This document provides an overview of the course MCT-114: Fundamentals of Thermal Sciences. The objectives of the course are to provide a solid grounding in engineering thermodynamics and its fundamental concepts. Topics covered include the basic concepts, laws of energy, ideal gas model, entropy, and power/refrigeration cycles. The course also introduces heat transfer concepts. The document outlines the suggested textbooks, course learning objectives, and provides an introduction to thermal-fluid sciences, thermodynamics, heat transfer, and fluid mechanics.

1. MCT-114: FUNDAMENTALS
OF THERMAL SCIENCES
LECTURE 1

2. COURSE OBJECTIVES:
The objective of this course is to provide a solid grounding in the theory of
engineering thermodynamics. The emphasis is on the fundamental concepts
(such as temperature, pressure, internal energy, energy transfer by heat,
work, enthalpy, and properties of a pure substance), First and Second laws
of thermodynamics, entropy, power & refrigeration cycles and engineering
application of thermodynamics. It is expected that the students are
challenged in terms of their understanding of the physical concepts, their
related mathematical and engineering skills, and most importantly, their
passion for studying thermal sciences and engineering.

3. TOPICS COVERED:
Introduction: Basic concepts of thermodynamics, properties of pure
substances
Laws of Energy: energy transfer by heat, work and mass, the first law
of thermodynamics, evaluating properties (steam tables, Z chart),
introducing ideal gas model, the second law of thermodynamics,
entropy, power and refrigeration cycles
Introduction to Heat Transfer: heat transfer, steady heat conduction,
transient heat conduction, forced convection, natural convection,
fundamentals of thermal radiation, radiation heat transfer.

4. SUGGESTED TEXT:
 Fundamentals of Engineering Thermodynamics by Michael J. Moran and Howard
N. Shapiro
 Fundamentals of thermal-fluid sciences by Cengel and Turner (McGraw-Hill)

5. COURSE LEARNING
OBJECTIVES (CLOS)
1. Explain the fundamental concepts of applied thermodynamics and heat
transfer
2. Apply the laws and equations of thermodynamics and heat transfer to
perform basic calculations related to thermodynamics processes and
cycles (including heat, work, efficiency etc.)
3. Use tables, generalized compressibility chart and ideal gas model for
determining properties of pure substances.

6. INTRODUCTION
TO THERMAL-
FLUID SCIENCES
• The word thermal stems from the Greek word therme,
which means heat. Therefore, thermal sciences can be
defined as the sciences that deal with heat.
• Thermal-fluid sciences ( or simply thermal sciences):
The physical sciences that deal with energy and the
transfer, transport, and conversion of energy.
• Thermal-fluid sciences are studied under the
subcategories of
• thermodynamics
• heat transfer
• fluid mechanics
6

7. The design and analysis of most thermal systems such as power plants,
automotive engines, and refrigerators involve all categories of
thermal-fluid sciences as well as other sciences.
For example, designing the radiator of a car involves the
 Determination of the amount of energy transfer from a knowledge of the
properties of the coolant using thermodynamics,
 The determination of the size and shape of the inner tubes and the
outer fins using heat transfer,
 The determination of the size and type of the water pump using fluid
mechanics.
Of course, the determination of the materials and the thickness of the
tubes requires the use of material science as well as strength of materials.

8. All activities in nature involve some interaction between energy and matter; thus it is hard to imagine an
area that does not relate to thermal-fluid sciences in some manner.

9. 9
THERMODYNAMICS
Thermodynamics: The science of energy.
Energy: The ability to cause changes.
The name thermodynamics stems from the Greek words therme
(heat) and dynamis (power).
convert heat into power.
Power :The ability or capacity to do something or act
in a particular way.
Thermodynamics is a science and, more importantly,
an engineering tool used to describe processes that
involve changes in temperature, transformation of
energy, and the relationships between heat and work.

10. 10
HEAT TRANSFER
Heat: The form of energy that can be
transferred from one system to another
as a result of temperature difference.
Heat Transfer: The science that deals
with the determination of the rates of
such energy transfers and variation of
temperature.
Thermodynamics is concerned with the
amount of heat transfer as a system
undergoes a process from one
equilibrium state to another, and it gives
no indication about how long the
process will take. But in engineering, we
are often interested in the rate of heat
transfer, which is the topic of the
science of heat transfer.

11. 11
One of the most fundamental laws of nature is the:
Conservation of energy principle: During an interaction, energy
can change from one form to another but the total amount of
energy remains constant.
Energy cannot be created or destroyed.
A rock falling off a cliff, for example, picks up speed as a result of
its potential energy being converted to kinetic energy.
The change in the energy content of a body or any other system is
equal to the difference between the energy input and the energy
output, and the energy balance is expressed as Ein - Eout = ∆E.
The second law of thermodynamics: It asserts that energy has
quality as well as quantity, and actual processes occur in the
direction of decreasing quality of energy.
For example, a cup of hot coffee left on a table eventually cools,
but a cup of cool coffee in the same room never gets hot by itself.
The high-temperature energy of the coffee is degraded
(transformed into a less useful form at a lower temperature) once
it is transferred to the surrounding air.
Heat flows in the direction of
decreasing temperature.

12. Thermodynamics deals with equilibrium states and changes from one
equilibrium state to another. Heat transfer, on the other hand, deals with
systems that lack thermal equilibrium, and thus it is a nonequilibrium
phenomenon.
Therefore, the study of heat transfer cannot be based on the principles of
thermodynamics alone. However, the laws of thermodynamics lay the
framework for the science of heat transfer. The first law requires that the rate of
energy transfer into a system be equal to the rate of increase of the energy of
that system. The second law requires that heat be transferred in the direction of
decreasing temperature

13. The basic requirement for heat transfer is the presence of a temperature difference. There
can be no net heat transfer between two bodies that are at the same temperature. The
temperature difference is the driving force for heat transfer, just as the voltage difference is
the driving force for electric current flow and pressure difference is the driving force for fluid
flow. The rate of heat transfer in a certain direction depends on the magnitude of the
temperature gradient (the temperature difference per unit length or the rate of change of
temperature) in that direction. The larger the temperature gradient, the higher the rate of
heat transfer.

14. 14
FLUID MECHANICS
Fluid mechanics: The science
that deals with the behavior of
fluids at rest (fluid statics) or in
motion (fluid dynamics), and the
interaction of fluids with solids or
other fluids at the boundaries.
Fluid: A substance in the liquid or
gas phase.
A solid can resist an applied shear
stress by deforming, whereas a
fluid deforms continuously under
the influence of shear stress, no
matter how small.
Fluid mechanics deals with liquids
and gases in motion or at rest.

15. It is well-known that a substance consists of a large
number of particles called molecules. The properties
of the substance naturally depend on the behavior of
these particles. For example, the pressure of a gas in
a container is the result of momentum transfer
between the molecules and the walls of the
container. However, one does not need to know the
behavior of the gas particles to determine the
pressure in the container. It would be sufficient to
attach a pressure gage to the container. This
macroscopic approach to the study of
thermodynamics that does not require a knowledge
of the behavior of individual particles is called
classical thermodynamics. It provides a direct and
easy way to the solution of engineering problems. A
more elaborate approach, based on the average
behavior of large groups of individual particles, is
called statistical thermodynamics. This microscopic
approach is rather involved and is used in this text
only in the supporting role.

16. IMPORTANCE OF DIMENSIONS AND
UNITS:
Any physical quantity can be characterized by dimensions.
The magnitudes assigned to the dimensions are called units.
Some basic dimensions such as mass m, length L, time t, and
temperature T are selected as primary or fundamental dimensions,
while others such as velocity V, energy E, and volume V are expressed
in terms of the primary dimensions and are called secondary
dimensions, or derived dimensions.
Metric SI system: A simple and logical system based on a decimal
relationship between the various units.
English system: It has no apparent systematic numerical base, and
various units in this system are related to each other rather
arbitrarily(12 in = 1 ft, 1 mile = 5280 ft, etc).

17. SOME SI AND ENGLISH UNITS:

18. PROBLEM SOLVING
TECHNIQUE:
Step 1: Problem Statement
In your own words, briefly state the problem, the key information given,
and the quantities to be found. This is to make sure that you understand the
problem and the objectives before you attempt to solve the problem.
Step 2: Schematic
Draw a realistic sketch of the physical system involved, and list the relevant
information on the figure. Indicate any energy and mass interactions with the
surroundings. Also, check for properties that remain constant during a
process (such as temperature during an isothermal process), and indicate
them on the sketch.
Step 3: Assumptions and Approximations
State any appropriate assumptions and approximations made to simplify
the problem to make it possible to obtain a solution. For example, in the absence of
specific data for atmospheric pressure, it can be taken to be 1 atm.

19. Step 4: Physical Laws
Apply all the relevant basic physical laws and principles (such as the conservation of mass), and reduce them to
their simplest form by utilizing the assumptions made. However, the region to which a physical law is applied must
be clearly identified first. For example, the increase in speed of water flowing through a nozzle is analyzed by
applying conservation of mass between the inlet and outlet of the nozzle.
Step 5: Properties
Determine the unknown properties at known states necessary to solve the problem from property relations or tables.
Step 6: Calculations
Substitute the known quantities into the simplified relations and perform the calculations to determine the unknowns.
Step 7: Reasoning, Verification, and Discussion
Check to make sure that the results obtained are reasonable and intuitive, and verify the validity of the questionable
assumptions. Repeat the calculations that resulted in unreasonable values.

20. SYSTEMS AND CONTROL VOLUMES:
The system is whatever we want to study. It may be as simple as a free body or as complex as an
entire chemical refinery.
A system is defined as a quantity of matter or a region in space chosen for study. The mass or region
outside the system is called the surroundings.
The real or imaginary surface that separates the system from its surroundings is called the boundary.
The boundary of a system can be fixed or movable.
Note that the boundary is the contact surface shared by both the system and the surroundings.
Closed system or control mass
Open system or control volume

21. Closed system or control mass: consists of a fixed amount of mass, and no mass can
cross its boundary. But, energy in the form of heat or work, can cross the boundary,
and the volume of a closed system does not have to be fixed.
A closed system is defined when a particular quantity of matter is
under study. A closed system always contains the same matter. There
can be no transfer of mass across its boundary
Isolated system: A closed system that does not communicate with the surroundings
by any means.
Rigid system: A closed system that communicates with the surroundings by heat only.

22. When the valves are closed, we can consider the gas to be a closed
system. The boundary lies just inside the piston and cylinder walls, as
shown by the dashed lines on the figure. Since the portion of the
boundary between the gas and the piston moves with the piston, the
system volume varies. No mass would cross this or any other part of the
boundary. If combustion occurs, the composition of the system changes
as the initial combustible mixture becomes products of combustion.

23. Open system or control volume: is a properly selected region in space. It usually encloses a device that involves mass
flow such as a compressor, turbine, or nozzle. Flow through these devices is best studied by selecting the
region within the device as the control volume. Both mass and energy can cross the boundary of a control
volume.
The boundaries of a control volume are called a control surface, and they can be real or imaginary.
In the case of a nozzle, the inner surface of the nozzle forms the real part of the boundary, and the
entrance and exit areas form the imaginary part, since there are no physical surfaces.

24. Let us say that we would like to determine how much heat we
must transfer to the water in the tank in order to supply a steady stream of
hot water. Since hot water will leave the tank and be replaced by cold water,
it is not convenient to choose a fixed mass as our system for the analysis.
Instead, we can concentrate our attention on the volume formed by the
interior surfaces of the tank and consider the hot and cold water streams as
mass leaving and entering the control volume. The interior surfaces of the
tank form the control surface for this case, and mass is crossing the control
surface at two locations.

25. It is well-known that a substance consists of a large number of particles called molecules. The properties
of the substance naturally depend on the behavior of these particles. For example, the pressure of a gas
in a container is the result of momentum transfer between the molecules and the walls of the container.
However, one does not need to know the behavior of the gas particles to determine the pressure in the
container. It would be sufficient to attach a pressure gage to the container.
Systems can be studied from a macroscopic or a microscopic point of view.
Classical thermodynamics: A macroscopic approach to the study of thermodynamics that does not
require a knowledge of the behavior of individual particles.
Statistical thermodynamics: A microscopic approach, based on the average behavior of large groups of
individual particles.
The objective of statistical thermodynamics is to characterize by statistical means the average behavior of
the particles making up a system of interest and relate this information to the observed macroscopic
behavior of the system. For applications involving lasers, plasmas, high speed gas flows, chemical
kinetics, very low temperatures (cryogenics), and others, the methods of statistical thermodynamics are
essential.

26. PROPERTY, STATE, AND PROCESS:
To describe a system and predict its behavior requires knowledge of its properties and how
those properties are related.
Property is a macroscopic characteristic of a system such as mass, volume, energy,
pressure, and temperature to which a numerical value can be assigned at a given time without
knowledge of the previous behaviour (history) of the system.
The word state refers to the condition of a system as described by its properties. When any of
the properties of a system changes, the state changes and the system is said to undergo a
process.
A process is a transformation from one state to another. If a system exhibits the same values
of its properties at two different times, it is in the same state at these times. A system is said to
be at steady state if none of its properties changes with time.

27. Thermodynamic properties can be placed in two general classes: extensive and
intensive.
Extensive Property: A property is called extensive if its value for an overall
system is the sum of its values for the parts into which the system is divided.
Mass, volume, energy, and several other properties introduced later are extensive.
Extensive properties depend on the size or extent of a system. The extensive
properties of a system can change with time.
Intensive properties: They are not additive in the sense previously considered.
Their values are independent of the size or extent of a system and may vary from
place to place within the system at any moment.
Intensive properties may be functions of both position and time, whereas
extensive properties can vary only with time. Specific volume pressure, and
temperature are important intensive properties.

29. CONTINUUM:
The number of molecules involved is immense, and the separation
between them is normally negligible by comparison with the
distances involved in the practical situation being studied.
Under these conditions, it is usual to consider a fluid as a continuum
– a hypothetical
continuous substance – and the conditions at a point as the average
of a very
large number of molecules surrounding that point within a distance
which is large
compared with the mean intermolecular distance (although very small
in absolute
terms).

30. FLUID PROPERTIES:
Density: The density of a substance is that quantity of matter contained in unit volume of
the substance.
Mass density ρ is defined as the mass of the substance per unit volume.
The density of a substance, in general, depends on temperature and pressure. The density of most
gases is proportional to pressure and inversely proportional to temperature. Liquids and solids, on the
other hand, are essentially incompressible substances, and the variation of their density with pressure
is usually negligible.

32. Specific Weight: Specific weight w is defined as the weight per unit volume.
Since weight is dependent on gravitational attraction, the specific weight will
vary from point to point, according to the local value of gravitational
acceleration g.

33. Relative Density: Relative density (or specific gravity) σ is defined as the ratio of the
density of a substance to the density of some standard substance
at a specified temperature.
o For liquid standard fluid is water at 4°C.
o For gas, the standard fluid is air.
Note that the specific gravity of a substance is a dimensionless quantity.

34. EQUILIBRIUM:
The word equilibrium implies a state of balance. In an equilibrium
state there are no unbalanced potentials (or driving forces) within the
system. A system in equilibrium experiences no changes when it is
isolated from its surroundings.
Thermal equilibrium if the temperature is the same throughout the
entire system

35. Mechanical equilibrium is related to pressure, and a system is in mechanical
equilibrium if there is no change in pressure at any point of the system with
time.
If a system involves two phases, it is in phase equilibrium when the mass of
each phase reaches an equilibrium level and stays there.
A system is in chemical equilibrium, if its chemical composition does not
change with time, that is, no chemical reactions occur.
A system will not be in equilibrium unless all the relevant equilibrium
criteria are satisfied.