BACKGROUND
Heat and mass transfer is a basic science that deals with the rate of
transfer of thermal energy. It has a broad application area ranging from
biological systems to common household appliances, residential and
commercial buildings, industrial processes, electronic devices, and food processing.
Students are assumed to have an adequate background in calculus and
physics. The completion of first courses in thermodynamics, fluid mechanics,
and differential equations prior to taking heat transfer is desirable. However,
relevant concepts from these topics are introduced and reviewed as needed. OBJECTIVES
This book is intended for undergraduate engineering students in their sophomore
or junior year, and as a reference book by practicing engineers. The objectives
of this text are
• To cover the basic principles of heat transfer.
• To present a wealth of real-world engineering examples to give students
a feel for how heat transfer is applied in engineering practice.
• To develop an intuitive understanding of heat transfer by emphasizing
the physics and physical arguments.
It is our hope that this book, through its careful explanations of concepts and
its use of numerous practical examples and figures, helps the students develop
the necessary skills to bridge the gap between knowledge and the confidence
for proper application of that knowledge.
In engineering practice, an understanding of the mechanisms of heat transfer is
becoming increasingly important since heat transfer plays a crucial role in the design
of vehicles, power plants, refrigerators, electronic devices, buildings, and
bridges, among other things. Even a chef needs to have an intuitive understanding
of the heat transfer mechanism in order to cook the food “right” by adjusting the
rate of heat transfer. We may not be aware of it, but we already use the principles
of heat transfer when seeking thermal comfort. We insulate our bodies by putting
on heavy coats in winter, and we minimize heat gain by radiation by staying in
shady places in summer. We speed up the cooling of hot food by blowing on it and
keep warm in cold weather by cuddling up and thus minimizing the exposed surface
area. That is, we already use heat transfer whether we realize it or not.GENERAL APPROACH
This text is the outcome of an attempt to have a textbook for a practically
oriented heat transfer course for engineering students. The text covers the
standard topics of heat transfer with an emphasis on physics and real-world
applications. This approach is more in line with students’ intuition, and makes
learning the subject matter enjoyable.
The philosophy that contributed to the overwhelming popularity of the prior
editions of this book has remained unchanged in this edition. Namely, our
goal has been to offer an engineering textbook that
• Communicates directly to the minds of tomorrow’s engineers in a simple
yet precise manner.
• Leads students toward a clear understanding and firm grasp of the basic
principles of heat transfer.
• Encourages creative thinking and development of a deeper understanding
and intuitive feel for heat transfer.
• Is read by students with interest and enthusiasm rather than being used
as an aid to solve problems.
Special effort has been made to appeal to students’ natural curiosity and to
help them explore the various facets of the exciting subject area of heat transfer.
The enthusiastic response we received from the users of prior editions—
from small colleges to large universities all over the world—indicates that our
objectives have largely been achieved. It is our philosophy that the best way to
learn is by practice. Therefore, special effort is made throughout the book to
reinforce material that was presented earlier.
Yesterday’s engineer spent a major portion of his or her time substituting values
into the formulas and obtaining numerical results. However, now formula
manipulations and number crunching are being left mainly to the computers.
Tomorrow’s engineer will have to have a clear understanding and a firm grasp
of the basic principles so that he or she can understand even the most complex
problems, formulate them, and interpret the results. A conscious effort is made
to emphasize these basic principles while also providing students with a perspective
at how computational tools are used in engineering practice. NEW IN THIS EDITION
All the popular features of the previous edition are retained while new ones
are added. With the exception of the coverage of the theoretical foundations of
transient heat conduction and moving the chapter “Cooling of Electronic
Equipment” to the Online Learning Center, the main body of the text remains
largely unchanged. The most significant changes in this edition are highlighted
below.A NEW TITLE
The title of the book is changed to Heat and Mass Transfer: A Practical
Approach to attract attention to the coverage of mass transfer. All topics related
to mass transfer, including mass convection and vapor migration through building
materials, are introduced in one comprehensive chapter (Chapter 14).EXPANDED COVERAGE OF TRANSIENT CONDUCTION
The coverage of Chapter 4, Transient Heat Conduction, is now expanded to include
(1) the derivation of the dimensionless Biot and Fourier numbers by
nondimensionalizing the heat conduction equation and the boundary and initial
conditions, (2) the derivation of the analytical solutions of a one-dimensional
transient conduction equation using the method of separation of variables,
(3) the derivation of the solution of a transient conduction equation in the semiinfinite
medium using a similarity variable, and (4) the solutions of transient
heat conduction in semi-infinite mediums for different boundary conditions
such as specified heat flux and energy pulse at the surface.FUNDAMENTALS OF ENGINEERING (FE) EXAM PROBLEMS
To prepare students for the Fundamentals of Engineering Exam (that is becoming
more important for the outcome-based ABET 2000 criteria) and to facilitate
multiple-choice tests, about 250 multiple-choice problems are included
in the end-of-chapter problem sets. They are placed under the title “Fundamentals
of Engineering (FE) Exam Problems” for easy recognition. These
problems are intended to check the understanding of fundamentals and to help
readers avoid common pitfalls.MICROSCALE HEAT TRANSFER
Recent inventions in micro and nano-scale systems and the development of
micro and nano-scale devices continues to pose new challenges, and the understanding
of the fluid flow and heat transfer at such scales is becoming more
and more important. In Chapter 6, microscale heat transfer is presented as a
Topic of Special Interest.THREE ONLINE APPLICATION CHAPTERS
The application chapter “Cooling of Electronic Equipment” (Chapter 15) is
now moved to the Online Learning Center together with two new chapters
“Heating and Cooling of Buildings” (Chapter 16) and “Refrigeration and
Freezing of Foods” (Chapter 17).CONTENT CHANGES AND REORGANIZATION
With the exception of the changes already mentioned, minor changes are made
in the main body of the text. Nearly 400 new problems are added, and many of
the existing problems are revised. The noteworthy changes in various chapters
are summarized here for those who are familiar with the previous edition.
• The title of Chapter 1 is changed to “Introduction and Basic Concepts.”
Some artwork is replaced by photos, and several review problems on the
first law of thermodynamics are deleted.
• Chapter 4 “Transient Heat Conduction” is revised greatly, as explained
previously, by including the theoretical background and the mathematical
details of the analytical solutions.
• Chapter 6 now has the Topic of Special Interest “Microscale Heat Transfer”
contributed by Dr. Subrata Roy of Kettering University.
• Chapter 8 now has the Topic of Special Interest “Transitional Flow in
Tubes” contributed by Dr. Afshin Ghajar of Oklahoma State University.
• Chapter 13 “Heat Exchangers” is moved up as Chapter 11 to succeed
“Boiling and Condensation” and to precede “Radiation.”
• In the appendices, the values of some physical constants are updated,
and Appendix 3 “Introduction to EES” is moved to the enclosed CD and
the Online Learning Center.
To obtain an instructor login for this Online Learning Center, ask your local sales representative.
If you're an instructor thinking about adopting this textbook, request a free copy for review.
2007 McGraw-Hill Higher Education