Introduction

Heat and Mass Transfer – ME 315

Rishi Raj

ME 315 © rraj@iitp.ac.in Courtesy: Wiley 1

 Course Information

❑L-T-P-C : 3-0-2-8

❑Instructor: Dr. Rishi Raj (rraj@iitp.ac.in)

❑Course Website: Microsoft Teams Page and

https://cciitpatna.sharepoint.com/sites/ME315Fall2020

❑Class Timing and Doubt Hours: Tuesday, Wednesday and

Friday: 9 AM – 10 AM, Thursday: 10 AM – 11 AM)

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ME 315 © rraj@iitp.ac.in Courtesy: Wiley 3
 Course Objectives

The five broad learning objectives for this course are

1. The student should internalize the meaning of the terminology and physical
principles associated with heat and mass transfer processes.
2. The student should be able to delineate pertinent transport phenomena for any
process or system involving heat or mass transfer.
3. The student should be able to use requisite inputs for computing heat transfer rates
and/or material temperatures.
4. The student should be able to develop representative models of real processes and
systems and draw conclusions concerning process/system design or performance.
5. The student should become familiar with design of heat transfer experiments and
concerning measurement techniques.

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 Textbooks and References

❑Text Book:
1. F.P. Incropera, D.P. Dewitt, T. L. Bergman, and A. S. Lavine,
Fundamentals of Heat and Mass Transfer, 6th Edition, John Wiley and
Sons. 2007.

❑Reference Books:
1. J.P. Holman, Heat Transfer, 8th Edition, McGraw Hill, 1997.
2. M.N. Ozisik, Heat Transfer – A basic approach, McGraw Hill, 1985.
3. Bejan, Convection Heat Transfer, 2nd Edition, Interscience, 1994.
4. Y. A. Cengel, Heat and Mass Transfer, 3rd Edition, Tata McGraw-Hill, New
Delhi, 2007.

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 Syllabus
Lect. No. Topic Objectives Chapter/Section
Module 0
1-2 Introduction to Heat This chapter sets the stage for any discussion of heat 1
and Mass Transfer and transfer. It explains the science-based linkage between
Relationship to thermodynamics and heat transfer, and fluid mechanics
Thermodynamics and and heat transfer.
Fluid Mechanics
Module 1 – 35%
3-5 Introduction This chapter introduces the details of first mode of heat 2
to Conduction transfer, i.e., conduction. It covers the conduction rate (Section 2.2 will not be
equation (Fourier’s law), the heat diffusion equation, and the covered in depth)
significance of boundary and initial conditions.
6-9 One-Dimensional This chapter includes discussion of thermal resistance 3.1, 3.3, 3.5, and 3.6
Steady-State network analysis in linear and radial systems, conduction
Conduction with thermal energy generation, and heat transfer from
extended surfaces.
10-13 Two-Dimensional, This chapter will introduce method of separation of variable 4
Steady-State for solving two-dimensional problems. We will also discuss MATLAB Assignment 1
Conduction the conduction shape factor and fine difference formulation.
14-16 Transient Conduction Lumped capacitance analysis will be discussed, Biot and 5
Fourier numbers will be introduced, and heat conduction in (Section 5.9 will not be
semi-infinite solids will be discussed. Finite difference covered in depth)
formulation to transient problems will be introduced. MATLAB Assignment 2
Module 2 – 35%
17-20 Introduction to Convection boundary layers, local and average heat 6
Convection transfer coefficients, turbulent flow, boundary layer
equations, dimensionless parameters, mass transfer
analogy – details of mass transfer as discussed in chapter
14 will be skipped as an optional reading material
21-24 External Flow Empirical method, flat plate in parallel flow, cylinder in cross 7.1-7.5
flow, and flow over sphere
Mid-Sem Examination
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 Syllabus
Mid-Sem Examination
25-29 Internal Flow Hydrodynamic and thermal considerations, thermal 8.1-8.6
considerations, energy balance, laminar flow in circular
tubes, introduction to turbulent flows and non-circular tube
shapes
30-32 Free Convection Governing equation for boundary layers, similarity analysis, 9.1-9.6
vertical surface, empirical correlations
Module 3 – 10%
33 Boiling, Condensation, Introduction to liquid-vapor heat transfer, current research 10.1-10.6 as reading
and Advanced Topics problems material
34-37 Heat Exchangers Overall heat transfer coefficient, LMTD, NTU Method (will 11.1-11.4
be supplemented through laboratory classes)
Module 4 – 20%
38-43 Introduction to Radiation heat flux, intensity, blackbody, emission from real 121-12.8
Radiation surfaces, absorption, reflection, and transmission,
Kirchhoff’s law, Gray surface
44-47 Radiation Exchange View factor, black body radiation exchange, radiation 13.1-13.3
Between Surfaces exchange between opaque, diffuse, gray surfaces in an
enclosure
End-Sem Examination

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 Experiments (To be conducted later)

1. Measurement of thermal conductivity of different materials using composite

wall apparatus – Module 1
2. Unsteady heat conduction experiment – Module 1
3. Determination of the convective heat transfer coefficient in (a) natural and
(b) forced convection – Module 2
4. Performance evaluation of double pipe heat exchanger for (a) parallel flow
(b) counter flow – Module 3
5. Performance evaluation of shell-and-tube heat exchanger – Module 3
6. Phase change heat transfer: (a) Pool boiling, (b) Condensation – Module 3
7. Emissivity measurement – Module 4

(Suitable candidates for Engineering Practicum)

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 Schedule
Total Number of Contact Hours as per Time Table: 35
Doubt Sessions + Extra Classes: 12 Thursday 10 AM – 11 AM)
No. of Laboratory Sessions: 10 (to be conducted later)
August 2020 September 2020
Sun Mon Tue Wed Thu Fri Sat Sun Mon Tue Wed Thu Fri Sat
1 2 X 4

14 8 9 X 11

18 19 X 21 15 16 X 18

25 26 X 28 22 23 X 25

MID SEM WEEK

October 2020 November 2020

Sun Mon Tue Wed Thu Fri Sat Sun Mon Tue Wed Thu Fri Sat
6 7 X 9 3 4 X 6

13 14 X 16 10 11 X 13

17 18 X

27 28 X END SEM WEEK

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 PLAGIARISM DECLARATION

1. I know that plagiarism means copying and submitting assignments, quizzes,

tutorials, and examination papers of another as if they were one’s own. I know that
plagiarism covers this sort of use of material found in textual sources and from the
Internet.
2. I acknowledge and understand that plagiarism is wrong and is unfair to the
hardworking fellow students who have spent their time and effort for these
submissions.
3. I pledge/declare that I will not use any such unfair means for this course ME 315.
Failing to abide by these, I may suitably be penalized and debarred from continuing
in the course.

ME 315 © rraj@iitp.ac.in Courtesy: Wiley 10

 IN-CLASS CONDUCT

1. I understand that attending lectures regularly is an integral part of the IIT System.
2. I understand that the 10% weightage for day today performance and sincerity will be
based on student’s attendance and in class participation.
3. All students must MUTE themselves during the entire duration of class.
4. Doubts are encouraged and will be answered in class. You will need to UNMUTE
yourself and seek instructor’s attention. The instructor may ask you to turn your video
ON, if required.
5. Regular questions will be asked to check in-class sincerity. The response to these
questions will be noted and used towards the 10% weightage.

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 Grading Scheme

❑ Mid-Semester Assignment + VIVA: 15 %

❑ End-Semester Assignment + VIVA: 15 %
❑ Regular Assignments + VIVA: 30 %
❑ Day to day performance and Sincerity: 10 %
❑ Laboratory: 30% (to be conducted later)

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 Submissions
1. All assignment questions will be uploaded on Microsoft Teams. No emails will be sent. It
is the responsibility of the student to not miss any deadlines.

2. All assignment submissions will be uploaded individually by each student using their
Microsoft Teams account.

3. Being able to explain/defend assignment solutions in the VIVA will carry majority of the
weightage in the evaluation.

4. Grades will only be awarded after the soft copy of the assignment submitted online is
matched later with the hard copy when students come back to the campus.

5. Accordingly, all students are required to solve all assignment in one NOTEBOOK which
will subsequently be submitted for evaluation when they come back to the campus.

6. MATLAB/EXCEL will be required for certain assignments.

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 Assignment 1

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 Teaching Style

1. I will mostly use white board teaching equivalent in the ONLINE mode.

2. Students are expected to take notes during the live ONLINE classes.

3. Some sections heavy on graphical description/charts will be covered with

the help of power point slides.

4. Reading assignments from the course textbook will be assigned from time
to time.

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 Chapter 1: Introduction

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 Heat
❑Heat is defined as the form of energy that is transferred across the
boundary of a system at a given temperature to another system (or the
surroundings) at a lower temperature by virtue of the temperature
difference between the two systems.

❑A body never contains heat.

❑Heat, like work, is a form of energy transfer to or from a system.

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 Heat (and Mass) Transfer and
Thermodynamics
❑The two ways in which the internal energy of a system can be
changed are
❑ Work – Applied Thermodynamics (Flow work) – ME 314
❑ Heat Engine

❑ Refrigerator

❑ Heat Pump

❑ Heat Transfer – ME 315

❑ Conduction, Convection, and Radiation

❑ Mass Transfer – ME 315

❑ Due to concentration gradient – diffusion ( fundamentally similar to conduction)

❑ Flow (not referred to as Mass Transfer) – Fluid Mechanics – ME 216

❑ Due to bulk flow

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 Heat and Work

❑Heat and work are both transient phenomena. Systems never possess
heat or work, but either or both cross the system boundary when a system
undergoes a change of state.

❑Both heat and work are boundary phenomena. Both are observed only at
the boundary of the system, and both represent energy crossing the
boundary.

❑Both heat and work are path functions and inexact differentials.

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 First Law of Thermodynamics

❑The first law of thermodynamics states that during any cycle a system (control
mass) undergoes, the cyclic integral of the heat is proportional to the cyclic
integral of the work.

❑For processes
❑ 𝑈2 − 𝑈1 = 𝑄1→2 − 𝑊1→2

❑ 𝑑𝑈 = 𝛿𝑄 − 𝛿𝑊

❑General formulation
2 2
𝑑𝐸C.V. 𝑉 𝑉
❑ ሶ −𝑊C.V.
= 𝑄C.V. ሶ − σ 𝑚ሶ 𝑒 ℎ𝑒 + 𝑒 + 𝑔𝑍𝑒 + σ 𝑚ሶ 𝑖 ℎ𝑖 + 𝑖 + 𝑔𝑍𝑖
𝑑𝑡 2 2

❑ Associated with (flow) work – dealt in Applied Thermodynamics – ME 314

❑ Turbine
❑ Compressor

❑ Pumps

❑ Nozzles…..

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 Second Law of Thermodynamics

❑The Kelvin–Planck statement: It is impossible to construct a device that

will operate in a cycle and produce no effect other than the raising of a
weight and the exchange of heat with a single reservoir.

❑The Clausius statement: It is impossible to construct a device that

operates in a cycle and produces no effect other than the transfer of heat
from a cooler body to a hotter body.

❑Heat is defined as the form of energy that is transferred across the

boundary of a system at a given temperature to another system (or the
surroundings) at a lower temperature by virtue of the temperature
difference between the two systems. – Clausius statement

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 Heat Transfer and Thermal Energy

What is heat transfer?

Heat transfer is thermal energy in transit due to a temperature difference.

What is thermal energy?

Thermal energy is associated with the translation, rotation, vibration and

electronic states of the atoms and molecules that comprise matter. It
represents the cumulative effect of microscopic activities and is directly
linked to the temperature of matter.

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 Heat Transfer and Thermal Energy (cont.)
DO NOT confuse or interchange the meanings of Thermal Energy, Temperature and Heat Transfer

Quantity Meaning Symbol Units

Thermal Energy+ Energy associated with microscopic U or u J or J/kg

behavior of matter

Temperature A means of indirectly assessing the

amount of thermal energy stored in T K or °C
matter

Heat Transfer Thermal energy transport due to

temperature gradients

Heat Amount of thermal energy transferred Q J

over a time interval  t  0

Heat Rate Thermal energy transfer per unit time q W

Heat Flux Thermal energy transfer per unit time q  W/m 2

and surface area

𝑈 → Thermal energy of system

ME 315 © rraj@iitp.ac.in Courtesy: Wiley 𝑢 → Thermal energy per unit mass of system 23
 Modes of Heat Transfer

Conduction: Heat transfer in a solid or a stationary fluid (gas or liquid) due to the random motion of its
constituent atoms, molecules and /or electrons.

Convection: Heat transfer due to the combined influence of bulk and random motion for fluid flow over a
surface.

Radiation: Energy that is emitted by matter due to changes in the electron configurations of its atoms or
molecules and is transported as electromagnetic waves (or photons).

• Conduction and convection require the presence of temperature variations in a material medium.

• Although radiation originates from matter, its transport does not require a material medium
and occurs most efficiently in a vacuum.

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 Heat (and Mass) Transfer and
Thermodynamics

❑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.

❑A thermodynamic analysis simply tells us how much heat

must be transferred to realize a specified change of state to
satisfy the conservation of energy principle.

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 Heat (and Mass) Transfer and
Thermodynamics
❑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 non-equilibrium
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.

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 Heat (and Mass) Transfer and
Thermodynamics
❑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. It is analogous to the
electric current flowing in the direction of decreasing voltage
or the fluid flowing in the direction of decreasing pressure.

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 Heat (and Mass) Transfer and
Thermodynamics
❑While thermodynamics covers the end states of processes, heat transfer
tells us about the nature and rate of movements of thermal energy within
the process.

❑Understanding and controlling heat (thermal energy) is critical for many

engineering systems. This course covers the fundamentals of heat
transfer from a macroscopic perspective and aims to develop a physical
and analytical understanding of the three modes of heat transfer
(conduction, convection, radiation), with an emphasis on modeling and
simplifying approximations to solve real-world engineering problems.

❑Examples are taken from several fields including manufacturing,

electronics, consumer products, and energy systems.
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 Heat (and Mass) Transfer and
Thermodynamics

❑In practice, we are concerned with the rate of heat transfer

(heat transfer per unit time) than we are with the amount of
heat transfer.
❑ For example, we can determine the amount of heat transferred from a
thermos flask as the hot milk inside cools from 95 ℃ to 85 ℃ by a
thermodynamic analysis alone. But, a designer of the thermos flask is
primarily interested in how long it will be before the hot milk inside cools 85 ℃,
and a thermodynamic analysis cannot answer this question.

❑ Determining the rates of heat transfer to or from a system and thus the time of
cooling or heating, as well as the variation of temperature, is the subject of
heat transfer.

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 Heat (and Mass) Transfer and
Thermodynamics
❑Reversible versus Irreversible processes
❑ Heat transfer through infinitesimal temperature difference is reversible
❑ Need high k material

❑ ……

❑Whenever heat conducts in a solid, quality of thermal energy is gradually

lowered due to decrease in the temperature at which thermal energy is
available
❑ Need to minimize intermediate heat transfer processes

❑Even to accomplish a simple thermodynamic process with no heat transfer

(adiabatic), you need the knowledge of heat transfer to make the ideal
insulation

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