LASER IGNITION SYSTEM

(LIS)

Presented by Under the guidance of

K.ROHITH Mrs.P.PRANITHA, M.TECH
154G1A0356 ASSISTANT PROFESSOR
Department of Mechanical Engineering
 INTRODUCTION
• It’s widely accepted that the internal combustion engines will
continue to power our vehicles. Hence ,as the global mobilization
of peoples and goods increases ,advances in combustion and after-
treatment are needed to reduce the environmental impact of the
continued useof ICengine vehicles.
• New engines are becoming increasingly complex, with advanced
combustion mechanism that burn an increasing variety of
fuels to meet future goals on performance, fuel economy and
emissions.
• One of the alternative is the laser ignition system (LIS) being
described here, compared to a conventional sparkplug, a LIS
should be a favourable ignition source in terms of lean burn
characteristics and system flexibility. So , in this seminar we’ll be
discussingthe implementation and impact of LISonIC engines.
 What is LASER?
A laser is a device that emits electromagnetic radiation through a
process of optical amplification based on the stimulated emission
of photons. The term “laser” is an acronym for Light
Amplification by Stimulated Emission of Radiation. Lasers provide
intense and unidirectional beam of light. Laser light is mono
chromatic (one specific wavelength).
 How does laserwork?
Laser are mono chromatic (one specific wavelength). It starts with the
electrons. By sending energy to a system we can achieve what is
known as population inversion. This means that there are more
electrons in the excited states than those in the lower energy states.
As one electron releases energy (a photon), the other electrons
strangely seem to communicate with each other and also begin
releasing photons.
Types of lasers
There are four types of lasers they are :
1.Chemical laser: Lasers that obtain their energy through chemical
reaction. hydrogen fluoride laser(2700-2900nm)
2.Exclimerlaser : It produce ultraviolet light
3.Solid-state laser: neodymium-doped yttrium aluminium garnet
(YAG) Nd:YAG Lasers can produce high powers in the infrared
spectrum at 1064
4.Semiconductor laser: Laser diodes produce wavelengths from 405 nm
to 1550 nm. Low power laser diodes are used in laser pointers, laser
printers, and CD/DVDplayers.
 Background Study of Ignition in ICEngine

What is ignition?
 Ignition is the process of starting radical reactions until a self sustaining
flame has developed. One can distinguish between auto ignition,
induced ignition and photo – ignition , the latter being caused by
photolytic generation ofradicals.
Ignition Types
A. Compression Ignition (CI) or Auto Ignition : At certain values of
temperature and pressure amixture will ignite spontaneously
B. Induced Ignition : A process where a mixture, which would not
ignite by it, is ignited locally by an ignition source
 Conventional Sparking Plug Ignition

 Conventional spark plug ignition has been used for many years.
For ignition of a fuel-air mixture the fuel-air mixture is
compressed and at the right moment a high voltage is applied
to the electrodes of the spark plug.
Current spark ignition system
 WHAT’S THE PROBLEM ?

• Thefollowing arethe drawbacks ofSI:

1. Location of spark plug is not flexible asitrequires shielding
of plug from immense heat and fuel spray
2. It require frequent maintenance to remove carbon deposit.
3. Leaner mixtures cannot be burnedefficiently.
4. Flamepropagation isslow.
5. Higher turbulence levels arerequired
To overcome the above mentioned disadvantages LISis being sought
after
 WHY LASER IGNITION?
 Regulation on NOx emissions are pushing us toward leaner air/fuel
ratios (higher ratio of air to fuel).
 Natural gas is more difficult to ignite than gasoline due to the
strong carbon to hydrogen bondenergy.
 Becauseof the requirement for an increase in ignitionenergy, spark
plug life will decrease for naturalgasengines.
 laser promise less pollution and greater fuel efficiency, but
making small, powerful lasers has, until now, proven hard.
 To ignite combustion , a laser must focus light to
approximately 100 GW/cm^2 with short pulses of more than
10mJeach.
 The laser also produces more stable combustion so you need
to put less fuel into the cylinder, so increase the efficiency.
 Optical wire and laser set up is much smaller than the current
spark plug model, allowing different design opportunities.
 TYPES OF LASER IGNITION
Basically, energetic interactions of a laser with a gas may be classified into one
of the following four schemes asdescribedin
1.Thermal initiation :In thermal initiation of ignition, there is no electrical
breakdown of the gas and a laser beam is used to raise the kinetic energy of
target molecules in translational, rotational, or vibrational forms.
2.Non-resonant breakdown :In non resonant breakdown ignition method,
because typically the light photon energy is invisible or UV range of spectrum,
multiphoton processes are required for molecularionization.
3.Resonant breakdown :The resonant breakdown laser ignition process
involves, first, a non resonant multiphoton dissociation of molecules resulting
to freed atoms, followed by a resonant photo ionization of these atoms.
4.Photochemical mechanisms :In photochemical ignition approach, very little
direct heating takes place and the laser beam brings about molecular
dissociation leading to formation of radicals (i.e., highly reactive chemical
species).
5.Laser Ignition process along time :Laser ignition encompasses the
nanosecond domain of the laser pulse itself to the duration of the entire
combustion lasting several hundreds of milliseconds
NON RESONANT BREAKDOWN
 LASER IGNITION SYTEM FOR AN INTERNAL
COMBUSTION ENGINE

 Laser ignition will replace the spark plug seen incurrent

gasoline engines.
 COMPONENTS OF LASER IGNITION ENGINE
• Power Source
• Combustion Chamber Windows
• Optic FibreWire
• FocusingUnit
• Laser Spark Plug
 HOW LASER IGNITION WORKS?
 The laser ignition system has a laser transmitter with a fibre-optic cable
powered by the car’sbattery.
 It shoots the laser beam to a focusing lens that would consume a much
smaller spacethan current spark plugs.
 The lenses focus the beams into an intense pinpoint of light by passing through an
optical window, and when the fuel is injected into the engine, the laser is fired
and produces enough energy (heat) to ignite the fuel.
IGNITION IN COMUSTION CHAMBER

CONSTRUCTION
 ENGINE EXPERIMENTS:

LASER used is(neodymium-doped yttrium aluminum

garnet)
 ADVANTAGES OF LIS
 More intense spark
 Free choice of the ignition location within the combustion
chamber
 Leaner fuel can burn effectively
 Engines would produce less NOx if they burnt more air and less fuel,
but they would require the plugs to produce higher energy sparks
in order to do so less NOx emission
 No erosion effects as in the case of the spark plugs => lifetime of a
laser ignition
 Systemexpected to be significantly longer than that ofaspark plug
 High load/ignition pressures possible =>increase in efficiency
 Precise ignition timing possible
 DISADVANTAGES
 High system cost
 Concept proven, but no commercial system available in
market yet.
 Laserinduced optical damage
 APPLICATON

 According to the latest international reports, Mazda’s

upcoming rotary sports car could feature laser ignition
technology. This would replace the spark plug ignition system
which is currently applied to every petrol car on the market.
 It’s also a setup a revolution in spark plug which has been not
change around since 1860
 CONCLUSION
 Laser ignition system allows almost free choice of the ignition location
within the combustion chamber, even inside the fuel spray. Significant
reductions in fuel consumption as well as reductions of exhaust gases
show the potential of the laser ignition process. Minimum ignition
energy is mainly determined by the necessary “self-cleaning”
mechanism at the beam entrance window from combustion deposits
and not by engine related parameters. No differences of the laser
ignition processcould be found at differentlaser wavelengths.
 Although the laser will need to fire more than 50 times per second to
produce 3000 RPM, it will require less power than current spark plug.
The lasers can also reflected back from inside the cylinders to relay
information based on fuel type used and the level of ignition,
enabling cars to readjust the quantities of air and fuel for optimum
performance.
THANK YOU