ENGINEERING THERMODYNAMICS B.

TECH II YEAR I SEM R22

UNI-V
Power Cycles : Otto cycle, Diesel cycle, Dual Combustion cycle and Brayton cycle description
and representation on P V and T-S diagram, Thermal Efficiency, Mean Effective Pressures on
Air standard basis Comparison of Cycles. Basic Rankine cycle Performance Evaluation.

TEXT BOOKS:
1. Engineering Thermodynamics, Special Edition. MRCET, McGrahill Publishers.
2. Engineering Thermodynamics / PK Nag /TMH, III Edition
3. Thermodynamics J.P.Holman / McGrawHill

REFERENCE BOOKS:
1. Engineering Thermodynamics Jones & Dugan
2. Thermodynamics An Engineering Approach Yunus Cengel & Boles /TMH
3. An introduction to Thermodynamics / YVC Rao / New Age
4. Engineering Thermodynamics K. Ramakrishna / Anuradha Publisher

OUTCOMES:

1. Analyze the work and heat interactions associated with a prescribed process path and to
perform a analysis of a flow system.
2. Quantify the irreversibilites associated with each possibility and choose an optimal cycle.
3. Able to analyse Mollier chart, and to find the quality of steam.
4. Able to analyze psychrometric chart, to estimate thermodynamic properties such as WBT,
DBT, RH, etc.
5. Analyze the thermodynamic cycles and evaluate performance parameters.

Department of Mechanical Engineering, MRCET Page iii

ENGINEERING THERMODYNAMICS B.TECH II YEAR I SEM R22

COURSE COVERAGE

S.NO NAME OF THE UNIT NAME OF THE TEXTBOOK CHAPTERS COVERED

Thermodynamics by P.K. Nag 1,2,3

1 Engineering Thermodynamics 1,2
Basic Concepts
K. Ramakrishna

2 Limitations of the First Thermodynamics by P.K. Nag 2,3,4

Law
Thermodynamics by P.K. Nag 3,4,5,6
3 Engineering Thermodynamics 4,5,6
Pure Substances
K. Ramakrishna

4 Mixtures of perfect Thermodynamics by P.K. Nag 3,4,5,6,7,8

Gases
5 Thermodynamics by P.K. Nag 7,8,9,10
Power Cycles

Department of Mechanical Engineering, MRCET Page iv

ENGINEERING THERMODYNAMICS B.TECH II YEAR I SEM R22

CONTENTS

S.No Name of the Unit Page No

1 Basic Concepts 2
2 Limitations of the First Law 18
3 Pure Substances 56
4 Mixtures of perfect Gases 73
5 Power Cycles 95
6 Question Bank 116
7 Case Study 123

Department of Mechanical Engineering, MRCET

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ENGINEERING THERMODYNAMICS B.TECH II YEAR I SEM R22

POs for Mechanical Engineering

Engineering knowledge: Apply the knowledge of mathematics, science, engineering
PO1 fundamentals, and an engineering specialization to the
solution of complex engineering problems.
Problem analysis: Identify, formulate, review research literature, and analyze complex
engineering problems reaching substantiated conclusions using first principles of mathematics,
PO2
natural sciences, and engineering
sciences.
Design/development of solutions: Design solutions for complex engineering problems and design
system components of processes that meet the specified needs with appropriate consideration
PO3 for the public
health and safety, and the cultural, societal, and environmental considerations.

Conduct investigations of complex problems: Use research-based knowledge and research

methods including design of experiments, analysis and interpretation of data, and synthesis of the
PO4
information to
provide valid conclusions.
Modern tool usage: Create, select, and apply appropriate techniques, resources, and modern
engineering and IT tools including prediction and modeling to complex engineering activities with
PO5
an understanding of the
limitations.
The engineer and society: Apply reasoning informed by the contextual knowledge to assess
societal, health, safety, legal and cultural issues and
PO6
the consequent responsibilities relevant to the professional engineering practice.

Environment and sustainability: Understand the impact of the professional engineering solutions
PO7 in societal and environmental contexts, and demonstrate the knowledge of, and need for
sustainable development.

Ethics: Apply ethical principles and commit to professional ethics and responsibilities and norms
PO8 of the engineering practice.
Individual and team work: Function effectively as an individual, and as a member or leader in
PO9 diverse teams, and in multidisciplinary settings.
Communication: Communicate effectively on complex engineering activities with the engineering
community and with society at large, such as, being able to comprehend and write effective
PO10 reports and design documentation, make effective presentations, and give and receive clear
instructions.

Project management and finance: Demonstrate knowledge and understanding of the engineering
PO11
team, to manage projects and in multidisciplinary environments.

Life-long learning: Recognize the need for, and have the preparation and ability to engage in
PO12 independent and life-long learning in the broadest context of technological change

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ENGINEERING THERMODYNAMICS B.TECH II YEAR I SEM R22
PSOs for Mechanical Engineering

PSO1 Ability to analyze, design and develop Mechanical systems to solve the Engineering
problems by integrating thermal, design and manufacturing domains.

PSO2 Ability to succeed in competitive examinations or to pursue higher studies or

research.

PSO3 Ability to apply the learned Mechanical Engineering knowledge for the development

of society and self.

PEOs for Mechanical Engineering

PEO1: PREPARATION The basic requirement for any student is

to become a successful graduate is to
To provide sound foundation in mathematical, have basic knowledge on fundamentals.
scientific and engineering fundamentals necessary Therefore, the first and foremost the
to analyze, formulate and solve engineering objective is defined as Preparation.
problems.

PEO2: CORE COMPETANCE Providing services as per the

Government & Industrial
To provide thorough knowledge in Mechanical development plans and thrust areas.
Engineering subjects including theoretical Considering reports and projections of
knowledge and practical training for preparing CII, ELIAP, AICTE, HRD, etc., on industrial
physical models about core field. developments requirements.

PEO3: INVENTION, INNOVATION AND Preparing students to solve complex

CREATIVITY engineering problems, which require
ideas about inventing, innovation and
To make the students to design,
experiment, analyze, and interpret in the core creativity.
field with the help of other inter disciplinary
concepts wherever applicable.

PEO4: CAREER DEVELOPMENT Preparing students to become a

successful person in his/her future.
To inculcate the habit of lifelonglearning for career
development through successful completion of
advanced
degrees, professional development courses,
industrial training etc.
PEO5: PROFESSIONALISM Preparing students to become a
successful entrepreneur who can meet
To impart technical knowledge, ethical values for the societal needs.
professional development of the student to solve
complex problems and to work in multi-
disciplinary ambience, whose solutions lead to
significant societal benefits.

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ENGINEERING THERMODYNAMICS B.TECH II YEAR I SEM R22

Blooms Taxonomy:

educators set for their students (learning objectives). The taxonomy was proposed
in 1956 by Benjamin Bloom, an educational psychologist at the University of
Chicago. The terminology has been recently updated to include the following six
levels of learning. These 6 levels can be used to structure the learning objectives,
lessons, and assessments of your course.
:

1. Remembering: Retrieving, recognizing, and recalling relevant knowledge

from long term memory.
2. Understanding: Constructing meaning from oral, written, and graphic
messages through interpreting, exemplifying, classifying, summarizing,
inferring, comparing, and explaining.
3. Applying: Carrying out or using a procedure for executing, or implementing.
4. Analyzing: Breaking material into constituent parts, determining how the
parts relate to one another and to an overall structure or purpose through
differentiating, organizing, and attributing.
5. Evaluating: Making judgments based on criteria and standards through
checking and critiquing.
6. Creating: Putting elements together to form a coherent or functional whole;
reorganizing elements into a new pattern or structure through generating,
planning, or producing.

Bloom's taxonomy is a set of three hierarchical models used to classify educational

learning objectives into levels of complexity and specificity. The three lists cover
the learning objectives in cognitive, affective and sensory domains. The cognitive
domain list has been the primary focus of most traditional education and is
frequently used to structure curriculum learning objectives, assessments and
activities.

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 ENGINEERING THERMODYNAMICS B.TECH II YEAR I SEM R22

Mapping of Course Objectives

Gain the knowledge on fluid mechanics fundamentals like fluid statics

C111.1 and fluid kinematics
Engineering Have basic idea about the fundamental equations used in Fluid
C111.2
Thermodyna Dynamics and are able to apply these concepts in real working
mics (C111) environment

Study the fundamentals of turbo machinery and elements of

C111.3
hydroelectric power plant.
C111.4 Measure the performance of the different types of Hydraulic Turbines
C111.5 Calculate the performance of the different types of Hydraulic Pumps.

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 ENGINEERING THERMODYNAMICS B.TECH II YEAR I SEM R22

UNIT I
Basics of thermodynamics:
S.I. SYSTEM
Sr. No. Physical quantities Unit symbol
1 Length Metre m
2 Mass Kilogram Kg
3 Time Second S
4 Temperature Kelvin K
Supplementary units of S.I. system

Sr. No. Physical Unit symbol

quantities
1 Plane angle Radian Rad
Principal S.I. units

Sr. Physical quantities Unit symbol

No.
1 Force Newton N
2 Work Joule J, N.m
3 Power Watt W
4 Energy Joule J, N.m
5 Area Square metre m2
6 Volume Cubic metre m3
7 Pressure Pascal Pa
8 Velocity/speed metre per second m/s
9 Acceleration metre/second2 m/s2
10 Angular velocity radian/second rad/s
11 Angular acceleration radian/second2 rad/s2
12 Momentum kilogram Kg.m/s
metre/second
13 Torque Newton metre N.m
14 Density Kilogram/metre3 Kg/m3
15 Couple Newton.metre N.m
16 Moment Newton.metre N.m
S.I. Prefixes

Multiplication factor Prefix Symble

1012 Tera T
109 Giga G
106 Mega M
103 kilo k
102 hecto h
101 deca da
10-1 deci d
10-2 centi c
10-3 milli m
10-6 micro µ
10-9 nano n
10-12 pico p

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ENGINEERING THERMODYNAMICS B.TECH II YEAR I SEM R22

Thermodynamics:
Thermodynamics is an axiomatic science which deals with the relations among heat, work and
properties of system which are in equilibrium. It describes state and changes in state of
physical systems.

System:

A thermodynamic system is defined as a quantity of matter or a region in space which is

selected for the study.

Surroundings:

The mass or region outside the system is called surroundings.

Boundary:

The real or imaginary surfaces which separates the system and surroundings is called
boundary. The real or imaginary surfaces which separates the system and surroundings is
called boundary.

Types of thermodynamic system

Based on mass and energy transfer the thermodynamic system is divided into three types.

1. Closed system
2. Open system
3. Isolated system

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ENGINEERING THERMODYNAMICS B.TECH II YEAR I SEM R22

Closed system: A system in which the transfer of energy but not mass can takes place across
the boundary is called closed system. The mass inside the closed system remains constant.

For example: Boiling of water in a closed vessel. Since the water is boiled in closed vessel so
the mass of water cannot escapes out of the boundary of the system but heat energy
continuously entering and leaving the boundary of the vessel. It is an example of closed
system.
Open system: A system in which the transfer of both mass and energy takes place is called an
open system. This system is also known as control volume.

For example: Boiling of water in an open vessel is an example of open system because the
water and heat energy both enters and leaves the boundary of the vessel.
Isolated system: A system in which the transfer of mass and energy cannot takes place is
called an isolated system.
For example: Tea present in a thermos flask. In this the heat and the mass of the tea cannot cross
the boundary of the thermos flask. Hence the thermos flak is an isolated system.

Control Volume:

a system of fixed volume.

volume"
Mass transfer can take place across a control volume.
Energy transfer may also occur into or out of the system.
Control Surface- the boundary of a control volume across which the transfer of
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ENGINEERING THERMODYNAMICS B.TECH II YEAR I SEM R22

both mass and energy takes place.

The mass of a control volume (open system) may or may not be xed.
When the net influx of mass across the control surface equals zero then the mass of
the system is fixed and vice-versa.
The identity of mass in a control volume always changes unlike the case for a control
mass system (closed system).
Most of the engineering devices, in general, represent an open system or control
volume.

Example:
Heat exchanger - Fluid enters and leaves the system continuously with the transfer of heat across
the system boundary.
Pump - A continuous flow of fluid takes place through the system with a transfer of mechanical
energy from the surroundings to the system.

Microscopic View or Study:

The approach considers that the system is made up of a very large number of discrete
particles known as molecules. These molecules have different velocities are energies.
The values of these energies are constantly changing with time. This approach to
thermodynamics, which is concerned directly with the structure of the matter, is
known as statistical thermodynamics.
The behavior of the system is found by using statistical methods, as the number of
molecules is very large. So advanced statistical and mathematical methods are needed
to explain the changes in the system.
The properties like velocity, momentum, impulse, kinetic energy and instruments
cannot easily measure force of impact etc. that describe the molecule.
Large numbers of variables are needed to describe a system. So the approach is

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ENGINEERING THERMODYNAMICS B.TECH II YEAR I SEM R22

complicated.
Macroscopic View or Study:
In this approach a certain quantity of matter is considered without taking into account
the events occurring at molecular level. In other words this approach to
thermodynamics is concerned with gross or overall behavior. This is known as classical
thermodynamics.
The analysis of macroscopic system requires simple mathematical formula.
The value of the properties of the system are their average values. For examples
consider a sample of gas in a closed container. The pressure of the gas is the average
value of the pressure exerted by millions of individual molecules.
In order to describe a system only a few properties are needed.

S.No Macroscopic Approach Microscopic Approach

In this approach a certain quantity of The matter is considered to be

1 matter is considered without taking comprised of a large number of tiny
into account the events occurring at particles known as molecules, which
molecular level. moves randomly in chaotic fashion.
The effect of molecular motion is
considered.
Analysis is concerned with overall The Knowledge of the structure of
behavior of the system. matter is essential in analyzing the
2
behavior of the system.
This approach is used in the study of This approach is used in the study of
3
classical thermodynamics. statistical thermodynamics.
A few properties are required to Large numbers of variables are
4
describe the system. required to describe the system.
The properties like pressure, The properties like velocity,
temperature, etc. needed to describe momentum, kinetic energy, etc.
the system, can be easily measured. needed to describe the system,
5 cannot be measured easily.

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ENGINEERING THERMODYNAMICS B.TECH II YEAR I SEM R22

The properties of the system are their The properties are defined for each
6
average values. molecule individually.
This approach requires simple No. of molecules are very large so it
mathematical formulas for analyzing requires advanced statistical and
the system. mathematical method to explain any
7 change in the system.

Thermodynamic Equilibrium:
A thermodynamic system is said to exist in a state of thermodynamic equilibrium when no
change in any macroscopic property is registered if the system is isolated from its
surroundings.
An isolated system always reaches in the course of time a state of thermodynamic equilibrium
and can never depart from it spontaneously.
Therefore, there can be no spontaneous change in any macroscopic property if the system
exists in an equilibrium state. A thermodynamic system will be in a state of thermodynamic
equilibrium if the system is the state of Mechanical equilibrium, Chemical equilibrium and
Thermal equilibrium.
Mechanical equilibrium: The criteria for Mechanical equilibrium are the equality of
pressures.
Chemical equilibrium: The criteria for Chemical equilibrium are the equality of
chemical potentials.
Thermal equilibrium: The criterion for Thermal equilibrium is the equality of
temperatures.
State:

The thermodynamic state of a system is defined by specifying values of a set of measurable

properties sufficient to determine all other properties. For fluid systems, typical properties
are pressure, volume and temperature. More complex systems may require the specification
of more unusual properties. As an example, the state of an electric battery requires the
specification of the amount of electric charge it contains.

Property:

Properties may be extensive or intensive.

Intensive properties: The properties which are independent of the mass of the
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ENGINEERING THERMODYNAMICS B.TECH II YEAR I SEM R22

system. For example: Temperature, pressure and density are the intensive
properties.
Extensive properties: The properties which depend on the size or extent of the system
are called extensive properties.
For example: Total mass, total volume and total momentum.
Process:

When the system undergoes change from one thermodynamic state to final state due change
in properties like temperature, pressure, volume etc, the system is said to have undergone
thermodynamic process.
Various types of thermodynamic processes are: isothermal process, adiabatic process,
isochoric process, isobaric process and reversible process.

Cycle:

Thermodynamic cycle refers to any closed system that undergoes various changes due to
temperature, pressure, and volume, however, its final and initial state are equal. This cycle is
important as it allows for the continuous process of a moving piston seen in heat engines and
the expansion/compression of the working fluid in refrigerators, for example. Without the
cyclical process, a car wouldn't be able to continuously move when fuel is added, or a
refrigerator would not be able to stay cold. Visually, any thermodynamic cycle will appear as
a closed loop on a pressure volume diagram.
Examples: Otto cycle, Diesel Cycle, Brayton Cycle etc.
Reversibility:

Reversibility, in thermodynamics, a characteristic of certain processes (changes of a system

from an initial state to a final state spontaneously or as a result of interactions with other
systems) that can be reversed, and the system restored to its initial state, without leaving net
effects in any of the systems involved.
An example of a reversible process would be a single swing of a frictionless pendulum from
one of its extreme positions to the other. The swing of a real pendulum is irreversible because
a small amount of the mechanical energy of the pendulum would be expended in performing
work against frictional forces, and restoration of the pendulum to its exact starting position
would require the supply of an equivalent amount of energy from a second system, such as a
compressed spring in which an irreversible change of state would occur.
Quasi static process:
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ENGINEERING THERMODYNAMICS B.TECH II YEAR I SEM R22

When a process is processing in such a way that system will be remained infinitesimally close
with equilibrium state at each time, such process will be termed as quasi static process or
quasi equilibrium process.
In simple words, we can say that if system is going under a thermodynamic process through
succession of thermodynamic states and each state is equilibrium state then the process will
be termed as quasi static process.

We will see one example for understanding the quasi static process, but let us consider one
simple example for better understanding of quasi static process. If a person is coming down
from roof to ground floor with the help of ladder steps then it could be considered as quasi
static process. But if he jumps from roof to ground floor then it will not be a quasi static
process.
Weight placed over the piston is just balancing the force which is exerted in upward direction
by gas. If we remove the weight from the piston, system will have unbalanced force and piston
will move in upward direction due to force acting over the piston in upward direction by the
gas.
Irreversible Process:

The irreversible process is also called the natural process because all the processes occurring
in nature are irreversible processes. The natural process occurs due to the finite gradient
between the two states of the system. For instance, heat flow between two bodies occurs

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ENGINEERING THERMODYNAMICS B.TECH II YEAR I SEM R22

due to the temperature gradient between the two bodies; this is in fact the natural flow of
heat. Similarly, water flows from high level to low level, current moves from high potential to
low potential, etc.
In the irreversible process the initial state of the system and surroundings cannot be
restored from the final state.
During the irreversible process the various states of the system on the path of change
from initial state to final state are not in equilibrium with each other.
During the irreversible process the entropy of the system increases decisively and it
cannot be reduced back to its initial value.
The phenomenon of a system undergoing irreversible process is called as
irreversibility.

Causes of Irreversibility:
Friction: Friction is invariably present in real systems. It causes irreversibility in the process as
work done does not show an equivalent rise in the kinetic or potential energy of the system.
The fraction of energy wasted due to frictional effects leads to deviation from reversible
states.
Free expansion: Free expansion refers to the expansion of unresisted type such as expansion
in a vacuum. During this unresisted expansion the work interaction is zero, and without the
expense of any work, it is not possible to restore initial states. Thus, free expansion is
irreversible.
Heat transfer through a finite temperature difference: Heat transfer occurs only when there
exists temperature difference between bodies undergoing heat transfer. During heat transfer,
if heat addition is carried out in a finite number of steps then after every step the new state
shall be a non-equilibrium state.
Non equilibrium during the process: Irreversibilities are introduced due to lack of
thermodynamic equilibrium during the process. Non-equilibrium may be due to mechanical
inequilibrium, chemical inequilibrium, thermal inequilibrium, electrical inequilibrium, etc. and
irreversibility is called mechanical irreversibility, chemical irreversibility, thermal
irreversibility, electrical irreversibility respectively. Factors discussed above are also causing
non-equilibrium during the process and therefore make process irreversible.
Heat:
It is the energy in transition between the system and the surroundings by virtue of the
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ENGINEERING THERMODYNAMICS B.TECH II YEAR I SEM R22

difference in temperature Heat is energy transferred from one system to another solely by
reason of a temperature difference between the systems. Heat exists only as it crosses the
boundary of a system and the direction of heat transfer is from higher temperature to lower
temperature. For thermodynamics sign convention, heat transferred to a system is positive;
Heat transferred from a system is negative.

Work:
Thermodynamic definition of work: Positive work is done by a system when the sole effect
external to the system could be reduced to the rise of a weight.
Work done by the system is positive and work done on the system is negative.

Types of work interaction:

Expansion and compression work (displacement work)
Work of a reversible chemical cell
Work in stretching of a liquid surface
Work done on elastic solids
Work of polarization and magnetization

15