic
13.1 Inspection and Maintenance in Road Transportation 193
failure-code
16-pol OBD interface RS 232
exhaustion
equipment and an external test device, which can be adapted to the motor vehicle
via an OBD interface (see Fig. 13.2) [6].
After the connection with the interface, the test equipment automatically adjusts
itself to the data transfer system used by the engine control device. The stan-
dardized format is specified for the nomenclature of components and systems
which are obligatory for all manufacturers.
Electronic systems and computer technology open novel possibilities for electronic
detection of errors in motor vehicles. Monitoring was first introduced in spark
ignition engine technology. Nowadays, OBD controls the function of all exhaust
gas components with a comprehensive monitoring system (see Table 13.2) [7].
Because of the multiplicity of information, the signals of individual elements
are transferred via a CAN bus to the motor management system.
194 13 Inspection and Maintenance
Figure. 13.3 shows the complexity of the OBD in a spark ignition direct
injection engine, model DI Motronic which has an Electronic Accelerator Gas
pedal (EGAS), an Engine Control Unit (ECU) and an electronically controlled
exhaust gas recirculation system [8].
13.1 Inspection and Maintenance in Road Transportation 195
Misfires causing an engine to run roughly are the most serious indication of
ignition problems. There are two different classes of misfires
• Irregular operations that endanger the engine; and
• Exhaust gas misfires that endanger the catalyst.
OBD technology permanently records the rough running of the engine from the
angle speed of the crankshaft. If the rough running exceeds the limit, the number
of misfires is counted [9].
The monitored systems are checked at specified intervals once per driving
cycle, if the main operating conditions are within the defined range. The conditions
are the operation temperature of the catalyst, the temperature of the coolant, the
number of revolutions, the engine load and the status of the secondary air system.
If the conditions are not in the defined range, the diagnostic function is not
processed [10].
Besides thermal or mechanical deterioration of the catalyst, the normal aging
process lowers its normal conversion rate. The exhaust gas after treatment system
contains the mixture controlling and monitoring k sensors. The catalyst’s oxygen
storage capability is measured to determine its operability. The storage capacity is
represented by the comparison of the mixture controlling k signal (upstream of the
catalyst) with the monitoring k signal (downstream of the catalyst) [11].
The tank ventilation system is controlled by the electric function of the tank
ventilation valve. In Europe, tank leak diagnosis is not required in contrast to the
OBD II in the USA. The manufacturer must merely ensure the tightness of the
filler cap. This can be done with the help of an electronic control system or a
security tape [12].
The monitoring of self ignition engines originates from the technology in spark
ignition engines. In Europe, the legal system of rules (98/69/EC) comprehensively
prescribes the requirements of the OBD technology in vehicles with a self ignition
engine (see Table 13.3) [13].
The OBD in a self ignition engine with Common Rail technology is shown in
the Fig. 13.4 [14].
196 13 Inspection and Maintenance
air
3 1
fuel
2
4
7 5
6
air
18
air recirculation 25
8
19 26
14
9
20 21 23 24 29
10
exhaust
11 engine 17 22 27 28
reinforced lines
12
13 30 15
31 32 exhaust
16
The OBD system must monitor the exhaust gas components, the subsystems
and the electric components, whose malfunction could lead to exceeding the
defined limits. The standardized MIL signals the errors.
Faulty injection as well as loss of compression as a result of mechanical dis-
turbances in the engine leads to incomplete combustion with increased emissions.
13.1 Inspection and Maintenance in Road Transportation 197
MRB report
Requirements and aims are described within the Maintenance Program (MP) and
methods are summarized in the Aircraft Maintenance Manual and in the Task
Cards [25]. The work of the maintenance is recorded by the Maintenance Review
Board (see Fig. 13.6) [26, 27].
The extent of the maintenance event depends on the number of flight hours, the
number of landing cycles, and the time elapsed. Each event in the life of an
airplane, e.g., flight, maintenance, and repairs that are evaluated and recorded have
an influence on the MP [28].
Maintenance events include the routine examination of technical systems which
are important for the daily operation as well as a thorough overhaul of the airframe.
Depending on the aircraft type, the A Check must be done every 350–650 flying
hours and the B Check approximately every 3 months. The C Check means the
detailed inspection of the airplane structure and the test of the system. Depending
upon the type of aircraft, the C Check is done every 12 months (see Table 13.5)
[29].
Measurement of combustion processes does not belong to the typical control of
engine technology yet, although changes due to wear caused by engine operation
lead to higher fuel consumption and higher exhaust gas emissions.
The Maintenance Steering Group (MSG) has its own type of maintenance
philosophy and requires a change within the organization of air carriers [30].
A MSG-3 supports the operational safety net and provides a positive contri-
bution to the fiscal bottom line of air carriers. It was released by the Air Transport
200 13 Inspection and Maintenance
, , , , , , ,
Before any departure, there is a visual check of the airplane’s outer surface and
parts for damage, leaks, missing parts and an inside check that the aircraft systems
are functioning properly. Furthermore, crew have to study the documents on
previous maintenance activities and maintenance related crew reports filed in the
operator’s on-board technical flight log, i.e., the Airplane Flight Log (AFL) and the
Deferred Item Record (DIR) [35].
The decision to ‘‘go’’/‘‘not go’’ is aided by the manuals Minimum Equipment
List (MEL) and Configuration Deviation List (CDL) concerning those missing or
inoperable minor items and related actions to be followed which can be tolerated
for a short period of time without compromising safety [36, 37].
In inland shipping, specialists can be brought in. At sea, the crew does the
inspection and operates the diesel engines, pumps, compressors, steam generating
units, cooling systems, fresh water plants, fire-extinguishing systems, electric and
computer plants, etc. The crew has an increased responsibility because of the
increasingly complex technology on board [48].
Fuel accounts for 20–40%, in specific cases for 40–60% of an average shipping
company’s total operating costs [49]. Therefore, fluctuations in oil prices directly
influence earnings. Fuel and exhaust gas emission saving measures adapted for
energy conservation and profitability are the most important tasks. In the future,
exhaust gas emissions devices can be effectively controlled not only with on-board
measurement technology but also by using remote sensing methods.
The working efficiency of mechanical and electrical equipment has a direct
impact on the fuel consumption, on the maintenance, and on the efficiency.
Nowadays, crew members must not only navigate ships, but must be able to adjust
the angle of fuel injection to the right position to reduce the lag time for ignition
and improve heat efficiency. Cleaning the air inlets and exhaust gas outlets can
also decrease fuel consumption and exhaust gas emissions by 2–3% [50].
Periodic checks of cylinders improve the timing of the valves and the injection
pressure, the mechanism of the fuel pump, the plunger coupling, the fuel injector
spring, and the needle valve coupling. Failures in the central elements of the
204 13 Inspection and Maintenance
engine can cause a serious increase in fuel consumption and exhaust gas emis-
sions. Preventions hinder wear of components in the combustion chamber, e.g., air
leak which usually leads to damage to cylinders, pistons, and piston rings [51].
The maintenance of the lubrication system reduces mechanical friction and
wear. It is important to raise the cooling water temperature of diesel engines to
65–90C (149–194F). Fuel is not optimally used at low temperatures, because
higher fuel viscosity increases the friction and resulting wear of parts. Preventing
oil leaks, especially at the connection of the oil injection and return line, improves
fuel efficiency [52].
Optimal use of waste heat helps to decrease fuel consumption [53]. About 40%
of all the heat generated is turned into the output power, while the rest is lost
outside of the ship through heated fuel tanks and pipes, exhaust gases, and cooling
water [54, 55].
Fuel consumption is also decreased through careful maintenance of the turbo-
charger, by periodic cleaning of the air filters and removing soot from the exhaust
gas [56].
Besides technology, the economical plan of the routes and the shipping sche-
dule are decisive for fuel consumption as well as for exhaust gas emissions. The
choice of the most efficient port for avoiding congestion and having optimal
connections to road and rail transportation are also decisive. Routes should be
optimized according to the sea conditions and to the weather which strongly
shortens or extends the journey distance and time. Efficient navigation helps to
avoid unnecessary detours and dangerous situations. Rational use of ocean currents
and winds also reduces fuel consumption.
Modern telecommunication and Internet provide topical information about
traffic. This makes it possible to avoid creating bottlenecks at water ways and in
harbors, and enabling rational storage of goods. Freight transportation usually
needs cargo for the return trip. Shipping companies cooperate in purchasing fuel.
Energy conservation management and the proper handling of waste oil usually
conserve 1–3% of fuel [57].
Ships in harbors are more and more switching to shore power and replacing
their shipboard generators to save fuel and exhaust gas emissions near environ-
mentally sensitive areas [58].
OBD is the indirect monitoring of the combustion and the emission systems.
The first systems were developed in the 1980s for the continuous inspection of
vehicles. Today, a malfunction can be precisely recognized by logical evaluation
of individual sensor values and by comparison of the measured values with stored
reference data of the operating point.
In exactly defined check routines, the OBD system starts periodic tests for
monitoring the quality of controlled elements with sensor signals. Since the
introduction of OBD, manufacturers are obliged to uniformly define and store
malfunctions and to transmit MIL signals to the interface of the system.
Preventive maintenance and repairs are vitally important for vehicles to ensure
that they operate reliably. In well maintained vehicles, repairs are done only if a
component fails by external influences.
Beside the maintenance and repair manual, there is also a list of replacement
parts. It specifies which modules must be replaced after certain time periods of
engine operation.
The results are definitions of required maintenance which are usually described
in the job cards. Electronic or paper card systems usually contain the number and
the qualification of the workers, the lists of the necessary tools, the set-up times,
and the safety requirements for the ship.
The engine document lists only original parts for replacements. Using unau-
thorized parts for maintenance or for repair invalidates the guarantee and the
confirmation of the Type approval.
References
1. Intelligent transportation system inspection and maintenance manual. (ITSIMM) 02. 19.
2008. Rutgers, the State University of New Jersey. http://www.rits.rutgers.edu/files/training_
presentation.ppt
2. Frangopol DM, Lin KY, Estes AC, Life-cycle cost design of deteriorating structures. http://
www.digitalcommons.calpoly.edu/cgi/viewcontent.cgi?article=1013&context=aen_fac
3. A briefing book for transportation decision makers, officials, and staff. A publication of the
transportation planning capacity building program. Federal highway administration. http://
www.planning.dot.gov/documents/briefingbook/bbook.htm
4. Corrosion costs and preventive strategies in the United States. http://www.corrosioncost.com/
pdf/techbreif.pdf
5. Calculating national logistics cost. http://www.unescap.org/ttdw/Publications/TFS_pubs/
pub_2194/pub_2194_Appendix.pdf
6. Commission Directive 2001/9/EC of 12 February 2001 adapting to technical progress
Council Directive 96/96/EC on the approximation of the laws of the Member States relating
to roadworthiness tests for motor vehicles and their trailers. http://www.eur-lex.europa.eu/
LexUriServ/LexUriServ.do?uri=OJ:L:2001:048:0018:0019:EN:PDF
7. Impact assessment/On Board Diagnostic (OBD) systems for passenger cars. http://www.ec.
europa.eu/enterprise/sectors/automotive/files/projects/report_obd_en.pdf
8. Abgasuntersuchung. Handbuch zur AU-Schulung von verantwortlichen Personen und
Fachkräften. Schulungsphase 2008–2011. TAK. 2008 Bonn. info@tak.de
9. Auto systems and repair. http://www.repairpal.com/OBD-II-Code-P0300
10. On board diagnostic (OBD) function. http://www.europeantransmissions.com/Bulletin/
DTC.audi/01V%20DTC%20read%20out.pdf
11. Overview of OBD and Regulations. Toyota motor sales USA. http://www.autoshop101.com/
forms/h46.pdf
12. Evaporation emission system components. http://www.aa1car.com/library/evap_system.htm
13. Diesel OBD/AU. http://www.aa.bosch.de/aa/de/berufsschulinfo/media/2006_4.pdf
14. Summary for 6.7L diesel engines. http://www.motorcraftservice.com/vdirs/diagnostics/pdf/
DOBDSM1101.pdf
15. Summary for 7.3L diesel engine. http://www.motorcraftservice.com/vdirs/diagnostics/pdf/
DOBDSM971.pdf
16. Diesel injection common faults and maintenance points. http://www.obdchina.com/diesel-
injector-common-faults-and-maintenance-points-5177.html
17. Garrett by Honeywell. Turbo application search engine. http://www.turbobygarrett.com/
turbobygarrett/tech_center/turbo_optimization.html
References 207
The word ‘‘navigation’’ historically means the art of the steering a ship. Therefore,
changes in operation are related to the route and the journey. Today, navigation is
a widely used method for the optimal regulation of traffic on roads, water, and in
the air. There are two preconditions for modern navigation [1]:
• Precise determination of the vehicles’, airplanes’, and ships’ position; and
• Knowledge of the best routes to the planned destination under current
conditions.
Navigation consists of different elements in road traffic, in aviation, and in
shipping, but the basics are similar in all types of transportation.
optical
receiver
Navigation systems help to find the fastest way to a certain destination. New
systems calculate not only all possible ways but also the routes with the shortest
direction and the smallest fuel consumption across the field [7].
Route calculation improves services and profits and protects the environment.
Trucking firms usually use a special algorithm for the calculation of the most
economically optimal and least polluting route. This technology offers enormous
profit potential for trucking services. High capacity computers determine the
optimal route within milliseconds. Saving fuel means decreasing CO2 and pollu-
tant emissions and also a decrease in other pollutants. Self Diagnosis system can
support ecologic navigation in a network due to communication between the
vehicle and an electronic checkpoint.
Congestion in traffic including different accelerating and braking phases of a lot
of vehicles leads to higher concentrations of exhaust gases in the local environ-
ment. Fuel consumption and exhaust gas emissions can be particularly effectively
decreased if traffic light signals are synchronized. Other measures of traffic
organization, e.g., the construction of modern roads, the removal of redundant
crossings, etc., also contribute to lowering the specific fuel consumption and the
specific exhaust gas emissions per road vehicle. However, optimally organized
traffic conditions often lead to an increasing amount of traffic which usually causes
more global fuel consumption and higher global pollution on reconstructed and
renewed roads.
Navigation supports not only the best route but also the choice of the optimal
speed. Increasing the velocity of commercial vehicles weighing 25–40 t on roads
in villages, cities, and highways leads to higher fuel consumption; see Fig. 14.3
[8].
Not only accelerating but also braking requires surplus fuel. Braking from 90 to
60 km h-1 (55.9–37.3 mi h-1) on a highway leads to additional fuel consumption
of approximately 0.7 l (0.18 gal (US) and 0.15 gal (UK)) of diesel fuel. The time
advantage of not driving with foresight is small, because basic traffic conditions
strictly determine the time needed to the destination, independently from short
accelerating and decelerating phases; see Fig. 14.4.
Higher than optimal speed leads not only to increased fuel consumption and
exhaust gas emissions but also to more accidents. Fuel and emissions can be saved
and unnecessary stops and goes can be avoided with foresight to recognize
obstacles in time by observation and navigation [9].
212 14 Navigation
41.0
26 t
40 t
36.0
fuel consumption
[1*(100*km)-1]
31.0
26.0
21.0
16.0
73 75 77 79 81 83
velocity [km*h-1]
Fig. 14.3 Fuel consumption of mixed driving on country roads and highways depending on
speed and load
50
foresighted driving
aggressive driving
40
velocity [km*h-1]
30
20
10
0
0 50 100 150 200 250
time [sec]
driving direction
in case of turning off automatic control of sensors and actuators automatically maintain distance
traffic order
adjustment
regulation
planned
result
communication
achieved
result
actuator sensor
Complex driving assistant and monitoring systems must control distance, speed,
and direction in front of and behind the convoy and between the vehicles in the
convoy; see Fig. 14.6.
Automatic driving assistant systems are still in the predeveloping phase.
Current route planning systems already effectively save fuel. Drivers using traffic-
enabled navigation devices are spending 18% less time driving on an average trip
versus drivers without navigation [12].
Airport layout, the infrastructure, and the organized ground movement determine
the distance and the time that an airplane has to travel between its parking position
and the runway. This movement may unnecessarily increase fuel consumption on
214 14 Navigation
the ground. The length and the altitude restrictions for landing and the required
turns for departure and arrival routes also influence fuel consumption. Planners who
design departure and arrival routes have to consider alleviating noise over popu-
lated areas and the terrain and the airspace requirements of nearby airports [13].
The airline must also decide the construction of aircraft, the types of on-board
equipment, the kind of license, and the rating of the pilots. On-board navigation
equipment must match with the radio waves to the ground equipment along the
flight path [14].
Each nation maintains its own Air Traffic Service (ATS) services responsible for
flights within its territory. The ATS system consists of flight information, alerts, air
traffic advisory, and air traffic control (ATC) services.
No aircraft is allowed to enter into or operate within a controlled airspace unless
it has ATC clearance, except for a few but strictly regulated cases. A flight is
controlled when it is subject to ATC clearance. Over the high seas, the ATC
services are provided according to regional agreements concluded by the nations
involved.
There are generally three basic controls and some subdivision services in air
traffic; see Table 14.2 [26].
ATC Services can be divided or integrated otherwise and further subdivisions
can be established according to the traffic volume and to the density of structural
elements, such as the airports and the airways. The terminal control of the airport
14.2 Navigation in Aviation 215
and possible subdivisions is responsible for the control of confluenced routes in the
vicinity of the airport which covers an area, typically 50–80 km (27.0–43.2 nmi)
around the airport [28].
In addition to its basic functions, ATC may provide weather advisories, terrain
information, navigation assistance, and other services to pilots. ATC is vital for
maintaining separation between aircraft flying at high speed in congested areas and
bad weather when pilots are unable to see the environment and for avoiding
distances to other aircraft that are too small [29, 30].
In the beginning, landmarks were the only way for pilots to safely navigate. The
pilot had to see other airplanes in order to avoid collisions. Clouds, fog, and other
weather conditions restricted a pilot’s sight. Therefore, safe flying required that
limits of visual conditions had to be established.
Airport operating minima expresses the weather limits of the usability of an
airport for takeoff, landing in a precision approach, or landing in a non-precision
approach. The terms used are ‘‘visibility’’ or ‘‘runway visual range’’, ‘‘decision
altitude’’ or ‘‘minimum descent altitude’’, and, if necessary, ‘‘cloud condition’’ [31].
Each participant, the airport, the airplane, and the pilot has its own minima.
Airport minima depend upon the available approach facilities. Aircraft minima are
based on on-board equipment. The personal minima of a pilot are determined by
his experience. The least favorable of these minima should be applied in practice,
including any increments required due to system failures.
Flight rules play an important role in planning and carrying out fuel efficient flight,
for example through eliminating uncertainties that would otherwise increase the
need for surplus fuel. There are visual and instrument flight rules; see Table 14.3.
There are still minimum conditions and limits which must prevail so that
takeoff or landing can be legally initiated. These conditions and limits vary
according to weather conditions, location, and the height of terrain and obstruc-
tions in the vicinity of the airport, the available equipment of the aircraft, and the
qualification of the crew [35].
Key factors in alleviating, the load on the environment besides expediting traffic
flow are good control practices creating airspace design with airways as straight as
possible, and new concepts such as Free Route Airspace Concept for free flying
areas [36]. There are specific airspaces within which users can freely plan their
routes between an entry point and an exit point, without references to the ATS
route network. In these airspaces, flights remain subject to ATC. Consequently and
14.2 Navigation in Aviation 217
independently from the routes inserted in flight plans, it can become common
practice to offer aircraft operators the shortest routes.
Eurocontrol Airspace Concept ECAC includes:
• The ‘‘packaging’’ of en route and terminal routes, optimized trajectories, air-
space reservations, and ATC sectors into Airspace Configurations which are
designed and dynamically managed together to respond flexibly to different
performance objectives which vary in time and place; and
• Airspace Configurations activated through integrated collaborative decision-
making processes at national, regional Functional Airspace Block, and European
airspace network level reflected in the Airspace Network Management com-
ponent of the 2015 Airspace Concept [37].
The takeoff and the initial climb are the noisiest phases of a flight using the highest
power at the airport and in its surroundings. Takeoff usually starts at the beginning
of a runway with full thrust on the engines. If necessary, the thrust reduction is in
accordance with the actual takeoff weight. The climbing path and profile following
the takeoff can be optimized using modern navigation systems. The main phases of
takeoff and climbing are presented in Table 14.4 [38].
The takeoff thrust can be tailored to the actual conditions. The pilot sets lower
than the full thrust which the engine is able to deliver but enough thrust for safe
operation in the actual conditions. This measure can conserve engine life and
reduce fuel consumption and exhaust gas emissions and lower noise at and near
airports.
218 14 Navigation
There are noise abatements in practice for takeoff and climbing procedures. Many
airports publish departure routes indicating noise-sensitive areas along the flight path
with the corresponding altitude and routing restrictions for the airplanes [39].
Eurocontrol, the European Organization for the Safety of Air Navigation, esti-
mates that 1.5 9 106 t (3.3 9 109 lb) of fuel are still unnecessarily lifted into the
air every year because airplanes must be able to divert from their planned desti-
nation. About 1% of all European aviation emissions, corresponding to
14.2 Navigation in Aviation 219
0.63 9 106 t (1.39 9 109 lb) CO2 emissions per year, could be saved through
improved methods [43].
Improved coordination is required between civilian and military users con-
cerning the daily use of airspace blocks in order to avoid airspace congestion and
to increase fuel savings.
Through reforming flight navigation, airspace organization, and ATC, the
aviation industry could reduce fuel consumption by 15%.
In the European Union, the ‘‘Single Sky’’ initiative started in 2008. EU
researchers demonstrated new technologies on a large scale within the SESAR
initiative. According to the aims of the Advisory Council for Aeronautics Research,
the fuel consumption and the CO2 emissions in European aviation should be
reduced by 50% by 2020 compared with the year 2000. NO and NO2 emissions
should be lowered by 80% and noise output by 50% [44].
Shipboard Routing Assistance (SRAS) increases the safety of the ship and reduces
the risk to the ship and its cargo. With SRAS the officers on the bridge can
220 14 Navigation
The world’s oceans are divided into 16 areas of responsibility for broadcast pur-
poses called either Metareas for meteorological information or Navareas for
navigational warnings. The Area Meteorological and Oceanographic Coordinator
(AMOC) and the Supporting Service must provide [57]:
• Basic meteorological forecasts; and
• Warnings tailored for specific areas.
The service may also include:
• Basic oceanographic forecasts for the concerned areas;
• Observing, analyzing, and forecasting of meteorological and oceanographic
variables required as input for models describing the movement, dispersion, and
dissolution of marine pollution; and
• Operating these models and accessing national and international telecommu-
nication facilities [58].
This information may be prepared by AMOC, another supporting service or by
a combination of both. The authority responsible within the designated Marine
Pollution Incident must receive information about the location and details of any
marine pollution or emergency response operations [59].
Exhaust gas emissions and fuel consumption do not yet belong to the control
parameters of AMOC. However, the rising prices of marine fuel and the height-
ened emission regulations could lead to the measurement and reporting of both
parameters [62]. An electronic Fuel Marine Monitoring device could discover
deteriorations, wear in the combustion, in the exhaust gas after treatment system,
in the auxiliary devices, and also in the propulsion, regulation, and steering system
and send the message to the ship’s owner so that management can reduce fuel
costs and increase the operational efficiency [63].
Figure 14.8 presents the main elements of ship’s navigation.
Road traffic uses telemetry to continuously organize traffic flow. Navigation sys-
tems have electronic, magnetic, or optical sensors and wires installed in mea-
surement and operating equipment.
14.4 Summary and Recommendations 223
satellite
DG
PS
MPI, FMM
coastal
station
ship with telecommunication
equipment
Sensors installed in roads and on vehicles communicate with each other. Data
can be sent via GPS, Global System for Mobile communication, and Short
Message Service to a telemetry center controlling the traffic.
The combination of on-board sensors with satellite systems is gaining influence.
Organization measures for the continuous flow of traffic, e.g., intelligent ‘‘green
wave’’ in variable road intersections and the introduction of environmentally
friendly road pricing and on-board measurement in traveling vehicles can improve
road navigation.
In the future wireless units could be built into vehicles and at traffic lights and
emergency call boxes along the road. Sensors in vehicles and at fixed locations, as
well as connections to wider networks, could provide information to drivers. The
range of radio links could be extended by forwarding messages along highly
frequented paths. Drivers could use this information to reduce the chance of
collisions, to avoid bottlenecks, and to decrease the rate of fuel consumption and
emissions.
Current airspace has a density four times higher than 20 years ago. Safe and
efficient flight has been gaining more and more importance. Starts begin with
224 14 Navigation
careful preplanning through taking data and information about the environment
and infrastructure into account. Inflight data exchange between the dispatcher,
pilot, and controller requires automated processes based on computer technology.
Traditional ATC practices need changes, i.e., good practices, in the first line:
• Allowing directs airspace designs with airways as straight as possible; and
• New concepts with free flying areas.
Optimal takeoff and climbing paths and CDA are key factors in alleviating the
load on the environment.
Radio and satellite navigation has brought about better position recognition and
tracking. With modern navigation, the advanced aircraft systems can optimize
flight profiles and provide even more benefits from computers.
Methods of ship navigation have greatly changed. New procedures enhance the
ability to complete the voyage and save fuel.
Coastal networks are established or are planned in Europe, North America as
well as South-East Asia, India, China, Korea, Japan, South Africa, and several
other countries. Similar networks are also planned along major inland waterways.
A coastal AIS will soon replace the current DGPS beacon stations. It will not only
provide frequent determination of position relative to geographic coordinates but
also report the hydrographic features in restricted waters.
Fuel consumption and exhaust gas emissions monitoring completed with other
operation parameters has become possible with GPS navigation in combination
with data transfer to route management centers.
References
1. Navigation. http://en.wikipedia.org/wiki/Navigation
2. Telematics. http://en.wikipedia.org/wiki/Telematics
3. Global navigation satellite system. http://en.wikipedia.org/wiki/Global_navigation
4. Az új szoftverrel nincs baleset Japánban. Népszabadság. 22 June 2009, Budapest
5. Hamburger Abendblatt, 19/20/02/2011, pp 42: So können Navigationsgeräte im Auto beim
Spritsparen helfen
6. Traffic Message Channel. http://en.wikipedia.org/wiki/Traffic_message_channel
7. Routing helps find the most efficient route, but navigation and mapping help the driver get
there. http://www.trucking.randmcnally.com/ctonline/assets/images/tridion/HDT%20TECH_
REPORT_July_tcm18-189521.pdf
8. Völlig verheizt. Trucker 08/2009, München, pp 3–44. ISSN:0946-3218. http://www.trucker.
de
9. Fuel economy-maximizing behaviors. http://en.wikipedia.org/wiki/Fuel_economy_maximizing_
behaviors
References 225
The air of the Earth can be divided into different layers, which are defined through
clear temperature differences. The two lower layers are important when referring
to climate change:
1. The troposphere, the layer with weather events and
2. The stratosphere, the layer above the troposphere [1].
The upper limit of the troposphere varies daily and mostly depends upon the
season and geographical latitude. In the area of the equator it is at an altitude from
16 to 18 km (from 52,459 to 59,016 ft or 9.94 to 11.19 mi), at the poles it is from 8
to 12 km (from 26,230 to 39,344 ft or 4.97 to 7.46 mi). In the tropopause between
the troposphere and the stratosphere the temperature is approximately -60C
(-76F). The ozone O3 layer is in the stratosphere at an altitude from 25 to 30 km
(from 81,967 to 98,361 ft or 15.5 to 18.6 mi) [2].
The climate has been rapidly changing because of the rise in the concentration
of CO2 and other Green House Gases (GHG) in the atmosphere. Global warming
on the Earth is the result of emissions of CO2 and other climate changing gases [3].
CO2 is the most important Green House Gas that originates from the burning of
hydrocarbons, decomposition of biomass, e.g., from plants as well as from the
respiration processes of humans and animals. The combustion of 1l (0.264 gal (US)
and 0.220 gal (UK)) of gasoline produces 2.33 kg (5.14 lb) of CO2. The combus-
tion of 1 l of diesel or kerosene emits 2.64 kg (5.82 lb) of CO2. The concentration
of CO2 in the air is currently 370 ppm and increasing. CO2 remains in the atmo-
sphere for approximately 100–200 years, depending on the concentration [4].
The worldwide CO2 emissions increased from 22,500 9 106 t (49,606 9 109 lb)
in 1991 to 30,892 9 106 t (68,108 9 109 lb) in 2009. Despite the economic crisis
between 2007 and 2010, the average worldwide emissions increased and will
continue to rise in the next few decades. On the other hand, CO2 emissions have
declined in many countries because of the economic crises in recent years [5].
Water vapor, H2O, is the most important greenhouse gas beside CO2. Without
the naturally originating vapor from water, the Earth’s surface would be approx-
imately 20C (68F) colder. Unlike CO2, the water vapor emissions caused by
humans are too small in relation to the natural evaporation on the Earth to influ-
ence the climate [6, 7].
Natural sources of nitrogen oxides, such as NO, NO2 and other nitrogenous
substances, are caused by lightning and microbes in the ground. However,
improvements in fuel efficiency have been achieved through the development of
modern internal combustion and jet engines, which operate at higher temperatures
and higher pressures than in the past. Unfortunately these improvements also increase
the formation of nitrogen oxides, which can be reduced through further changes in the
combustion chamber or in an appropriate exhaust gas after treatment system [8].
Unburned hydrocarbons, HC, are mixtures of several hydrocarbons which
remain after incomplete combustion processes. The concentration of HC emissions
depends on the load of vehicles, airplanes and ships. HC is a climate gas with a
GHG factor that is three times higher, than CO2. At ground level, they contribute
to the formation of summer smog [9].
Ozone, O3, is a three-atomic oxygen molecule. At ground level, ozone is a
component of dangerous summer smog. At higher altitudes of the stratosphere, O3
molecules filter dangerous UV radiation [10].
While road and maritime transportation contribute to the summer smog near
ground level, aviation contributes to the ozone hole in the stratosphere. Pollutants,
such as NO2 reduce O3 concentration at ground level and lead to highly dangerous
and unhealthy situations, initially in big cities. Smog decreases the O3 concen-
tration at the poles by 2–4% in the winter and 4–8% in the summer.
Sulphur dioxide, SO2 molecules are dangerous to human health and form acid
rain. In addition, SO2 is an important aerosol creator and lowers the temperature of
the atmosphere through dispersion of sunlight. The climate role of SO2 is not yet
completely clear [11].
Transportation will grow very intensively over the next few decades in com-
parison to other sectors of the economy, especially in the rapidly developing
countries; see Fig. 15.1 [12].
The most meaningful international goals are:
• Increasing independence from fossil fuels;
• Decreasing climate gas emissions;
• Minimizing the cost of alternative fuels;
• Increasing the efficiency of road vehicles, airplanes and ships;
• Supporting new financial investments; and
• Creating new jobs for climate protection.
15.2 Interaction Between the Climate and conomy 229
35
10
5
0
2000 2005 2010 2015 2020 2025 2030
year
Fig. 15.1 Total Green House Gas emissions in developed and developing countries
In the past, industrial production influenced the climate, but the relationships have
changed and climate change is very intensively influencing transportation today.
There is a clear interaction between both systems; see Fig. 15.2 [13].
CO2 emissions from transportation have an impact on the climate and pollutants
have an impact on the environment, and the human and the animal health. In
contrast to solids and liquids, gases mix their substances very fast. The long
decomposition time of GHG substances of approximately 100–200 years leads to
the homogenous mixing of gases in the air. Exhaust gases from vehicles and ships,
which are emitted at ground level, also impact higher atmospheric layers [14].
230 15 Climate and Environmental Protection
Table 15.1 Regulation of emissions of Green House Gases in road traffic in the world
Country Regulation
China China introduced limits on CO2 emissions in 2005, 2008, 2009, and 2011 to protect the
environment [15]. The Chinese regulations limit vehicle weight. High performance
vehicles with high fuel consumption will not be sold in China in the future. Next
steps are China 4 for self-ignition engines (gasoline propelled engines have been
regulated in 2011) and China 5 in 2012
Japan In June 2010, the Japanese government started a study of further CO2 requirements for
2020. Each manufacturer has to achieve fuel efficiency as a weighted average in
each weight class. Consumption has been determined on 10–15 and FC08 test
cycles. New Regulation 2015 Fuel Economy will consider diesel and gasoline
vehicles together [16]
USA Moderate Corporate Average Fuel Economy standards are valid for fleet consumption.
Energy Independence & Security Act of 2007 estimates introduction of renewable
fuels and consumer protection [17]. EPA and NHTSA proposed new fuel economy
and GHG regulations for vehicles in 2009. Progressive proposals such as the
SULEV 20, SULEV 50, and SULEV 70 to update them are being advanced by the
CARB [18]. This regulation was valid for private vehicles, with less than 12 people
and achieved a reduction in CO2 emissions from 205 g km-1 (7.231 oz km-1 or
11.635 oz mi-1) in 2000 to 180 g km-1 (6.35 oz km-1 or 10.217 oz mi-1) in
2008. The agenda is to lower the CO2 output to 125 g km-1 (4.409 oz km-1 or
7.094 oz mi-1) by the year 2020. Light Duty Trucks (LDT B 8,500 lb (3.8 t)) emit
about 250 g km-1 (8.818 oz km-1 or 14.188 oz mi-1) presently. By 2020, that
should be reduced to 200 g km-1 (7.055 oz km-1 or 11.351 oz mi-1)
EU European legislation requires decreasing fuel consumption and CO2 output [19]. The
middle performance category of private vehicles in the EU produces about
159 g CO2 km-1 (5.608 oz km-1 or 9.023 oz mi-1) with an average consumption
of 6.6 l 9 100 km-1 (42.73 mpg (US) and 35.61 mpg (UK)). CO2 emissions are
limited to 130 g km-1 (4.586 oz km-1, or 7.379 oz mi-1) in 2015. 65% of the fleet
of cars must meet the requirement by 2012, 75% by 2013, 80% by 2014, and 100%
by 2015. After 2015, it should be decreased to 120 g km-1 (4.233 oz km-1 or
8.811 oz mi -1) and to 95 g km-1 (3.351 oz km-1 or 5.392 oz mi-1) by 2020. The
decision about how to reach the objectives for 2020 must be prepared in 2014
CO2 emissions depend firstly on the weight and the power of vehicles and sec-
ondly on the driving behavior of drivers and the traffic organization. Therefore,
many governments regulate the weight and emissions of vehicles. Yet these
standards are not easily comparable, due to differences in policy approaches, test
drive cycles and units of measurement.
The relevant stringency and implementation years of fuel economy and GHG
emissions standards in the world are in Table 15.1.
15.3 Climate Protection in Road Transport 231
100
50
0
500 1000 1500 2000 2500 3000
vehicle weight [kg]
impact [%]
NOX
50
20
0
0 2 4 6 8 10 12 14
altitude [km]
A trip from Europe to the east cost of the USA emits about 674 kg (1,485 lb) of
CO2 per passenger (between Hamburg and New York). Aviation is responsible for
2.4% of the global CO2 emissions, but consumption and CO2 emissions will
increase to 3 or 4% in 2050, in spite of expected improvements in the SFC [25].
The accelerated introduction of more modern aircraft would reduce emissions
per passenger-kilometer. Other opportunities arise from the optimization of airline
15.4 Climate Impact of Aviation 233
altitude [km]
55/45
8 hydrogen
kerosene
6
4 95/5
0
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5
factor for relative greenhouse effect
4908 38
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vgorgtcvwtg"qh"ugc"uwthceg"]£E_ 4907 36
4906 34
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4905 32
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4903 8
4902 6
480; 4
480: 2
3;52 3;62 3;72 3;82 3;92 3;:2 3;;2 4222
{gct
Fig. 15.6 Connection between temperature of the ocean’s surface and frequency of tropical
cyclones
The Earth’s atmosphere absorbs 7% more humidity close to the surface per degree
of warming. Feedback from local wind can increase humidity by up to 14%. This
process leads to more tropical storms over sea and land, like hurricanes, cyclones
and tornados; see Fig. 15.6 [30].
Wind velocities can reach 500 km h-1 (311 mph). Extreme precipitation events
appear more frequently. In the northern hemisphere, the number of short, extre-
mely intensive downpours is increasing. In summary, the number of storms is
constant, but the number of severe storms with lightning strikes is increasing; see
Table 15.2 [31].
Climate change strongly influences aviation. Cumulous clouds reach altitudes
of 15–16 km (49,180–52,459 ft, i.e., 9.3–9.9 mi) with different electrical charges.
Because of the wide area and the high altitude of storm clouds, airplanes flying in
these air corridors do not have any possibility to fly over these zones.
Positively charged lightning is dangerous even several km from the actual
thunderstorm zone at an altitude from 11 to 12 km (from 36,066 to 39,344 ft or
from 6.8 to 7.5 mi). Their temperature is 30,000C (54,032F) in the lightning
channel and their strike velocity is 100,000 km h-1 (62,150 mph). Although only
5% of all lightning is positively charged, it is more dangerous than negatively
charged lightning because it has particularly intensive discharges with consider-
ably higher current intensities and longer time intervals [32].
Some composite airplanes also have an additional layer of protection against
lightning strikes by installing Metal Oxide Varistors (MOV) throughout the circuit.
If an MOV senses a sudden surge of current than it is designed to break and protect
the rest of the aircraft’s delicate electronic systems [33]. Aircraft design principles
15.4 Climate Impact of Aviation 235
Maritime shipping emitted approximately 843 9 106 t i.e., 1,859 9 109 lb CO2 in
2009 and therefore contributed to 2.8% of anthropogenic CO2 emissions. In
comparison, aviation presented a similar—if slightly smaller—annual emission
rate with 733 9 106 t (1,616 9 109 lb) CO2 [34].
Sea-going vessels consume fuels with a sulfur content of 2–3% and annually
emit (10–12) 9 106 t i.e., (22.03–26.45) 9 109 lb SO2 into the atmosphere. The
production of SO2 is the reason that ships’ emissions have a disproportionally high
absorption of infrared radiation. According to the IPCC predictions, CO2 emis-
sions in maritime shipping will increase by factors of 1.1–1.3 up to 2020 and by
factors of 2.4–3.0 up to 2050. They are the most powerful rates of increase in
transportation; see Table 15.3 [35].
In inland navigation, ships often use higher quality fuels, i.e., diesel fuel.
Table 15.4 shows the current and future proportions of fuel consumption and
emissions in inland shipping [36].
236 15 Climate and Environmental Protection
Table 15.5 Dependence of fuel consumption and emissions in maritime shipping on economy,
transport efficiency and energy demands
Categories Variables Related elements Unit
Economy Demand Number of inhabitants, (t mi) year-1
local, regional and
global economic growth
Transport Efficiency depending on Ship design, propulsion MJ (t mi)-1
efficiency fleet composition, ship advancement, vessel
technology and speed, environmental
operation regulations, trade with
GHG emissions
Energy demand Carbon content in navy fuel Cost and availability of g (MJ)-1
fuels, use of residual
fuels, distillates,
biogenic fuels or other
fuels
Fuel consumption and emissions of fleets are determined by the economy, the
transport efficiency and the energy demand of ships; see Table 15.5 [37].
Predictions have to consider all factors. For shipping technology, despite the
greatest care, predictions contain inaccuracies and uncertainties.
Fuel consumption and CO2 emissions of large two stroke marine diesel engines
can be examined at a test bench. In artificial conditions at a test bench, Best
Specific Fuel Consumption (BSFC) corresponds to single operating points. The
real SFC in operation is expected to be 10–15% higher than in test measurements,
because:
• An engine does not always operate at its best operating point;
• The energy content of its fuel may be lower than that of the test bench fuel
(residual fuels typically have heating values which vary ±5%); and
15.5 Climate Impact of Shipping 237
• SFC values are given also with ±5% tolerance because of engine wear, ageing
and sub-optimal maintenance of fuel injectors and injection pumps, deterioration
of the propeller, defects in the turbocharger, increased filter resistances and wear
and tear of the heat exchanger.
The SFC of the main engine depends on the performance of the engine; see
Table 15.6 [38].
The fuel consumption depends on a number of parameters including average
load, number of speed variations, chosen route, wind and rain, waves, degradation
of the hull and drag of the ship.
All ships use residual fuel and need it to power different engines and equipment
on-board. When the ship is at sea, the heat is taken from the exhaust gas through
the steam boilers and hence no additional fuel is consumed. In port, the main
engine does not run and the ships need auxiliary engines and boilers using extra
fuel to generate heat.
The SFC of auxiliary engines primarily depends on the power they need; see
Table 15.7 [39].
The average calculation of a ship’s economy includes the auxiliary engine’s
fuel consumption although the load and operating hours of auxiliary engines
greatly varies between types of ships. This is especially true in tankers, where heat
is required for cargo heating, pumping, and the energy supply of auxiliary
equipment. Fuel consumption of auxiliary equipment in tankers can be 20–25% of
the whole consumption.
238 15 Climate and Environmental Protection
Table 15.8 shows the boiler fuel consumption for auxiliary equipment in
tankers [40].
Air-conditioning requires a performance of approximately 5.0–10.0 W (6.8–
13.6) 9 10-3 HP per 1.00 kW (1.36 HP) of the main engine power on an average
merchant vessel. With the increase in average air temperature because of climate
change, also the costs of air-conditioning and perishable goods’ cooling in shipping
will increase [41].
In accordance with legislation, all parts of road vehicles, airplanes, and ships have
to be recyclable by up to 90–95%. Besides traditional materials for building
15.6 Recycling and Climate Balance of Transportation 239
Design for recycling Resin recycling and Replacing and re- Battery recycling
reuse manufacturing parts system
Use of recycled
materials
vehicles, such as steel and aluminum, light plastics, composite, and fiber glass
strengthened materials are increasingly used and recycling them requires a specific
technology; see Fig. 15.7 [42].
Light construction plastic materials on average require a higher level of energy
in the production process than considerable metal products. That is the reason why
plastic elements of road vehicles, airplanes, and ships are usually difficult to
recycling and need a very long time to decomposing. There are still a lot of open
questions for future development in production and recycling of light construction
materials.
As airplanes are very expensive, most of them are typically leased for 20–40 years.
Very few go back into service after a long lease because evolving aerospace
technology leaves older airplanes unable to compete against newer airplanes,
which can be operated at a lower cost with decreased fuel consumption.
To protect the environment, professional decommissioning and recycling of
older aircraft will increase in the future. There are no regulations for recycling
airplanes. Many of them stay in the desert. Expensive equipment for aircraft, e.g.,
navigation and safety devices are often collected and utilized in special second
uses [43].
The self-obligation of aviation companies is moving in the right direction.
Many of them wanted to realize 50% recycling or more. In the future, legislation
should be similar to cars and 90–95% of all parts of an airplane should be recycled.
240 15 Climate and Environmental Protection
An agreement for safe and environmentally friendly recycling of ships has a lot of
unanswered questions. Ships from member states will only be allowed to be
scrapped if basic environmental and climate protection rules are in force. Cur-
rently, there are only some countries which have specialized reglementations in
cutting up ships. Similar to aviation, the environment and ecology need common
legislation for the recycling of ships.
Steel plays an important role in maritime shipping. Steel is the most important
construction material and it is particularly close to nature. No other material has
such a closed circuit and can be recycled so often without losing its quality. In the
long run, the demand for new steel types remains high. Annual steel consumption
will probably increase by 40% within the next 10 years. This tendency will
determine recycling technology in future ships [44].
The amount of CO2 emitted from all means of transportation depends on the type
of fuel. Certain fossil fuels contain more carbon per energy output than biogenic
and synthetic fuels and hence produce more CO2 emissions per unit of work done.
Although future scenarios contain positive assumptions about biogenic and
synthetic fuel use, the market penetration of individual fuels shows the leading role
of fossil fuels between 2020 and 2050:
• Petroleum or gasoline will remain the most important energy source supplying
from 16 to 28% of the world’s primary energy demand; and
• Mineral oil and natural gas products as fuels will contribute to the transportation
from 57 to 82%.
The Kyoto Protocol, Annex I, Article 2.2 made requirements for the reduction
of the emissions of climate gases in 1997. Members of the United Nations
Framework Convention on Climate Change (UNFCCC), a sub-group of the UN,
take the necessary actions in two ways:
• Controlling emissions in national regulations. The precise accounting of fuel
consumption is a good indicator of the real activity; and
• Setting targets for all sectors of transportation and developing global and
regional policies within a limited time according to the UNFCCC review.
15.7 Summary and Recommendations: Climate Protection in Transportation 241
Road transportation emits approximately 3,500 9 106 t i.e., 7,717 9 109 lb CO2
in the atmosphere yearly. This is approximately 0.2% of the absolute CO2 content
of the atmosphere.
The pace of change in road transportation strongly depends on the price of oil.
Vehicles emit the highest amount of GHGs such carbon dioxide and other sub-
stances, which negatively influence the climate and the environment.
Besides regulations, the following measures can effectively reduce fuel con-
sumption and emissions:
• Widespread use of sensor, actuator and computer technology, data communi-
cation, stream lining, heat insulation, engine efficiency, light weight construc-
tion, etc.;
• Increasing driving efficiency with improved navigation;
• Financially right and socially well-balanced introduction of climate protection
measures, e.g., taxes;
• Reducing the transport demands between work and residences;
• Reorganization of districts for work, residence, and recreation in cities;
• Improvement of conditions in mass transportation; and
• Decreasing the costs of public transportation.
Changing the awareness of people depends more on motivation than on tech-
nology. Programs can teach drivers to save fuel and protect the climate.
Trends of gas and noise emissions in commercial aviation show that CO2 emissions
will rise from the recent level of 733 9 106 t i.e., 1,615 9 109 lb to 1,480 9 106 t
i.e., 3,264 9 109 lb by 2025. NO and NO2 mass is expected to grow from
2.5 9 106 t i.e., 5.513 9 109 lb in 2000 to 6.1 9 106 t i.e., 13.40 9 109 lb by 2025.
Aviation intensively influences the climate because jet airplanes fly at high
altitudes near the tropopause and emit particles and gases, and leave contrails.
Both can increase cirrus cloud formation. Airplanes can also release chemicals that
interact with GHGs in the atmosphere. Nitrogen compounds are particularly
dangerous, because they destroy ozone molecules at high altitudes.
Emissions from passenger aircraft vary per passenger kilometer, according to
the size of the aircraft, the number of passengers on-board, and the cruising
altitude. The rule of thumb shows that the average level of emissions depends on
the distance of the flight:
• Short-haul airplanes on flights under 463 km (288 mi) or under 3 h emit
approximately 259 g km-1 of CO2 (9.1 oz km-1 or 14.71 oz mi-1);
242 15 Climate and Environmental Protection
• Mid-haul airplanes on flights over 463 km (288 mi) up to 3,000 km (1,863 mi)
or between 3 and 6 h emit 178 g km-1 of CO2 (6.28 oz km-1 or 10.1 oz mi-1);
and
• Long-haul airplanes on flight over approximately 3,000 km (1,863 mi) or more
than 6.5 h emit 114 g km-1 CO2 (4.02 oz km-1 or 6.47 oz mi-1).
The SFC per passenger and kilometers in aviation is approximately 130–140 g
(4.59–4.94 oz) and similar to the emissions of a car with four seats and one person
on-board. New developments may produce emissions lower than 100 g (passenger
km)-1, i.e., 5.68 oz (passenger mi)-1 for very large jet airliners.
Currently, the taxiing noise level of most Western aircraft is between 123 db(A)
and 133 db(A). Specific noise level of airplanes is decreasing in course of new
technologies in aviation. However, the average noise emission level near terminals
of airports will increase from 24 dB(A) in 2000 to 30.3 dB(A) by 2025 due to the
higher air traffic.
Currently, ships emit less than 1,000 9 106 t i.e., 2,205 9 109 lb of CO2 each
year. Emissions have grown more than 85% since 1990, the base year of the Kyoto
Protocol. Predictions show that global fuel consumption and CO2 emissions of
ships will increase continuously and will be 160–284% higher in 2050 than in
2009. However, new technologies can decrease ships’ fuel consumption and
emissions.
Short-term goals are slow steaming and optimal use of existing technologies
and resources. Long-term goals require new technologies, particularly the use of
renewable energy sources in ships. These measures require not only new tech-
nology but also new international and national laws. Scenarios predict an increase
in maritime emissions of 75% by 2020. The reason is the expected growth of the
world trade fleet, which cannot be balanced with improved SFC of new vessels.
UNFCCC has the goal to reduce emissions from ships by 40% by 2020 and by
80% by 2050. New propulsion systems are needed, which could reduce emissions
from ships by 10% and improved operations, which could reduce them by another
10%.
References
1. Troposphere. http://en.wikipedia.org/wiki/Troposphere
2. Stratosphere. http://en.wikipedia.org/wiki/Stratosphere
3. Ozone layer. http://en.wikipedia.org/wiki/Ozone_layer
4. Global Warming. http://www.library.thinkquest.org/CR0215471/global_warming.htm
5. CO2 Emissions. http://www.sunearthtools.com/dp/tools/CO2-emissions-calculator.php
References 243
37. The environmental impacts of increased international maritime shipping—past trends and
future perspectives. http://www.oecd.org/dataoecd/32/43/41750201.pdf
38. Marine Engine. IMO Tier I, Programme 2009. http://www.doosan.com/doosanengine/
attach.files/cp.pdf/Doosan-MAN01.pdf
39. Adamkiewitz A, Kolwzan K, Marine power plant pollutant emissions. http://www.docstoc.
com/docs/22791237/1-MARINE-VESSEL-MISSIONS
40. Tankers. http://www.scribd.com/doc/37400636/Tankers
41. Aframax Tanker saves 283 MT fuel oil, ($82,000) in single voyage. http://www.network.
tankeroperator.com/profiles/blogs/aframax-tanker-saves-283-mt
42. ACEA agreement. http://en.wikipedia.org/wiki/ACEA_agreement
43. Aircraft and Composite Recycling. http://www.boeingsuppliers.com/environmental/TechNotes/
TNdec07.pdf
44. World Shipping Council (2009) The liner shipping industry and carbon emission policy. Sept
2009. http://www.apl.com/environment/documents/20091006_Emissions_Policy.pdf
Chapter 16
Transportation Costs
The transportation especially strictly depends on production conditions of the oil industry.
Strategy in fuel production has to be considered in transportation planning [1]. Since 1980,
the discrepancy between oil production and new discoveries has increased (see Fig. 16.1).
The linear extrapolation of the recent fuel consumption of approximately
4,700 9 106 t i.e., 10,362 9 109 lb per year predicts an increase to approximately
5,000 9 106–6,000 9 106 t i.e., 11,023 9 109–13,228 9 109 lb per year in world
oil consumption in the next years. This tendency should lead to the consumption of
the half of all oil reserves on the Earth by 2030. The total CO2 emissions would
probably grow from the current level of 14,000 9 106–16,000 9 106 t i.e.,
30,867 9 109–35,276 9 109 CO2 per year to approximately 25,000 9 106–
30,000 9 106 t i.e., 55,119 9 109–66,143 9 109 lb per year in 2030 [2].
The costs of fuels are very unevenly distributed on the Earth (see Fig. 16.2).
Unbraked development would require lower fossil fuel prices on the world [3].
Apart from single processes, the global growing tendencies in fuel price level are
110
100
oil [10 barrel*day ]
-1
90
need of mineral oil
80
production of mineral oil
70
6
60
50
40
2005 2010 2015 2020 2025 2030
year
180
160
140
price [cent*litre ]
-1
120
100
80
60
40
20
0
France
Spain
Brasil
Australia
Canada
India
Russia
USA
China
Algeria
Singapore
Norway
Germany
South Africa
Saudi Arabia
Venezuela
very similar. The example of Germany shows the typical changes in the price of
fuel in the last decades (see Fig. 16.3).
An acceptable petrol reduction can be achieved by using pure biogenic fuels of
the first generation, such as alcohols and FAME, but at a substantially higher cost
level than consuming conventional fuels (see Fig. 16.4) [4].
Second-generation biogenic fuels promise to be cheaper but the technology is still
under development and only a few countries such as Brazil use them. The amount of
fuel that can be produced is limited by the amount of crops that can be grown.
Biogenic fuels can be produced at lower prices in the future. In the long term,
the most economic solution is the production of BTL, but it requires new inno-
vations and a high level of research. On the other side, excessive use of biogenic
fuels could endanger the world’s agricultural areas because of the increasing use of
pesticides and artificial fertilizers on industrial produced monocultures.
16.3 Prices of Measurement Technology 247
1.6
price [Euro*litre-1]
1.2
0.8
0.4
petrol diesel
0
1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010
year
800
600
fuel costs [%]
400
200
0
petrol diesel LPG CNG alcohols CTL FAME BTL H 2 (NG) H2 (wind)
kind of fuels
When automobiles were first produced they had large engines with low rpm and
heavy construction with long durability and an extremely high price. Later mass
production led to low prices of cars and all social classes could buy them. In 1957,
a Fiat Nouva 500 cost DM 2,650, in 1970 a 500 Luxus cost DM 3,850, and
currently the new Fiat 500 costs €11,300 [7].
The price situation of cars, depending on size, performance, and special
equipment is presented in Table 16.1 [8].
Electric cars will only sell after the battery price drops to about €5,000, i.e., US
$7,150. Some manufacturers are planning to rent rather than sell future electric
cars or the battery to avoid the high cost of purchasing one [9].
The cost of automobile transportation, particularly fuel cost, will generally
increase in the future (see Fig. 16.5).
16.4 Costs in Road Mobility 249
300
price of maintenance
250
price of fuel
purchase price
200
change [%]
150
100
50
0
1990 2000 2010 2020 2030
year
Small, cheap, and fuel-efficient vehicles are advancing fast. Low-cost models have
become a new market segment. The upper financial limit of purchase depends on
personal incomes in each region [10].
Retrofitting fossil fuel engines with natural gas combustion adds on average
€280–300, i.e., US $300–329 to the list price of a car with a spark ignition engine
and adds €680–900, i.e. US $972–1,287 to the list price of a car with a diesel
engine. Higher purchase prices usually amortize after 2–4 years. The surcharge
depends on the price of fossil and gas fuel [11].
Vehicles influence health by noise, exhaust gas and particle emissions, and acci-
dents. However, the risk of traffic accidents is usually lower than the risk of an
accident in the home.
In highly developed countries, traffic is increasing while fatal accidents are
decreasing. In developing countries, most accidents are caused by poor planning,
inadequate design, old infrastructure, and lack of driver training. Efficient emer-
gency services are needed to reduce the severity of accidents [12].
WHO estimates that approximately 1.3 million people are killed and more than
50 million people are injured in accidents each year. Transportation safety is very
problematic in some developing countries with more than seven fatalities per 1,00
thousand million km, i.e., 4.35 fatalities per thousand million mi. Countries which
250 16 Transportation Costs
8.0
HL
fatalities per 109 travelling km
6.0
level education
HL
4.0
2.0
0
2000 2005 2010 2015 2020
year
HL: High Losses (Developing countries)
LL: Low Losses (Scandinavian countries)
have the best infrastructure, present the highest safety on roads with 3.5 fatalities
per thousand million km, i.e., 2.17 fatalities per thousand million mi (see Fig. 16.6).
Lead emissions have been successfully reduced. Calculations show a positive
trend, thanks to the increasing introduction of lead-free fuels. The forecast is less
favorable for other pollutants because the total number of cars is increasing and
emission controls which are technically possible have not been universally
adopted. Outside Europe and Japan, people do not treat noise as a health risk
despite the increasing standard of living.
One of possible ways is the increasing intelligency of road vehicles. Self-
diagnosis provides visible results on-board. Visualization of dynamic driving
character in driving schools can contribute to an improvement in driving behavior
and to a long-term improvement in traffic safety.
Reducing fuel consumption limits climate change. Efficient cars are important for
saving energy. They can reduce the dependence on oil imports and its associated
geopolitical risks [13].
The estimation of the speed of climate change over time is the biggest unsolved
problem of climate predictions. Newest environmental conceptions require CO2
limits for new cars at 120 g km-1, i.e., 4.23 oz km-1 or 6.81 oz mi-1 by 2012,
80 g km-1, i.e., 2.82 oz km-1 or 4.54 oz mi-1 by 2020 and 60 g km-1,
i.e., 2.12 oz km-1 or 3.408 oz mi-1 by 2025. Further requirements are penalties of
€150, i.e., US $214.5 for each surplus 1 g km-1, i.e., 35.3 9 10-3 oz km-1
16.4 Costs in Road Mobility 251
or 56.8 9 10-3 oz mi-1 for additional CO2 emissions, with no exceptions for
small-volume car manufacturers and no credits or incentives for cars that can run
only on mixtures of fossil and biogenic fuels, or CNG or LPG without absolute
decreasing SFC [14].
Airplane operating costs are a crucial sales argument for the airlines besides safety,
comfort, and environmental friendliness. This economic calculation includes
direct, indirect, and total operating costs.
Modern airliners are designed for a life span of approximately 20 years and 60,000
Flight Cycles, i.e., landings [15].
The sequence of development of airplanes can be divided into phases of
research and construction, preparation, and mass production.
These main stages have several smaller phases, e.g., technical preproject to
define concept, building a prototype, carrying out a wind tunnel test, defining the
preconstruction, working out of details of construction and of production docu-
ments, constructing mock ups, system trials, structural test plans, realizing flight
tests for production, customized changes, technical improvements, and further
developments (see Fig. 16.7).
Airplanes are produced according to their production documents and manufac-
turing processes. Mass production comes after completion of the mock-up phase.
At first, the purchase price depends on production, i.e., on labor and equipment
costs; see Table 16.2.
Turboprop engine-driven short distance airplanes are very economic. The range
is very broad, and reaches up to €270 million, i.e., US $307 million. Table 16.3
shows the main technical data and price of modern airliners from the manufacturer
Embraer [26].
The Direct Operation Cost (DOC) is determined by the technical data of the
airplane. DOC can be divided into fuel costs (28.4%), costs of cockpit, and cabin
252 16 Transportation Costs
personnel (19.8%), landing and navigation fees for the airport and air traffic
control which correspond directly to the weight (15.6%), the maintenance costs of
the aircraft (8.8%) and of the engine (2.7%), the amortization (16.7%), the
financing costs (7.0%), and the insurance costs (1.0%). The last three parameters
directly depend upon the airplane’s price [28].
The DOC of a medium range, single-aisle airplane can be reduced up to 0.40%
by a 1% reduction in the SFC, up to 0.30% by 1% reduction in drag, up to 0.20%
by 1% reduction in weight, and up to 0.25% by 1% reduction in investigations
during development and production [29].
Experience shows that reducing the cockpit crew from 3 to 2 men saved
approximately 4% of the DOC. Further crew reductions are planned for freight
transportation. In civil aviation, two pilots will continue to remain in the cockpit in
the future.
Unmanned airplanes, so-called drones has become more important not only in
the military but also in the civil aviation for research, economy and ecology.
All new technologies in aviation aim to decrease the direct operating costs.
Using rebuilt or new jet engines with propfans is one of the best ways to decrease
SFC. A propfan is a modified turbofan engine with the fan placed outside the
engine nacelle and sitting on the same axle as the fan blades of a turbofan. It is also
known as Ultra High Bypass engine which requires an open rotor jet engine with
contra-rotating blades. The design is intended to offer the speed and the perfor-
mance of a turbofan, with the fuel economy of a turboprop [30].
16.5 Costs in Aviation 253
A propfan delivers 35% better SFC than contemporary turbofans, but it is very
noisy. Therefore, application requires further passive and active noise protection
measures which must also be included in the cost calculation. Military transporters
use propfans because of their low fuel consumption and high durability.
A ship’s prices depend on its complexity, i.e., on the propulsion, the engine, and
the auxiliary equipment, etc. Technology increasingly defines the costs of ships,
not only in the military but also in the civil shipping too (see Table 16.4).
254 16 Transportation Costs
About 40% of all merchant ships are bulk carriers. They range in size from
single hold mini-bulker to large bulk ships with DWT 365,000 t (359,252 ltn, i.e.,
804 9 106 lb) [44].
The most expensive parts of ships are the embedded electronic modules,
especially in navy ships. Therefore, submarines and aircraft carriers are the most
expensive ships on the world.
16.6 Costs in Shipping 255
The costs of operation per kilometer depend on the utilization of the capacity of a ship.
In public transportation, such as ferries, fuel consumption and emissions could be
reduced if it were possible to cancel trips that were under capacity. This measure could
increase flexibility of ship owners in planning routes but reduce passengers’ conve-
nience. In similar cases, airlines substitute smaller airplanes for larger ones [45].
New ships are more efficient than old vessels. The life cycle of ships is long. There
are a lot of vessels, which consume more fuel and emit more pollutants and noise
than newer types. Replacing old ships with new efficient models reduces fuel con-
sumption and emissions. However, the early scrapping of ships is a very complex
decision involving a variety of factors such as expected fuel prices, the market
forecast, the liquidity of the shipping company, and the expected capital return [46].
According to SOLAS, products of natural gas or biogenic gases are not allowed to
be used on ship as fuels because the flammability limit is below 608C (1408F).
Applications with gases without a special permission are not allowed because
special tanks are needed for liquified or compressed gas. Although LNG is
currently a cheap energy source, the drawback is that it needs high energy amounts
to be liquid and to be safely stored on-board in the ship. CNG needs twice the tank
volume than LNG.
The main reasons are
– The ship cannot travel far enough on one pressure-tank load; and
– The supply infrastructure is not sufficient.
Therefore, the best possibility to start using gas would be on ferries or vessels
with short voyages according to experiences in Norway. In inland shipping, the use
of LNG will rapidly gain high importance because of less pollution [47].
On sea, the introduction of gases as fuel is much more difficult, because of the
small energy density of gaseous fuels. Ships have to carry a large amount of CNG
to save the required performance [48].
LPG is heavier and less flammable than methane and burns at higher temper-
atures than CNG and LNG. The specific density higher than air requires special
safety measures on ships. Additionally, LPG is more expensive and available in
smaller volumes than CNG and LNG [49].
256 16 Transportation Costs
GTL and biogenic fuels are energy carriers of the future. The production
process of GTL consumes 40% of the energy contained in GTL. Biogenic fuels
can gain a role in in-city ferry routes or other short sea trades [50].
In the 70s and 80s, scientists expected, that hydrogen will gain a leading role in
the economy and ecology. However, currently, the dominant technology is steam
reforming or hydrocracking. Hydrolization, a specific way of electrolysis means
only a small portion of H2 production. On the other side, hydrogen requires
approximately six times the space of LNG. The fight and safe storage of H2 on
ships is yet a not solved problem.
Fuel price has become the most decisive factor in transportation. Unleaded gas-
oline costs on average €1.469, i.e., US $2.1 in the EU. The span ranges from
€1.212/l up to €1.662/l. The price of diesel has been intensively increased last
years. Recent price ranges between €1.205/l and €1.667/l. The average is €1.180/l
[51].
LPG has a ca. 60–70% lower price level. It costs approximately €0.8/l. The
span ranges from €0.578/l up to €1.229/l. CNG has the same specific price level
than LPG when the heating value per m3 or cu ft is converted to liter [52].
(UK). The newest very large airliners consume\3.0 l (100 km and passenger)-1 of
fuel, i.e., 78.4 passenger-mpg (US) and 94.1 passenger-mpg (UK) because they fly at
higher altitudes, i.e., above 40,000 ft (12,200 m) than conventional jet airplanes.
Similar to vehicle technology, a 10% reduction in the weight of airplanes leads
to about a 7.5% and a 10% reduction in air resistance leads to a 4–5% reduction of
fuel consumption.
Aviation technology is moving toward the intensive decreasing fuel consumption
and pollutions. However, changes in the combustion processes are part of the natural
aging of jet engines. Measurement and storage of the data of combustion products
can provide precise information about the burning quality and help to find the right
balance between the individual combustion chambers of the airplane.
A ‘‘life cycle’’ is the time interval from the beginning of the development to the
end of the service life of all transportation means. It is different for road vehicles,
airplanes, and ships. Life cycle assessment considers the following time intervals:
• Technology development, preliminary designation, and Type approval and Type
certification of road vehicles takes 3–5 years, of aircraft and of ships 5–10 years;
• Production run of road vehicles takes 10–15 years, of aircraft and ships 15–20;
and
• Operation of road vehicles takes 15–20 years, airplanes and ships 25–30 years.
The total cost of a ship, an airplane, and a road vehicle is influenced by a chain
of investments and events during the whole life cycle. The costs of development,
Type approval and certification procedures have to be compensated with incomes
during they service life.
16.8 Summary and Recommendations 259
The cost of car travel is rapidly increasing worldwide because of the rising cost of
fuels. To increase private mobility for all social classes, manufacturers have built
more and more fuel-efficient cars in the last decade.
The cheapest new cars in the world cost about €2,000, i.e., US $2,859. They are
mainly accepted in developing countries.
The future belongs to new technologies and new models, but only large
financial investments can support the introduction of new technology, such as
electric cars and new energy storage systems. Combustion engines will dominate
development and will have cost advantages for the next few decades. Electric
transport will remain at a relatively high cost level, including development,
production, and daily operation.
The Total Operation Cost (TOC) in air transportation is the sum of the Direct
Operating Cost (DOC) and the Indirect Operating Cost (IOC), which are usually in
a 100:80 ratio.
The direct operating cost can be reduced up to 4% by using high bypass ratios
in turbofan jet engines. Using propfan engines saves up to 5%: The construction of
a new type airplane with traditional ‘‘heavy’’ materials saves up to 1%, a new type
with ‘‘light’’ alloys up to 2%, and with plastic materials up to 4%. The best costs
saving, up to 12% of DOC would be from using ‘‘super light’’ composite materials
with nano tubes as filling in the construction and propfan jet engines in the
propulsion system. Rebuilding older jet engines in relatively new airplanes with
propfan technology can save up to 10%.
IOC is reservation, sales and advertising (34% of IOC), administration and
training (14%), fuel (35%), and dispatching (17%).
New technologies in aviation are expensive. High wing ratio and smooth, light
fuselage construction need new innovations, inventions, and high investment over
a long time. These measures have been effectively increased lift and decreased
drag of new airplanes, lower fuel consumption, and TOC in the last decades.
However, for economic reasons, relatively simple optimizations are in the most
cases more practical, that the total reconstruction of the aeroplane.
Relatively simple measures are
• Improvement of the aerodynamics of older airplanes;
• Use of winglets;
• Application of new aerodynamically optimized painting on the surface;
• Realize of weight reduction; and
• Introduction of new interiors.
260 16 Transportation Costs
The costs per ton or nautical mile are the lowest in maritime shipping. Larger ships
have lower costs. That is why ships in both ocean and inland navigation are
becoming larger.
The costs of ships similar to airplane’s cost structure can be divided into TOC,
DOC, and IOC. The TOC depends on type, construction, performance, and on
inbuilt electronic equipment. Technical measures to decrease TOC usually
improve the hydrodynamics and aerodynamics of ships in water and in the air and
improve engine, propulsion, and construction. Effective inspection and mainte-
nance generally save fuel and costs.
Port infrastructure and connection of ports to their hinterland with rail and road
networks also influence shipping costs.
Considering developing fuel prices and CO2 taxes, fuel consumption and
exhaust gas emissions must be lowered in the future. Improving maneuvering and
approaching routes near harbors and reducing waiting times at harbors also
increase economy.
Expected, that in the future, harbor fees will be partly based on exhaust gas
emissions. Not only CO2 emitted by combustion, but also hydrocarbons belong to
GHG. Optimal bunkering and refueling processes are also very important. Other
climate protecting measures come from using shore power in harbors for energy
and cooling. This is the ‘‘green’’ power source from land produced by electric
utility companies instead of the ship’s engines.
The problem is very similar to aviation. Airplanes must be supplied by GPU, a
specific type of ‘‘shore power’’, at airports. In the future, shore power can be
generated by renewable energy sources such as wind, solar, biomass, or geo-
thermal energy, depending on the local geography and infrastructure. However, the
price of renewable energy for this type of energy generation is still high. Common
taxation and promotion of shore power technology produced by renewable energy
is in development.
References
Instead of a quick revolution, new technologies will slowly evolve in all sectors of
transportation. However, customers worldwide need sustainable, high quality
transport at a reasonable price [1].
Figure 17.1 shows the expectations regarding properties of new transportation
systems.
Change in road transportation, aviation, and ship navigation requires a high
investment, a long time interval, and well-coordinated research activities world-
wide to turn to sustainability. There are several possible paths what will be ana-
lyzed in next paragraphs.
It is predicted that new technologies will make it possible to decrease the prices of
small cars to a reasonable level. Therefore cost-efficient and low performance
four-seat family cars will be increasingly used in both highly developed and
developing countries.
The trends indicate the largest growth rate to be in freight transportation in all
industrial sectors. The number of commercial vehicles is expected to increase by
about 55% in the next 20 years.
Downsizing the engine reduces the cubic capacity and the weight of the engine.
However, the use of a very high number of revolutions can increase fuel con-
sumption, especially in very small engines. Driving downsized engines in the best
speed and gear ranges without excessive braking and accelerations saves a high
amount of fuel and emissions [4].
It is possible to further downsize two- or three-cylinder engines with a Common
Rail system which operate in all ranges of load at the most favorable number of
revolutions especially in starting phases, which are highly sensitive against
irregular running in small highly downsized engines. Electronic control will more
and more support optimal operation in all ranges of number of revolutions and
under all environmental conditions.
Originally, the charging of piston engines was developed for aircraft engines to
compensate for the reduced air density at higher altitudes and to compensate for
the resulting reduction in the engine’s performance. The turbocharger is a special
device which forces more air and fuel into the engine. Unlike the compressor,
which is driven by the crankshaft, the turbocharger is driven by the exhaust gas.
Variable Turbine Geometry makes it possible to regulate the charger pressure to
a large degree. It is primarily used in self ignition engines due to the maximal
exhaust gas temperature of 700–800C (1,292–1,472F).
The exhaust gas temperature of turbocharged spark ignition engines can reach a
dangerously high temperature of 1,000C (1,832F) which is the usable limit of the
advanced materials. These new materials make it possible to use high level of
turbo charging as well in spark as in self ignition engines. Nowadays, for the
266 17 Future Transportation Systems
magnetic
coupling throttle
charged air
cooler
fresh air
crank-
waste gate
shaft
Fig. 17.2 Use of a positive displacement compressor in a four-cylinder spark ignition engine
Turbochargers can be started only when the engine produces sufficient exhaust gas.
The turbo lag in the first seconds of start is an unfavorable side effect of this
technology. Positive displacement compressors improve the engine response
without significant delays or turbo lags. They need a direct drive, which is taken
off at the crankshaft; see Fig. 17.2.
Positive displacement compressors usually run up to 2,000–2,400 rpm; the
turbocharger starts at higher rpm. Future compressors will need high temperature-
resistant materials, in the air intake as well, because they will operate with a higher
number of revolutions and therefore at a higher charge air temperature. Monitoring
emissions will become more important to achieve improved inspection and
maintenance under extremely raw operation conditions [6].
Engine performance due to fully loaded and optimized compressor technology has
increased by about 15% in the last years. However, the use of compressors also has
disadvantages, such as the higher fuel consumption and the delayed start of the
catalyst. The operation temperature of the exhaust gas after treatment system is higher
compared to the turbocharged system and an early aging of the catalyst is possible.
The combined use of a turbocharger and a compressor needs less space than
two turbochargers usually placed above the engine, because the turbocharger and
the compressor can be put between the cylinder heads. This construction has a
lower temperature in the engine compartment compared to two turbochargers.
A lower temperature with better aerodynamics partly compensates for the higher
fuel consumption.
17.1 Future Trends of Road Vehicle Technology 267
injection pump
EGR valve
Common Rail
piezoelectric injection
heat
exchanger
2.2.1 self ignition
engine with 4 in-line
cylinders
exhaust port injector
EGR cooler
air
filter pressure diference sensor
Fig. 17.3 Common Rail and exhaust gas after treatment system in a self ignition engine
Injecting pure fuel into the exhaust gas when congestion in the particle filter is
detected increases the temperature and leads to the combustion of the particles as
well as to the reduction to nitrogen oxides. A system that includes exhaust
recirculation is called Diesel Particulate Nitrogen Reduction (DPNR) which
eliminates the remaining CO, HC, NO, and NO2 emissions in downstream cata-
lysts. In this technology, no additional urea is necessary in contrast to the con-
ventional SCR technique [7].
Today, a common exhaust gas after treatment system consists of:
• SCR catalyst;
• NOx storage catalyst;
• DPNR catalyst;
• Oxidation catalyst;
• Particulate filter; and
• Appropriate sensors; see Fig. 17.3.
17.1.1.6 Heat Recovery and Noise Reduction in the Exhaust Gas System
The primary task of the exhaust gas system is decreasing pollutant concentration in
the exhaust gases.
The exhaust gas after treatment system of the engine discharges the exhaust
gases and also recycles energy, depending on the engine power. Air-borne noise
268 17 Future Transportation Systems
generated by the engine and from the exhaust gas system is harmful. The exhaust
gas after treatment system must also reduce noise by means of mufflers [8].
There are three basic methods to improve the efficiency of exhaust gas after
treatment systems:
• Improving particle diminution in the engine’s rough emission;
• Combining the particle filter with the NOx reduction catalyst; and
• Developing highly durable filters which can be frequently heated and
regenerated.
This technology has been successfully developed over the last years, but still
requires further investment, especially in heavy-duty vehicles and ships. In ships,
the system can also recover heat, in order to use a part of the exhaust gas energy
for preliminary fuel heating. An exhaust gas recovering system consists of a
recuperator that may be a steam generator or a distribution heater fitted to the gas
turbine or the self ignition ship engine.
Although hybrid technology is state of the art in the spark ignition passenger car
technology, the development will go more and more on in the self ignition and
heavy-duty technology. Self ignition hybrid in passenger car is state of the art.
In the far future, electric vehicle technology could be improved in a way that is
not yet imaginable. However, the rate of development is not sure. Recent expe-
riences have proven that new technology will develop slowly and not in a revo-
lutionary way. This includes the cost, safety, durability of the electric storage
battery, the supplying manufacturers with new raw materials, e.g., with lithium
and the recycling of all parts of the electric engine and the connected technology.
Hybrid technology means the common use of an internal combustion and usually an
electric engine for driving. Theoretically, many principles are possible for hybrids,
which can store and utilize the recuperated energy from braking, e.g., flywheel,
hydrostatic systems, compressed air, etc., but today the electric solution seems to be
the most viable way. Wide ranged applications for commercially usable vehicles
with hybrid technology are available only up to lower mid-size performance. The
main markets are Japan and the USA, but the European market is increasing [9].
There are new hybrid commercial vehicles in specific sectors of road trans-
portation, e.g., in mining technology. However, the development is going in the
direction of general using hybrid technology in road transport. In hybrid vehicles,
recent performance of the internal combustion engine attaches 250–1,397 kW
(335–1,873 HP), the cylinder volume reaches up to 7–16 l (0.25–0.56 ft3), and the
17.1 Future Trends of Road Vehicle Technology 269
starter
internal
crankshaft-
propulsion coupling combustion
starter
engine
internal
crankshaft-
propulsion coupling coupling combustion
starter
engine
internal
electric
propulsion generator combustion
engine engine
Hybrid cars are particularly advantageous in large cities, where traffic con-
gestion causes an enormous waste of time and energy and where pollution causes
several diseases and environmental damage [11].
Future hybrid motor vehicles will remain more expensive than similar cars with
combustion engines, since all supplementing parts of the propulsion must be
doubled, which measure increases the costs of production and maintenance.
However, future vehicles with hybrid propulsion will be more comfortable and
will need less fuel [12].
The propulsion of an electric motor vehicle consists of the engine, the transmission
system, and the power sensor which converts the accelerator pedal’s position into
the appropriate current and voltage regulator of the engine.
The main characteristics of electric vehicles depend on the battery type.
Any household electric socket can be used to charge the battery, supplying
electric power of 3.7 kW (3.51 BTU s-1) per hour. Charging for one hour can fuel
a trip of approximately 20 km (12.43 mi). Shorter charge times can be achieved by
the use of an industrial current connection which is often used for forklifts in
stores. It takes 100 times longer to recharge a battery than to refuel a combustion
engine to travel the same distance [13].
The design of the newest lithium-ion batteries is compact, the construction is of
a relatively light weight, and the durability covers approximately 10 years or
600,000 charging-discharging cycles. Some models are surrounded by a cooling
gel and achieve 25–50% higher energy density than conventional nickel-metal
hydrid batteries; see Fig. 17.5.
Lead–acid batteries are most common in road vehicles. In modern electric cars,
nickel and lithium-ion technology are replacing lead–acid batteries.
The advantages of the lithium-ion technology are the high thermal stability and
the high capacity. However, some elements have to be improved, such as the
cooling unit, the battery management system, and the high voltage connection.
Batteries with organic lithium electrolytic solutions are combustible and can
lead to severe injuries in case of accidents. Therefore, it is important to design
future batteries that do not burn. For this reason, non-flammable lithium-polymer
technology, including an electrolyte solution made of polydimethylsiloxane and
electrodes designed with nanotubes will gain importance in the future [14].
Fiber-reinforced synthetic materials and metal containers with a strengthened
wall are used to protect against mechanical shocks. The electronic control unit
avoids overcharging the lithium-ion battery, saves it from damage when starting at
high temperatures, and records events which are important for the maintenance of
the system [15].
In contrast to the internal combustion engine, the electric propulsion must
distinguish between short and long time engine power. The short time power is
limited by the maximum power of the supply. The maximum power is a half hour
17.1 Future Trends of Road Vehicle Technology 271
100 4
3
1
2
10
1
1 10 100 1,000 10,000
density of energy [Wh*kg-1 ]
1. lead-acid 4. lithium-ion
2. nickel-cadmium 5. internal combustion engine
3. nickel-metal hybrid 6. gas turbine
900.0
800.0
number of vehicles*10 6
700.0
vehicles with combustion engine
600.0
micro and mild hybrid
500.0
full hybrid
400.0
electric cars
300.0
200.0
100.0
0.0
2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
year
Optimistic predictions say that by 2030 or 2050 no more new motor vehicles will
be sold without electric or hybrid drive but in fact, the time when mass trans-
portation with new technology can achieve a leading role at a reasonable price,
seems to be very uncertain.
To supply electric cars a net of intelligent recharging stations will be necessary.
The condition and the efficiency of the battery must be measured by the recharging
stations. Future charging stations will be able to control the battery functions [18].
Pay stations at public parking places or at company parking lots will recharge
most electric cars. The data will be passed on to a computer for accounting by the
17.1 Future Trends of Road Vehicle Technology 273
switch
Fig. 17.7 Connection of the electric grid to electric cars for charging and storing energy
energy supplier. The vehicle will be able to communicate with the on-board power
supply system or its account data management at the recharging station.
Renewable energy has the disadvantage of variable production which often does
not meet the demands of industry or consumers. The power output of wind and
solar power plants entirely depends on the weather; but energy consumption
depends on the time of day. It would be ideal if electric cars could store and use
renewable electric energy.
The additional power of wind or solar plants could be stored in the batteries of
electric cars. This would improve the alternative network management and sim-
plify the regulation of the net’s stability; see Fig. 17.7 [19].
The timing of charging electric cars is very beneficial for the electric supply
because motor vehicles should be recharged when the current is cheaper, i.e., at night.
Workers would drive to work in the morning and while parked at their place of
employment the extra current from the car could be fed back into the net at a top price.
274 17 Future Transportation Systems
solution of technical
100 problems
costs [%] 80 application of innovative materials and
new production technology
60
40
introduction into market
20
0
2010 2015 2020 2025
prototype prototype first small quantity quantity
production production
years
The electric car as a storage system is still a research project for the regulation
and storage of electricity in a future grid, but it seems to be very meaningful.
Fuel cells function similar to batteries and produce electricity from chemical
reactions of H2 and O2 by combustion without flame at lower temperatures in the
presence of catalysts. They replace large, heavy batteries, and run with a high
efficiency and low emissions. Recent models are usable from a few Watts to a few
Megawatts.
However, the price of fuel cell technology must be greatly decreased before it
become popular; see Fig. 17.8 [20].
In solid oxide fuel cells, the temperature of operation decreases from 800C to
650C, i.e., from 1,472F to 1,202F. The technology uses a high power density
and is of optimal durability. The oxide layer could be sprayed by an automated
process which could be a path towards cost-effective mass production [21].
Solid Acid Fuel Cells operate at low temperatures, have a performance of
250 W (0.34 HP), and use diesel fuel for the hydrolysis. One predicts they are the
best solution for the future [22].
Currently, there is no enough data on the life span and durability of fuel cells in
regular use. The most important application of fuel cells is the production of
energy in spacecraft and in submarines. This is still a very small field. Profitable
mass production seems to only be realistic in the future.
Hydrogen can be burned like gasoline inside the engine or used in fuel cells to
generate power. A hydrogen fuel cell produces current made from hydrogen and
17.1 Future Trends of Road Vehicle Technology 275
oxygen. Experimental electric cars with hydrogen fuel cells and electric motors
produce 100 kW (94.79 BTU s-1) and have a range of 450 km (280 mi). The
current is stored in a lithium-ion battery which powers an electric motor. A tank
holds about 4 kg (8.31 lb) of compressed hydrogen [23].
Hydrogen has two main benefits. Its mass-specific energy content is three times
higher than gasoline and it produces water in the exhaust of the combustion.
However, production of pure hydrogen from water through hydrolysis requires
high energy. Hydrogen produced from natural gas by hydrocracking is not an
environmentally friendly production process.
Future generations of alternative energy will also improve hydrogen produc-
tion, primarily through the use of wind power; see Table 17.3 [24].
The range of hydrogen-powered cars is further and the refueling time is shorter
than of average battery powered electric cars. However, the storage of hydrogen is
difficult and dangerous because its tiny molecules escape from almost every
pressure vessel. These problems do not exist with liquid hydrogen. Hydrogen
becomes liquid at minus 253C (-487F). This very low temperature is produced
by cryogenization, which is an expensive energy-consuming process.
Hydrogen fuel cell technology needs a few more years of development until the
cells are cheaper and convenient enough to be mass marketed. The attainable energy
densities of electricity stored in batteries or of hydrogen stored in fuel cells cost about
0.01 kWh Euros-1, i.e., 0.009 BTU s-1 Euros-1. In comparison, the gasoline
energy density costs approximately 6 kWh Euros-1, i.e., 5.69 BTU s-1 Euros-1
[25], i.e., it is more economic.
According to experiences, it is not possible to replace fossil fuels such as
gasoline, diesel, kerosene, or heavy marine diesel oil in the transportation of
passengers and goods by known alternatives within the next decades. Alternative
energy carriers and fuels will come slowly and replace fossil fuels only in a small
sector of the market.
276 17 Future Transportation Systems
CNG costs much less than gasoline or diesel fuel. The reason is not only its
optimal physical and chemical properties, but also the current taxation system.
Vehicles powered with compressed or liquefied natural gas emit 25% less CO2
and 75% less pollutants than those using gasoline. Instead of natural gas, cars can
use biomethane produced in a renewable way. Using Liquefied Petroleum Gas is
usually less sustainable for the environment because it emits more pollutants in the
exhaust gas [26].
Retrofitting costs €2,000–3,000, i.e., US $2,860–4,290. Changing from gasoline
to CNG to fuel a car is cheaper only after driving 50,000–70,000 km (31,075–
43,505 mi) per year. New CNG vehicles have a more reasonable price. In the
future, the advantage of natural gas will certainly appear sooner for drivers
because of the increasing price of gasoline and diesel fuels.
The reformation of methanol (CH3OH) seems to be the key to fuel cell technology.
Methanol is produced from natural gas with approximately 65% efficiency. It is a
liquid similar to gasoline and diesel fuel, and has a high energy density. Methanol
is available in the existing infrastructure.
The reaction takes place with air and water at temperatures of 800–900C
(1,472–1,652F). Natural gas is partially oxidized and converted in two catalytic
steps with H2O to H2, CO2, and CO. Carbonization and inhibition of the catalyst
must be avoided. The remaining residue of CO must be separated by gas selection,
because it inhibits the electrodes of the fuel cell [27].
The reformation of methanol is substantially more difficult than the conversion
of methane to hydrogen. The process could be substantially improved in the future
if catalytic technology were developed.
Civil air transportation will need approximately 24,000 new airplanes in the next
20 years. Freight transport is expected to increase 5.2%. About 3,440 new air-
planes and approximately 850 rebuilt airplane will be needed for air freight ser-
vice. The total cost of all the new airplanes will be approximately €145 thousand
million, i.e., US $210 thousand million in 20 years [28].
By 2030, passenger transportation will require approximately 1,700 Very Large
Aircraft each carrying more than 400 passengers. The investments will cost €399
thousand million, i.e., US $571 thousand million in 20 years.
There is a projected need for about 6,250 large airplanes carrying 250–400
passengers, i.e., 42% of the market and for about 17,000 small single aisle air-
planes, i.e., 39% of the market in the same time interval.
17.2 Future Trends in Aviation Technology 277
Reducing drag ensures the most benefits in fuel consumption and lowers operating
costs. The improvement in the wing geometry of older models, compared to new
types of airplanes could decrease aerodynamic resistance by approximately 12%.
Variable wing profile in the rear area of the wing could also save 8–10% and will
be advantageous especially when applying extended flaps. Improving aerody-
namics is expected to save 3–4% of fuel while cruising despite the larger size and
weight. The wing box would remain unchanged [29].
Winglets at the wing tip will be widely introduced and will already increase the
aerodynamic efficiency of airplanes in the near future.
Noticeable weight savings are expected through the use of better materials and
improved designs. The best examples are aluminum–lithium alloys, which are 5%
stronger and 10% lighter than conventional aluminum alloys [30].
In the future, Carbon Fiber Composite (CFC) will be extensively used in load-
bearing structures such as the wings and the fuselage. Reducing weight with CFC
will reduce fuel consumption by up to 25%. The rudder assembly was the first
primary structure built with CFC material.
Today, CFC has already proven itself in secondary structures such as in spoilers
and in landing gear. In the future both the quantity and the quality of new com-
posite materials will increase. However, they will only become advantageous if
their costs are reasonable, the inspection and the maintenance requirements do not
increase, and the risks of using them are safely controlled.
Several airplane manufacturers are attempting to introduce new fuels for airplanes.
Not only environmental and climate protection, but also the price of conventional
278 17 Future Transportation Systems
fuel demands continuous development. New fuels based on sugarcane have been
tested in several laboratories of the U.S. Air Force and the Royal Air Force.
Manufacturers and legislators have predicted that biogenic fuels in aviation can be
widely marketed [31].
The most spectacular step in the history of commercial flight was the transition
from the piston engine to the gas turbine. There will not be similar revolutionary
innovations in foreseeable future but a series of small improvements [32].
Greater bypass and higher compression ratios will further lower the fuel con-
sumption. Enlargement will be limited by the increasing cross-section area and the
higher aerodynamic resistance of larger jet engines with more and more increased
bypass ratios. Currently, the upper limit seems to be a bypass relationship of
approximately 10:1.
Future jet engines will work with even higher compressor pressure ratios which
are over 50:1 but the turbine inlet temperature does not allow a ratio higher than
about 45:1. If the ratio went above this then the maintenance costs would become
too high. Emissions and fuel consumption can be decreased by 10% with improved
combustion chambers. However, the technology will be developed slowly and
research will become increasingly expensive.
New propfan engines will increasingly combine the advantages of turboprops
and turbofans. The modified propeller drive of the fan will reach an efficiency of
80%. However, future improvements require better noise insulation of the fuse-
lage. Passive methods such as optimal insulation walls and active sound reduction
technologies, such as the use of fast regulated loudspeakers with different fre-
quencies and amplitudes will gain a decisive role also in civil aviation. Currently,
this technology is widely used in military transportation. Improvements in the
construction of the transmission and in the design of the propeller blades can
further decrease noise emissions and increase durability.
The use of advanced fuel cell technology could make taxiing near terminals more
environmentally friendly. New type of electric motor could be built into the nose
wheel of airplanes. Taxiing a mid-range single aisle airplane requires about 50 kW
(67.1 HP) of energy with high torque [33].
The starting inertia of an airplane can be optimally overcome through the use of
an electric engine in the first seconds of taxiing because they have relatively high
performance with low inertia. A fuel cell can be installed in the fuselage near the
wheel. The way to practical introduction of this technology is the development of
light weight fuel cells with high efficiency because a large weight of current fuel
cells could result in increased fuel consumption of the airplane in flight.
17.2 Future Trends in Aviation Technology 279
Airplanes which are just being tested in flight today will be in regular commercial
service in the next 30–40 years. During their long service life, their interiors,
fuselages, and cabins may be frequently modernized and their jet engines may be
modified many times. Older airplanes can be retrofitted to the most modern
standard. This is the way that airliners are going if they are rebuilt to being freight
transporters after a long service time interval.
Airports and airspaces are currently becoming more and more overcrowded. Since
air traffic will double within the next 15 years, the available airport capacities
cannot handle these increases. Super large airplanes with 600–1,000 passengers
could be a way out [36].
Future airports will manage large numbers of passengers, especially, if several
large airplanes arrive or takeoff at short intervals. Airport services such as fire
fighting, de-icing, and ground handling equipment will need to be increased.
280 17 Future Transportation Systems
Future runways, taxi ways and aprons must be able to carry over 500 t (492 lnt,
i.e., 1.102 9 106 lb), compared to 350 t (344 lnt, i.e., 0.771 9 106 lb) today. They
will have to manage wing span widths of 85 m (278.7 ft), instead of 60–70 m
(196.7–229.5 ft) currently, to keep parked airplanes from touching each other.
Will the fight for market share produce still bigger and faster airplanes? Air-
planes will probably not be bigger or faster than the most recent large airplanes in
the foreseeable future. In large airplanes, the design of the space for the passen-
ger’s compartment represents the greatest challenge, because more passengers
must be accommodated in the cabin. Besides the fuselage, the wings and all other
parts require new designs. The development is cost intensive and requires time.
Reducing air resistance permits flights at higher speeds and improvements in the
glide ratio. In the last few decades, the average Mach number of civil aviation has
increased from M 0.78 to M 0.82.
Adding winglets and improving the wing profile provides only a limited
improvement. Apart from this technology, improving laminar flow will be a really
revolutionary step. Currently, the boundary layer leads to friction resistance which
is half of the complete resistance of a commercial aircraft while cruising. The
Reynolds number determines whether the bordering layer will be laminar or tur-
bulent. In flight there is a Reynolds number between 20 9 106 and 70 9 106, so
the boundary layer is always turbulent. With artificial laminar flow, the friction
resistance could be reduced by 90%. No other measure yields such large benefits.
This will be the central topic in future aeronautical research [37].
Improving the wing construction will produce laminar boundary layers. In
practice, only a part of the wing will have a laminar flow, but with an artificial
vacuum, 75% of the wing area will be attainable. At this way, friction resistance
will be lowered to 30% and the glide ratio will be correspondingly improved. The
profits will be considerable. 10% fuel will be saved on short range flights. Long
range flights will save up to 20%. However, tests are still in progress.
Wing load is the loaded weight of the aircraft divided by the area of the wing. The
faster an aircraft is flying, the more lift is producing by each unit area of the wing,
so a smaller wing can carry the same weight in level flight with a higher wing load.
Correspondingly, the takeoff and landing speeds will be higher. High wing load
also decreases maneuverability [38].
Table 17.4 shows the parameters of airplanes with different wing aspect ratios.
The airplane of tomorrow can be constructed like an oversized glider with
efficient aerodynamics, but the enormous wings will have to be reinforced through
17.2 Future Trends in Aviation Technology 281
strutting, to safely connect with the fuselage. If possible, the wings must be
retractable to enhance the safety of taxiing; see Fig. 17.9.
Important aerodynamic improvements require further developments for
attaching the fuselage to the wing. The tail unit and the horizontal stabilizers could
be constructed with high vertical size. The optimally insulated engines with low
noise emissions can be placed near the fuselage which can also stabilize the
operation of the airplane [39].
The aspect ratio of the wing depends on the price of fuel. If the fuel is cheap, the
price of the airplane is decisive and a very small wing aspect ratio is optimal. If the
fuel is more expensive, small fuel savings are also profitable. In this case, man-
ufacturers will build a larger wing aspect ratio which will be bigger than the
optimal size.
Blended wing body airplanes could be introduced after 2050. Figure 17.10 shows a
model of a blended wing airplane.
The cost of fuel will bring about a radical change in transportation. It is
absolutely not certain whether a blended wing airplane will be developed, even in
the distant future. An earlier introduction could be possible as an air freighter.
However, from an operator’s point of view, it is cheaper and simpler to convert a
passenger airplane to being a freight carrier, after 10–15 years of service [40].
Smaller experimental aircraft already use an electric powered propeller. The wing
span is 13–14 m (42.6–45.9 ft), the empty weight with the battery is 250–300 kg
(551–661 lb), and the motor produces 40 kW (54 HP) [41].
The battery supplies the engine with 66.6 V for a power of 30 Ah. The lithium-
ion-polymer battery provides 54 cells. The weight is 12 kg (26.4 lb) per cell, which
282 17 Future Transportation Systems
supplies power to the engine for 1.5–2.0 h. The price is about €100,000, i.e., US
$143,000.
The development of an all-electric airplane with fuel cell technology has high
potential for saving fuel while cruising in the very far future.
The fuel cell powered experimental airplanes has two additional outer tanks under
the wings for the hydrogen powered fuel Antares DLR-H2 cell and for the com-
pressed gas. It is an unmanned airplane with hydrogen fuel cells which produces
25 kW (34 HP), i.e., 23.7 BTU s-1 [42].
The small airplane is able to fly 750 km (466 mi) in 5 h at a speed of
170 km h-1 (91.8 nmi h-1); see Fig. 17.11.
In the future, fuel cells may become more important in specific sectors of
aviation, depending on their efficiency.
Solar airplanes are equipped with solar cells. They are still able to fly around the
world. The fuselage is 20–22 m (65.6–72.1 ft) long; the wing is 63.0–63.4 m
17.2 Future Trends in Aviation Technology 283
(196.7–207.9 ft) wide on the leading edge. The airplane is built of CFC substances
and honeycomb sandwich construction modules for the fuselage to achieve the
required strength, rigidity and lightness. The wings have a lot of risks to strengthen
the construction, e.g., 120 carbon fiber ribs at 0.5 m (1.64 ft, i.e., 0.55 yd) intervals
to create the airfoil shape, and support the skin of the upper and lower wing.
Therfore, the proportions of the experimental airplane and the length of the wing
are very similar to a single-aisle airplane [43].
In fact, solar cells cannot provide the entire energy for future airplanes, but they
can contribute to the utilization of solar energy as auxiliary power.
284 17 Future Transportation Systems
propeller
H2 reservoir
fuel cell
All forecasts assume growth in air traffic. Particularly, the leading airports will
have to cope with more air traffic in a few years. For solving the task, several ways
are imaginable to increase airport capacity [44].
The first way is intensive international cooperation which will be generally
necessary to solve the problems. In this process, airfreight may be shifted from
civilian airports to former military airports. Parallel to it, smaller secondary air-
ports could be strengthened more for intercontinental aviation with modern nav-
igation and communication equipment.
The demand for very short distance air travel could decrease in the future
depending on fuel prices, infrastructure, and economy. This problem should be
solved by development of special low cost airplanes with open, contra rotating
turbofan engines with high efficiency.
100
60
40
20
0
emulsion emulsion and exhaust gas water injection SRC
with 20% H2O late injection recirculation 10% with 50% H2O
New developments in all types of ships, such as bulk carriers, tankers, container
ships, cruise ships or freighters, etc., will increase their safety, economy, power,
durability, and flexibility. Besides the development with fossil fuels in the con-
ventional way, continuous development will be possible if new types of fuels and
renewable energy sources such as wind and sun energy will be used with higher
efficiency. Complementary new propulsion technology will become more
important.
Decreasing exhaust gas emissions with internal and external measures will be
more important in the future. The inherent advantage of the slow speed marine
diesel engine is its high efficiency. The amount of HC and CO in the engine’s
output is usually very small. However, the concentration of particles has to be
decreased with a special exhaust gas after treatment system behind the engine,
particularly when heavy fuel with high sulfur concentration is burnt. Marine
exhaust gas after treatment technology is important for decreasing SOx, NOx, and
particle emission concentrations.
There are increasingly strict requirements for decreasing emissions from the
engine and the exhaust gas after treatment device in marine technology. NOx
emission values must be lowered to MARPOL 73/78 Convention, Annex VI limits
between 2.0 and 3.5 g kWh-1, i.e., 21.0 9 10-6 and 36.8 9 10-6 oz BTU-1 for
ships launched after January 1st, 2011 [45]. A further stage is the 80% reduction of
emissions with Tier 3 limits applicable from 2015/2016 [46].
NOx can be reduced by approximately 30–40% by injecting a direct water
emulsion and through further measures, e.g., late injection; see Fig. 17.12.
286 17 Future Transportation Systems
30
consumption [%]
change of fuel
20
10
7% for MDO
0
emulsion emulsion and exhaust gas water injection SRC
with 20% H2O late injection recirculation 10% with 50% H2O
Fig. 17.13 Changes in fuel consumption with fuel preparation and exhaust gas after treatment
The highest rates of reductions, of up to 95%, can be reached by the use of SCR
technology. In a two-stroke marine diesel engine the SCR reactor nury advanta-
geously be put in front of the exhaust gas turbocharger because of the optimal
temperatures in the area [47].
Furthermore, there are several other methods for decreasing emissions. How-
ever, these methods usually have individual side effects which are disadvanta-
geous. Humid air engines require less water, but need large humidification towers.
Emulsified fuels require large quantities of water from freshwater production
plants. Fuel-Water Emulsions (FWE) have lower heating values and higher vis-
cosities than pure HFO. Emulsified fuels require an increased injection pump
capacity and a bigger final heater [48].
FWE requires increased preheating temperature and higher feeder pump pres-
sure to avoid water evaporation. Parallel to decreasing the exhaust gas emissions
all these methods cause higher fuel consumption; see Fig. 17.13 [49].
Further aims for improvement of exhaust gas quality in marine technology are:
• Reduction of NOx concentrations in the exhaust gas by 40–50% at sea and up to
80% in coastal waters, i.e., 50–200 nmi or 92.6–370.4 km off shore [50];
• Reconstruction of existing engine technology on ships built before 2000 to be in
compliance with the current NOx emission limits; and [51]
• Lowering the operating costs and space requirements of exhaust gas after
treatment systems for broad ranged applications [52].
The average sulfur content of marine diesel fuel is 3.0–4.0% by weight. Operation
with a standard HFO with sulfur content higher than 1% may lead to clogging the
catalyst because the exhaust gas temperature of marine diesel engines is too low to
avoid deposits under most operating conditions. The best results can be reached
through the combined use of low sulfur fuel and SCR technology [53].
17.3 Future Trends in Ship Technology 287
Currently, single filter system is state of the art in ship technology. In the long
term, particle filters will be integrated into catalyst system in an effort to
288 17 Future Transportation Systems
Fig. 17.14 Common air intake and exhaust gas after treatment system
effectively reduce common NO, NO2, and particle emissions. Systems must be
suitable for both retrofitting and for new engines. The required separation rate is
approximately 70% [56].
Figure 17.14 shows the elements of the common air intake and exhaust gas
after treatment system.
SCR and connected filter technology offers the largest future potential for the
improvement of the exhaust gas treatment on ships. This procedure can be combined
with exhaust gas recirculating and the catalyst can be integrated into the muffler. SCR
technology in ships can only be used when ships combust low sulfur bunker fuels.
Filter on ships have to operate under raw conditions. The pressure difference in
the filter between the entrance and the exhaust side can be measured with pressure
sensors. A blocked filter leads to an increased pressure difference between the
sensors. The filter must be regenerated before high counter pressure can seriously
increase fuel consumption or stop the engine. In ships, the filter is heated by a
burner to 600C (1,112F). Starting at 550C (1,022F), the deposited soot burns
away and leaves the filter as CO2. If the filter is frequently clogged with ash, the
regeneration requires longer time interval or higher temperatures. In critical cases,
it cannot be regenerated anymore [57].
tow kite
steering
system
launching and landing
system
steering gondola
pull rope
winder
power
with a flashpoint of over 60C (140F) may be used on ships. That is the reason
why kerosene is also prohibited. So far exceptions to this rule are ships in inland
navigation, e.g., ferries and seagoing LNG tankers which are allowed to use the
burn-off gas in their internal combustion engines [58].
Tow kites generate 2–3 times the energy per square meter compared to normal
sails depending on their shape which is comparable to that of a paraglide [59]. The
kite system consists of a simple main stunt kite for propulsion, made of a strong
and weather-resistant textile and is able to fly at altitudes between 100 and 300 m
(328 and 984 ft), where steady winds are predominant; see Fig. 17.15.
Tow kites decrease the operating costs of a ship between 10 and 34%,
depending on the wind. With optimal winds, fuel consumption can be temporarily
reduced by up to 50%.
In the future, nearly all bulk carriers, cruise ships, and trawlers may use tow
kites which can be retrofitted. This means that approximately 10,000 ships could
be retrofitted worldwide with a tow kite system.
Currently a new experimental ship with a four man crew, such as a catamaran with
a particularly low hydraulic resistance coefficient and light weight is already able
290 17 Future Transportation Systems
solar cells
to successfully navigate around the world using photovoltaic cells [60]. The ship is
23 m (75.4 ft) long, 6.1 m (20 ft) high, and reaches a weight of 85 t (187 225 lbs).
It is built from CFC and other light weight plastics, and can run with battery power
for 66 h, and costs about €1.0 million, i.e., US $1.43 million.
Large vessels such as bulk carriers are also experimenting with photovoltaic
cell technology. By means of some examples, the solar panels are installed on the
deck of a bulk carrier; see Fig. 17.16.
Initial tests show that solar cells generate 1.4% more energy at sea than on land
because of higher radiation intensity. However, photovoltaic solar power provides
approximately 1–3% of the on-board electricity of large tankers, when all the free
places are covered by solar panels. From experience, current panels survive severe
conditions in heavy storms with constant rain, lightning, and pounding from waves
up to 4 m (13.1 ft) high.
The far future aim is to use solar and wind power to reduce fuel consumption
and CO2 emissions by up to 50%. The newest photovoltaic cells have efficiency of
more than 17.5%, but their durability and costs for the marine technique must be
still improved. The same requirements are valid for other alternative energy
sources. Despite all improvements, the current level of alternative technology can
only save a small part of the energy that a ship needs [61].
Fuel cell propulsion has been developed for submarines of first, because they
operate without ambient air for a long time. Fuel cell technology in civil ships
would provide a lot of advantages such as better environmental protection, lower
costs, and higher durability than conventional propulsion systems. Civil ships
usually use small and in the most cases transportable 160 kW (215 HP) hydrogen
fuel cells in 20 ft containers consisted of four separate modules by a performance
of 4 9 40 kW (4 9 54 HP).
17.3 Future Trends in Ship Technology 291
Electric drive and fuel cells can only be realistically introduced in the market when
their price is reasonable. In the future, reduction of fuel consumption and exhaust
gas emissions will become increasingly important. The requirements will impact
both, the direct costs, i.e., the production as well as the indirect costs, i.e., the
operation costs.
However, customers will certainly not be willing to pay the higher costs, if the
only benefit is the protection of the environment. More safety, higher intelligence,
more comfort, better durability and lower specific costs are also decisively important.
The internal combustion engine will not be replaced in the near future but rather
will be continuously developed. In highly intelligent cars, navigation can effec-
tively contribute to lower fuel consumption and emissions. Cars and trucks,
driving in convoys could additionally save fuel and space on the highways and
main traffic roads. The combined combustion of natural gas and petrol as a fuel
will be further improved in the near future.
Future pollution can be reduced by about 30% by premixing the fresh air and
the fuel, recirculating the exhaust gas, using a SCR catalyst, and a particle filter
system. Passive filter systems consist of a single filter and a catalyst module, which
filter up to 70% of the particles. In these simple filter systems, neither an electronic
nor an engine control system needs to be adapted. In opposite to them, active filter
292 17 Future Transportation Systems
systems are common with the catalyst, are connected to the ECU, and can be
regenerated by heat when required. They reach a higher rate of filtering than
passive filter systems, but their costs are higher.
Hybrid vehicles with both an electric motor and an internal combustion engine
will become more accepted in certain regions, initially in megacities. Electric
motors can be optimally used when large forces are needed, when accelerating,
driving up hill, and in ‘‘stop and go’’ traveling. Nowadays not technology or
human behavior, but traffic jams are usually the main reason for higher fuel
consumption and higher exhaust gas emissions.
In the future more plug-in hybrid vehicles will be recharged from the net,
extending their range. The cost of hybrid systems will remain very high, since a
combined system must contain many duplicate elements in comparison to single
systems. Due to new promising developments in low and high temperature
membrane technology, many manufacturers consider the fuel cell as an alternative
to the combustion engine. May be, future designs could sooner prefer fuel cells.
However, the single cell is only one component of the combined engine and
storage system in the vehicle. Realistically, it will be a long time before it is on the
market.
Self Diagnosis system will ensure that internal combustion engines operate with
optimal combustion and beyond it, at the best range of load level and number of
revolutions over longer distances. The specific fuel consumption and the pollutant
emissions of future cars will be lower, in comparison with recent types, particu-
larly in urban traffic. The energy of future electric vehicles will be stored in new
types of lithium-ion batteries.
The airplanes of the future will presumably look just like those of today. However,
finances, not the engineering, will more and more determine future designs. The
cost of the fuel, operation, inspection, and maintenance, as well as environmental
friendliness will powerfully influence the economy of an airliner.
Biogenic and alternative fuels or other renewable energy sources will become
more important to protect the environment and the climate. Other aspects will also
become more important, such as the use of light weight materials, the introduction
of laminar flow over the wings, the integration of airframe, and nacelle and new
engine technologies.
Airspace near airports is overcrowded everywhere, so aviation must develop
higher safety standards. The growth of aviation requires new innovations, such as
• The Single Sky initiative in Europe, flights on individually optimized tracks and
profiles, independently from the established route structures;
• The complete digitalization and automatic communication between airplane to
airplane, not only between pilot and flight officer;
17.4 Summary and Recommendations: Future Environment Friendly Transportation 293
The slow speed two-stroke marine diesel engine will certainly consolidate its
leading position with its optimal thermal effectiveness, resistance to wear, and high
durability. It converts more than 50% of the chemical and thermal energy to
mechanical work because of its high thermal efficiency. Theoretically more than
60% thermal efficiency is possible. However, higher heat recovery is not possible
currently because the exhaust gas heat is used to produce steam, hot water and
fresh water, and to warm the air in the intake which lowers the real thermal
efficiency of engine.
In the future, the power of the engine will assumebly increase. Considerable
potential is still available in the application of new materials in the combustion
chamber and in the turbocharger. This development also presupposes an improve-
ment in environmental compatibility and in climate balance of new materials.
Currently, the highest concentrations of pollutants exist in the exhaust gas of
HFO fuel. However, the change between current HFO to higher fuel qualities,
especially to diesel oil, may show incompatibility in the following way in the future:
294 17 Future Transportation Systems
• Low sulfur diesel fuel may not lubricate engines as required; therefore,
mechanical parts may need extra lubrication; and
• The change from hot HFO to cold diesel fuel must be done smoothly to avoid
the injection pump piston seizing up.
The use of an SCR catalyst is the primary method for decreasing NOx emis-
sions. This can be implemented in up to 90–95% of all ships. Advantageously,
SCR is an additional technology and does not influence fuel consumption.
The secondary method is adding water to fuel to produce a fuel emulsion and
humidifying the air for combustion which can lower emissions by 10–15%.
However, these measures can cause corrosion in the engine and in the exhaust gas
after treatment system, and increase fuel consumption. On-board monitoring
equipment can discover deteriorations caused by humidifying.
In the future, emission trading will more and more emphasize decreasing
technologies of fuel consumption and exhaust gas emissions also on ships. For the
precise analysis of quality parameter the implementation of a monitoring system in
the combustion and in the exhaust gas after treatment system may become more
widespread.
Strengthened use of wind and solar energy and improving fuel management are
a realistic way of increasing the efficiency of marine engines. Although new
renewable energy sources will be quickly developed, there will be no alternatives
to internal combustion engines using navy fuel for the next 30–40 years. Broad
range applications of technologies with synthetic and biogenic fuels in shipping
are expected in the far future.
Ships on inland water ways are becoming a more important part of sustainable
transportation. In the course of this process, inland and coast navigation produce
pollution which has an effect on residents in especially sensitive regions such sea
coasts and harbor areas. Expected that in this sector, applications of biogenic and
synthetic fuels will be more quickly introduced than in offshore zones.
References
8. Ford study shows Rankine waste heat recovery system on a light-duty vehicles could almost
met fuel vehicle accessory load on highway cycle. http://www.greencarcongress.com/
waste_heat_recovery/
9. Alles ist möglich. Hybridtechnik. Toyota Deutschland. Spezial Edition. Herbst 2007, pp 10–
11. http://www.toyota.de
10. Hybrid commercial vehicle, HCV. http://www.eucar.be/projects-and-working-groups/
HCV.pdf
11. Hybrid-Technik. Automotor und Sport. No. 03/2008, pp 46. http://www.auto-motor-und-
sport.de
12. Mild hybrid. http://en.wikipedia.org/wiki/Mild_hybrid
13. Das Elektroauto E3. EWE, Oldenburg. http://www.ewe.de
14. Lithium-ion polymer battery. http://en.wikipedia.org/wiki/Lithium-ion-polymer-battery
15. Development of the battery, Varta. http://www.varta-automotive.com/index.php?id=89
16. Volvo launches heavy-duty FE truck in Europe. http://www.green.autoblog.com/2011/04/
volvo-launches-heavy-duty-fe-hybrid-truck-in-europe/
17. Heavy duty (really heavy duty) electric truck in use at LA port. http://www.green.autoblog.
com/2008/06/17/heavy-duty-really-heavy-duty-electric-truck-in-use-at-la-port
18. Charging stations multiply but electric cars are few. http://www.online.wsj.com/article/
5810001424052970203405504576599060894172004.html
19. Vehicle2grid. EFZN. Energie-Forschungszentrum Niedersachsen. http://www.
vehilce2grid.de
20. The fuel cell—energy production without emissions. Making zero emissions possible.
Volkswagen fuel cells and electric drives, pp 26–27. Volkswagen Wolfsburg. http://www.
volkswagen.de
21. Solid oxide fuel cell. http://en.wikipedia.org/wiki/Solid_oxide_fuel_cell
22. Superprotonic solid acid fuel cells: a hidden, cheap, easy way to maintain power source.
http://www.greenoptimistic.com/2009/01/12/solid-acid-fuel-cell-superprotonic
23. Hydrogen Fuel Cells. http://www.hydrogenenergy.gov/pdfs/doe_h2_fuelcell_factsheet.pdf
24. Shell International Gas Limited (2006) Cost-effectiveness of transportation fuel options for
reducing Europe’s petroleum dependence. Final report, May 2006. jant@jthijssen.com
25. Questions and answers about hydrogen and fuel cells. http://www.fuelcells.org/info/library/
QuestionsandAnswers062404.pdf
26. Natural Gas. Natural gas and technology. http://www.naturalgas.org/environment/
technology.asp
27. Direct methanol fuel cell. http://en.wikipedia.org/wiki/Direct_methanol_fuel_cell
28. The future of the narrowbody airplane market. http://www.seekingalpha.com/article/272454-
thefuture-of-the-narrowbody-airplane-market
29. Future technology and aircraft types. http://www.adg.standford.edu/aa241/intro/futureac.html
30. Composites and advanced materials. US centennial of flight commission. http://www.
vcentennialofflight.gov/essay/Evolution_of_Technology/composites/Tech40.htm
31. Biofuels for air travel. http://www.biofuelstp.eu/air.html
32. Small Aircraft Propulsion, The future is here. Glenn Research Center. http://www.nasa.gov/
centers/glenn/about/fs01grc.html
33. DLR Airbus A320 ATRA Praxis using fuel cell-powered nose wheel for the first time. http://
www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10204/296_read-931/
34. Realization of an optimized wing camber by using form variable flap structures. http://www.
mendeley.com/research/realization-of-an-optimized-wing-camber-by-using-formvariable-
flap-structures/
35. Variable camber wing. http://en.wikipedia.org/wiki/Variable_camber_wing
36. Aerodynamic principles of large-airplane upsets. http://www.boeing.com/commercial/
aeromagazine/aero_03/textonly/fo01txt.html
37. Supercritical Airfoil. http://www.centennialofflight.gov/essay/Evolution_of_Technology/
supercritical/Tech12.htm
296 17 Future Transportation Systems
The lack of time limits for future development is the main unsolved problem of
strategies. The dependence on ‘‘time’’ is common in all sectors of transportation
but the interpretation of time intervals is different [2].
The construction, production, marketing or inspection, and maintenance phase
of vehicles, airplanes and ships is measured in months or years. The reference
value is based on the subjective sense of time, depending on temporal experiences
of human beings. This scale could lead to false conclusions and uncertainties or
even qualitative mistakes in the interpretation of trends and prognoses.
The most critical situations are expected in the interaction of fuel supply and
engineering technology. The description of possible scenarios with analysis of
future developments in transportation can foresee qualitative changes only in a
limited way. For this reason, only some basic relationships between fuel supply
and engineering technology can be examined.
Saving fuel is the most important measure for the protection of the environment
and the climate. Development will be shaped by saving resources, decelerating
fuel consumption, supporting technical developments, and producing new type of
transport (4 km h-1) • 1784 hydrogen balloon crosses • 1812 steam surface condenser
• 1786 steam car for the English Channel with elimination of water in the
passenger transport boiler
1850 • 1813 stationary gas engine • 1852 airship with steam engine • ca. 1870 screw propeller • 1857–1859 drilling for oil in Romania,
• 1865 two-stroke (26 km, 85.3 ft) • 1877 merchant vessel ‘‘Turbinia’’ Germany and in the USA
atmospheric engine • 1870 balloons used as blockade with steam turbine (103 ft, • 1861 distillation of navy oil
without compression breakers 27 kn) • 1876 distillation of gasoline
(3 HP) • 1890 airplane with steam • ca. 1880 higher steam pressure • 1892 distillation of diesel oil
• 1878 four-stroke engine (50 m, 164 ft) • ca. 1885 multiple expansion
compression engine • 1890 gliding flight engine
• 1887 three-wheeled car • ca. 1890 effective transmission for
• 1897 self ignition engine steering and propulsion
• 1899 first commercial
vehicle
1900 • 1900 delivery open cab • 1903 airplane ‘‘Flyer’’ (12 s, • 1903 high speed liner ‘‘Vandal’’ • 1903 war production
truck 53 m, i.e., 174 ft) • 1913 ‘‘Vandal’’ rebuilt as a • 1909 automobile market increasing
• 1903 mass production of • 1909 crossing the English warship with diesel–electric (GB used 1 million liters of gasoline per
cars Channel transmission year)
• 1934 front wheel drive • 1919 commercial aircraft ‘‘F- • ca. 1920 coal replaced by heavy • 1939 war production
• 1942 mechanical turn off 13‘‘ navy fuel oil • 1945 increasing prices worldwide
indicator with internal • 1930 jet engine • ca. 1940 first ship diesel engine
light • 1937 helicopter ‘‘VS 300’’
• 1939 jet aircraft ‘‘HE-178’’
(continued)
Interaction Between Future Transportation Technology and Future Fuel Supply
Table 18.1 (continued)
18.2
charging ‘‘X15’’ diesel electric propulsion in • ca. 1980 drilling down to 6,000 m
• ca. 1975 supercharger • 1976 fastest reconnaissance ‘‘Queen Elisabeth II’’
• 1980 carbon fiber material airplane of the world ‘‘SR 71’’ • ca. 1990 use of LNG as fuel in
‘‘Kevlar’’ • 1980 Fly by Wire in ‘‘Concord’’ liquid tankers
2000 • Improved aerodynamics • Higher temperatures and • Tendency to larger hull of • Exploitation rates at 50% by water
• Composite substance in pressures in the combustion merchant vessels injection
construction chamber • Double hull • Tertiary recovery methods by hot steam
• Micro controller technology • Higher bypass ratio and thrust • Fast monohull and water injection with tenside mixtures
• On-board diagnosing • Satellite based navigation • Ring propeller in deep soil layers
• DI, HCCI, combined • First whole plastic and CFC • Linear jet • Excessive production of biomass for BTL
combustion system CCS material airplane • Pod propulsion worldwide
• Mass produced hybrid car • Decreasing SFC and exhaust gas • Saving environment and resources
• Experimental electric car emissions
• Solar power
• Sky Sails
299
300 18 Interaction Between Future Transportation Technology and Future Fuel Supply
100
depletion of
80
mineral
oil supply
60
[%]
Fig. 18.1 Relation between oil consumption and CO2 concentration in air
fuels. However, the introduction of new types of fuels into the market will take a
long time. According to current perceptions, the development of biogenic and
synthetic fuels will probably proceed slowly. The technology of the next decades
will permit blending traditional fuels such as diesel and gasoline with synthetic
fuels, biogenic fuels, or compressed natural gas but this single measure will only
moderately improve complex efficiency.
The technical development of all means of transportation will take place over a
number of human generations in comparison to the development of fuel produc-
tion. The combustion of fuels and the existing of combustion end products in the
atmosphere impact the environment and climate for much longer periods of time
than the life cycle of road vehicles, airplanes, and ships. So, the decomposition
time of CO2 takes hundreds of years; see Fig. 18.1.
The time period ‘‘1 year’’ has a different meaning in transportation and in the
resource system. A circulation of 10 years in technical development is adequate
compared to 1,000 years of transportation’s effects on the environment and on
resources. An optimal organized balance between both time levels is the main task
of engineering technology, and environment, climate, and energy protection.
The time intervals in which new technologies penetrate the market, play a decisive
role in development. A new technology must be reliable, safe, and the operating
costs have to be more favorable than existing technologies in road, air, and sea
transportation, otherwise new solutions will not be accepted by consumers.
After the Second World War, futurologists already intensively searched for
scenarios to analyze the future. Even transportation was considered in the context of
quickly changing and developing cultural values to those time. Since this period in
history, petroleum products have been used in 98% of the world’s transportation [3].
18.3 Summary and Recommendations: Scenarios of Future Transportation 301
Peak Oil (PO) time is the time point when the world oil consumption will reach its
highest level at around 97 9 106 barrel per day, i.e., approximately 5 9 109 t per
year. This time point is expected in this century [4]. Saving fuel between 0.1 and
1.0% with intelligent monitoring technology could mean a financial benefit from
€140 to 1,400 thousand million, i.e., US $200–2,000 thousand million.
Future transport will strongly depend on the market penetration of new fuel
types. However, there are only restricted possibilities to substitute new fuel types
for traditional fuels. For this reason, saving fuel will be the most important
measure to take for a long time.
The longer the epoch of using petroleum in transportation, the bigger are the
chances of developing technology, ecology, economy, society, and politics. Saving
fuel is the only way into the future.
References
Table A.1 Base units of the International System of Units (SI) (Système International d’Unités)
Description Name Symbol
Length Meter m
Mass Kilogram kg
Time Second s
Electric current Ampere A
Absolute temperature Kelvin K
Amount of a substance Mole Mol
Light intensity Candela Cd
Flat angle Radian R
Rigid angle Steradian Sr
Table A.2 Supplementary units of the International System of Units (SI) (Système International
d’Unités)
Description Name Definition
Frequency Hertz 1 Hz = s-1
Strength Newton 1 N = 1 kg m s-2 = 105 dyn
Pond 1 p = 9.807 9 10-3 N
Dyn 1 dyn = 10-5 N
Conversions
Poundal 1 pdl = 0.138 N
Pound-force 1 lbf = 4.448 N
Ton-force 1 tonf = 9.964 kN
Mechanical tension Pascal 1 Pa = 1 N m-2
Phys. 1 atm = 1.01325 9 105Pa = 760 Torr = 1.01325
atmosphere bar = 1.03327 at
(continued)
Conversions
Pound per square inch 1 psi = 6,894.757 Pa
Pound-weight per square foot 1 lbf ft-2 = 47.88 Pa
Poundal per square foot 1 pdl ft-2 = 1.488 Pa
Ton-weight per square foot 1 ton ft-2 = 107.3 kPa
Energy Joule 1 J = 1 N m = 1 Ws = 0.2388 cal = 0.102 kp m
= 2.778 9 10-7 kWh
Volt-Ampere second 1V A s = 1 J = 107 erg = 0.101kp m = 0.238846 cal
= 6.241 9 1018 eV
Electron volt 1 eV = 1.60219 9 10-19 J = 1.6335 9 10-20 kp m
= 96.485 kJ mol-1 = 23.061 kcal mol-1
Calorie 1 cal = 4.187 J = 0.427 kp m = 3.97 9 10-3 BTU
Meter kilopond 1 kp m = 9.807 J = 2.342 cal = 6.122 9 1019 eV
Kilowatt hour 1 kW h = 1.341 HP h = 860 kcal = 367,097 kp
m = 3.6 9 106 J = 3,412 BTU
Conversions
Pound-weight foot 1 lbf ft = 0.138 kp m = 1.356 J
British thermal unit 1 BTU = 0.252 kcal = 107.6 kp m = 1 055.56 J
Ton of coal equivalent 1 tce = 2.931 9 1010 J
Ton of oil equivalent 1 toe = 4.187 9 1010 J
Horse- 1 HPhr = 0.7457 kWh = 641.616 kcal = 273 959
power hour (UK, US) kp m = 2.649 9 106 J
Performance Watt 1 W = 1 J s-1 = 0.856 kcal h-1 = 1.36 9 10-3
HP = 0.101 972 kp m s-1
Conversions
Horsepower 1 HP = 550 lbf ft s-1 = 745.670 W
Pound-weight foot per second 1 lbf ft s-1 = 1.356 W
British thermal unit per hour 1 BTU hr-1 = 0.2931 W
Electricity Volt 1 V = 1 W A-1
Temperature Temperature difference 1 K = tC + 273.15 = 5/9 (tF-32) + 273.15
Degree Celsius 1oC = tK- 273.15
tc = 5/9 (tF - 32)
Degree 1°F = 9/5 (tk -273.15) + 32
Fahrenheit
tF = 9/5 tc+ 32
Appendix A: Applied Units and Conversions 305
Table A.3 Additional units of the International System of Units (SI) (Système International
d’Unités)
Description Name Symbol Definition
Time Minute min 1 min = 60 s
Hour h 1 h = 3.6 9 103 s
Day d 1 d = 8.64 9 104 s
Year a 1 a = nrl. 3.155 9 107 s
Mega year Ma 1 Ma = 106 years = 3.155 9 1013 s
Giga year Ga 1 Ga = 109 years = 3.155 9 1016 s
Flat angle Degree ° 1° = (p 180-1) rad
Length Meter m 1 m = 100 centimeter (cm) = 103 millimeter
(mm)
Kilometer km 1 km = 1,000 m = 106mm = 0.621 mi
Conversions
Statute mile mi 1 mi = 1 760 yd = 1.609 km
Nautical mile nmi 1 nmi = 1.852 km
Inch in 1 in = 2.54 cm
Foot ft 1 ft = 12 in = 0.305 m
Yard yd 1 yd = 3 ft = 0.914 m
League lq 1 lq = 3 mi = 4.828 km
Fathom fa 1 fa = 6 feet = 1.829 m
Cable cl 1 cl = 608 feet = 185.31 m
Sea league slq 1 slq = 3 nmi = 5.556 km
Area Square meter m2 1 m2 = 104 square centimeter (cm2) = 106 square
millimeter (mm2)
Square kilometer km2 1 km2 = 100 hectare (ha) = 104 Ar (a) = 106 m2
Conversions
Square inch in2 1 in2 = 6.45 cm2 = 6.45 9 10-4 m2
Square foot ft2 1 ft2 = 144 sq in = 0.093 m2
Square rod r2 1 r2 = 30.25 sq ya = 25.29 m2
Square yard yd2 1 yd2 = 9 sq ft = 0.836 m2
Acre ac 1 ac = 4,840 sq yd = 4 047 m2
Square mile mi2 1 mi2 = 2.589 km2
Volume Liter l 11 = 1 dm3 = 0.264 gal (US) = 0.22 gal (UK)
Cubic meter m3 1 m3 = 103 cubic decimeter (dm3) = 103 liter (1)
= 106 cubic centimeter (cm3) = 106
milliliter (ml)
Conversions
Cubic foot cu ft 1 ft3 = 1,728 in3 = 28.317 dm3
Cubic yard cu yd 1 yd3 = 27 ft3 = 0.765 m3
Cubic inch cu in 1 in3 = 16.387 cm3
Pint (US) pt (US) 1 pt (US) = 0.473 l
Pint (UK) pt (UK) 1 pt (UK) = 0.568 l
Quart (US) qt (US) 1 qt (US) = 2 pints (US) = 0.946 1
Quart (UK) qt (UK) 1 qt (UK) = 2 pints (UK) = 1.137 1
Gallon (US) gal (US) 1 gal (US) = 4 quarts (US) = 3.785 l
Gallon (UK) gal (UK) 1 gal (UK) = 4 quarts (UK) = 4.546 1
Barrel (US) bbl 1 bbl = 42 gal (US) = 158.987 1 = 0.159 m3
Dry barrel (US) dbbl 1 dbbl = 0.1156 m3
Gross register tonnage GRT 1 GRT = 100 ft3 = 2.8317 m3
(continued)
306 Appendix A: Applied Units and Conversions
Conversions
Pound lb 1lb = 16 ounces (oz) = 0.454 kg
Ounce oz 1oz = 28.35 g
Hundredweight (UK) cwt 1cwt = 112 Ib = 50.802 kg
Long ton (UK) ltn 1ltn = 20 cwt = 2,240 Ib = 1.016 metric t =
1,016 kg
Short ton (US) shtn 1 shtn = 2,000 Ib = 0.907 metric t = 907 kg
Slug sl 1 sl = 14.594 kg
Density Kilogram per liter kg dm-3 1 kg dm-3 = 1 t m-3 = 1 g cm-3 = 103 kg m-3
Pound per cubic foot lb ft-3 1 lb ft-3 = 16.018 kg m-3 = 0.016018 kg t-1
Pound per gallon (UK) 1 lb gal -1 (UK) 1 lb gal -1 (UK) = 0.099776 t m-3
Pound per gallon (US) lb gal-1 (US) 1 lb gal-1 (US) = 0.11983 t m-3
Speed Meter per second m s-1 1 m s-1 = 3.6 km h-1 = 2.237 mph
Foot per minute ft min-1 1 ft min-1 = 5.08 9 10-3 m s-1 = 1.83 9 10-2
km h-1 = 1.14 9 10-2 mph
Miles per hour mph 1 mph = 1.609 km h-1 = 0.447 m s-1
Knot kn 1 kn = nautical or sea mile per hour = nmi h-1 =
1.852 km h-1 = 0.514 m s -1
-1
Fuel Liter per 100 km 1 9 100 km 1 l 9 100 km-1 = 282/mpg (UK) = 235/mpg
consumption (US)
Conversions
Miles by gallon (US) mpg (US) 1 mpg (US) = 235.21 l 9 100 km-1
Miles by gallon (UK) mpg (UK) 1 mpg (UK) = 282.48/l 9 100 km-1
Miles by gallon mpg (UK/US) 1 mpg (UK) = 1.2 mpg (US)
(UK/US)
Gram per kilowatt hour g kWh-1 1 g kWh-1 = 10.527 9 10-6 oz BTU-1
Gram per horsepower hour g HPh-1 1 g HPh-1 = 1.360 g kWh-1
Lower heating value of fuel LHV 1 LHV = 10,200 kcal kg-1 = 42 707 kJ kg-1
Specific emissions Gramm per kilometer g km-1 1 g km-1 = 56.8 9 10-3 oz mi-1
Ounce per mile oz mi-1 1 oz mi-1 = 17.543 g km-1
Radiation forcing Milliwatt per square meter mW m-2 1 mW m-2 = 636 lbf ft (s yd2)-1
Dynamic viscosity Poise P 1 P = 0.010 (kp s) m-2 = 0.1 N s m-2
Conversions
Pound per foot and second lb (ft s)-1 1 lb (ft s)-1 = 1.487 N s m-2
Pound-force second per lbf s ft-2 1 lbf s ft-2 = 47.88 N s m-2
square foot
Kinematic Square meter per second m2 s-1 1 m2 s-1 = 106 cSt = 3.6 9 103 m2 h-1
viscosity
Centistoke cSt 1 cSt = 10-6 m2 s -1
= 10-2 St
Conversions
Square foot per second ft2 s-1 1 ft2 s-1 = 0.0929 m2 s-1
Square foot per hour ft2 h-1 1 ft2 h-1 = 2.5806 9 10-5 m2 s-1
Appendix A: Applied Units and Conversions 307
Table A.4 Prefixes of the SI International System of Units ((Système International d’Unités)
Factor Name Symbol
1018 Exa E
1015 Peta P
1012 Tera T
109 Giga G
106 Mega M
103 Kilo K
102 Hecto H
10 Deca Da
10-1 Deci d
10-2 Centi c
10-3 Milli m
10-6 Micro l
10-9 Nano n
10-12 Pico p
10-15 Femto f
10-18 Atto a
H (cont.) L
Holding time, 176 Lack of time limit, 297
Homogenous mixing, 229 Landing and navigation fee, 252
Honeycomb sandwich construction module, Landing cycle, 199
283 Landing gear, 198, 218
Horizontal distance, 215 Last minute change in infrastructure, 293
Hot start, 16, 177, 187 Lead emission, 250
Hot-test, 176 Lead–acid battery, 270
Humidity, 9, 93, 234 Leakage of exhaust gas, 182
Hurricane, 234 Level of emission, 90, 241, 287
Hydrocarbon, 82, 180, 228 Life cycle of ship, 255
Hydrocracking, 275 Light duty vehicle, 10, 38, 62
Hydrodynamic, 109, 117, 260 Light gasoil, 27
Hydrodynamic lubrication, 19 Light plastic, 239
Hydrogen, 26, 274, 290 Lightning strike, 234
Hydrogen to carbon relationship, 19 Ligneous cellulose, 22
Limited airspace, 232
Limiting value, 3, 10, 90
I Linear extrapolation, 245
Ignition quality, 19 Liquid fuel, 13, 26, 185
Improved maneuvering, 278 Liquid hydrogen, 275
Industrial current connection, 270 Liquid paraffin, 19, 21
In-flight data exchange, 224 Liquidity of the shipping company, 255
Infrastructure, 11, 260, 293 Lithium-ion battery, 270, 274
Inhibition of the catalyst, 276 Load of the engine, 9, 65
Initial climb, 217 Local environment, 211
Injection system, 16, 137, 167 Long distance transport, 263, 271
Inland and coast navigation, 294 Long range flight, 26, 280
Inland shipping, 116, 117, 225 Low boiling end point, 15
Inland waterway, 119, 188, 224
Inspection, 191, 192, 205
Insulation blanket, 51 M
Insurance cost, 252 Main engine, 28, 99, 237
Integrated telecommunication system, 209 Main propulsion, 117
Intelligent monitoring technology, 301 Maintenance cost, 47, 127, 192
Intelligent recharging station, 272 Maintenance philosophy, 199
Internal combustion engine, 125, 271, 291 Malfunction, 105, 196, 205
International trade, 28 Maneuvering load, 279
Interpretation of time intervals, 297 Marine diesel engine, 160, 168, 285
Irregular operation of engine, 193, 195 Marine pollution, 221
Market forecast, 255
Mass transportation, vi, 241, 272
J Maximal exhaust gas temperature, 265
Japanese 10?15 mode, 177 Maximum freight load, 47
Jet engine, 149, 200, 259 Maximum takeoff weight, 47, 254
Jet fuel A, 24 Mechanical deterioration, 195
Jet fuel B, 24 Medium speed, 160, 162
Megacities, 271, 292
Member state, 178
K Merchant fleet, 51
Kerosene, 13, 24, 26 Merchant ship, 170, 254
Kevlar, 51 Metal container, 270
Index 315
Metal hydrid, 21 O
Meteorological and navigation information, Obstructions in the vicinity of the airport, 216
220 Oceanographic forecast, 221
Methane, 26, 83, 276 Octane number, 16
Methanol, 22, 26, 276 Oil fired boiler, 51
Methyl tertiary butyl ether, 16 Oil production, 245
Metric unit system, 1 On-board electricity, 290
Micro controller, 5, 8 Open rotor jet engine, 252
Micro particle sensor, 197 Operating cost, 203, 251
Micro, mild and full hybrid vehicle, 269 Operation parameter, 138, 141, 155
Middle distance airplane, 114 Optical sensor, 209, 222
Middle distillate, 27 Optimal bunkering, 260
Mid-size car, 4, 62, 257 Organic lithium electrolytic solution, 270
Mid-size performance, 268 Overhaul interval, 202
Military airplane, 41, 51, 99 Oversized glider, 280, 282
Military airport, 284 Oxygen, 13, 95, 195
Military aviation, 51 Ozone, 227, 228, 241
Misfires, 195, 197
Mixed fuel, 22
Mixture adaptation, 193 P
Mixture tank, 27 Particle, 81, 197, 291
Mock up, 251 Particle filter, 160, 268, 291
Modified propeller drive, 278 Passenger airplane, 257, 281, 293
Molecule, 24, 28, 241 Passenger car, 175–177
Monitoring operation condition, 203 Passenger kilometer, 1, 241
Motor octane number, 16 Passenger mile, 1
Motor vehicle, 18, 173, 272 Passive filter system, 38
Payload, 55, 113
Peak travel time, 41
N Pentane, 24
Narrow body airplane, 45 Performance, 49, 128, 144
National authority in aviation, 178 Permissible engine temperature, 271
Natural gas, 19, 255, 276 Petrol, 13, 15, 27
Navigation, 209, 219, 235 Petroleum refining, 27
Navigational warning, 221 Photovoltaic solar power, 290
Navy gasoil, 27 Pilot-controller communication, 217
New distribution system, 288 Pilot rating, 217
New energy storage system, 259 Piston engine, 278
New propfan engine, 278 Pollutant, 126, 211, 292
New technology, 242, 268, 300 Position of vehicle, 209
Nitrogen dioxide, 1, 91 Positive displacement compressor, 266
Nitrogen monoxide, 1, 91 Power factor, 271
Nitrogen oxide emission, 185, 285 Pre-defined norm, 4
Noise insulation of the fuselage, 278 Present data, 6
Noise level, 242 Pressure regulator, 60
Nomenclature of components, 193 Pressure sensor, 86, 92, 103
Nominal condition, 8, 59 Preventive maintenance, 202, 205
Non-perishable good, 258 Prices of gasoline and diesel oil, 276
Normal aging process, 195 Private jet, 41
Nose landing gear, 198 Professional decommissioning, 239
Nuclear power, 293 Propane, 19
Number of revolution, 97, 160, 265 Propeller, 116, 128, 278
316 Index