Principles ofHeat Transfer

Abstract

9R58. Principles of Heat Transfer. - M Kaviany (Dept of Mech Eng, Univ of Michigan, Ann Arbor MI). Wiley, New York. 2002. 973 pp. CD-ROM included. ISBN 0-471-43463-9. $125.00.Reviewed by AM Kanury (Dept of Mech Eng, Oregon State Univ, Corvallis OR 97331-6001).The author states that this book serves as text “for a semester-long course,” that “readers would acquire a fundamental understanding of heat transfer,” and that “at the end of the course the students will have learned some of the specifics of thermal engineering design and analysis and will also be able to articulate innovative use of heat transfer in engineering problems.” Not indicated, however, is whether it is intended as a text for a first course in heat transfer for undergraduate students or for an intermediate or advanced graduate class. For the purpose of preparing this review, one may assume that the book has been written to serve as text for a one-semester introductory course in engineering heat transfer. It can also be reviewed for its suitability as a text for a graduate course or as reference for an advanced study. The book comes with a CD containing a solver for a variety of heat transfer problems. Most of the example problems solved on this CD use the notion of the thermal circuits analog. The output of a session with the solver can be saved in the form of either a table or a graph. The CD also gives a number of models embodied in the major equations in the text. Some examples are resistance models for steady conduction in various geometries; formulas for the Nusselt number as dependent on the Reynolds and Prandtl numbers for convective flows over surfaces and through pipes; and thermal radiation heat exchange between surfaces. In each model, the equation is exhibited, and the required properties are prompted to be entered. Once this is done, calculation occurs quickly and the result indicated. Learning of any new programing techniques does not seem to be necessary in order to use the CD. Numerous example problems are contained in the book as well. So are many end-of-the-chapter homework problems. That “the homework problems are generally not very similar to the example problems” is indeed refreshing. The homework problems are stated in considerable detail and often with figures. A Solutions Manual is said to be available for qualified instructors. The examples as well as the homework problems are tagged to identify the intended purpose of the particular problem. The tags FUN, FAM, or DES respectively represent that the problem deals with a fundamental principle, seeks to develop familiarity with a technique, or addresses a design topic. Sometimes a tag S also appears to imply that the problems call for the use of the equation solver on the CD. Initially, these tags are rather annoying, enough so to force this reader to go back to the Preface. Not many students are known to read Prefaces and Appendices of their textbooks! As an introductory heat transfer text, the present book will have to compete with the books (or revisions) by Arpaci/Kao/Selamet, Mills, Incropera/DeWitt, Holman, and others. The present tome, however, is quite comprehensive in its coverage. Its scope is breathtakingly broad. Its detail is daunting, and its approach is demanding. These characteristics place it in a different class of books, a class not suitable for the market of introductory heat transfer texts. Having said this, it may well be that the broad panoramas this book offers of the entire field and also of the individual problems make it suitable as an excellent text for intermediate and graduate heat transfer courses. In this case, there are only one or two known competing books. Only one or two, because most of the available and proven advanced-level books are not on the entire field of heat transfer, but rather on the three mechanistic components, namely conduction, convection, and radiation. There are four appendices in this book: Some Thermodynamic Relations (6 pp); Derivation of Differential-Volume Energy Equation (12 pp); Tables of Thermochemical and Thermophysical Properties (56 pp); and SO1ver for Principles of Heat Transfer (2 pp). Since the book contains throughout its body so much detail in almost every considered topic, the need for the first two appendices is not evident. Why can they not be integrated into the text at appropriate locations? In addition to the appendices, there is Nomenclature (6 pp); Glossary of Terms (8 pp); List of Key Charts, Figures, and Tables (5 pp); a 7-page subject index; but no author index. Added to 21 pages of the front matter, these supporting materials thus occupy 124 pages, fully an eighth of the book’s total 995 pages. To observe that the book is bulky is rather superfluous. As indicated in Table 1, it is composed of eight chapters. Chapters 3, 4, 6, and 7, respectively, deal with the familiar topics of conduction, thermal radiation, convection due to flows over submerged solid surfaces, and convection in pipe flows. (The author gives to the last two topics the titles Convection: Semibounded fluid streams and Convection: Bounded fluid streams, respectively. The need for this new terminology is not clear to this reviewer.) The material in these four chapters is the usually expected stuff, but the presentation method is different both in form and detail. Throughout the book, thermal circuit models are used. Central to the detail is the tracking of the vector of heat flux due to conduction, convection and radiation through media, and interfaces between media. Interspersed throughout the book are problems dealing with devices based on heat transfer. Examples and problems abound concerning many interesting and unusual topics, but with practical relevance. To mention a few of these topics cooling of: a metal-cutting tool, nuclear reactors and components, small objects such as the components in modern electronic boxes, blood in an external heat exchanger in a cardiopulmonary bypass during an open-heart surgery, etc. It is wonderful to see a quantitative description of the tongue of gray whale as a counter flow exchanger of heat from the warm blood to the cold sea water. Displayed in Chapter 1 is the vast natural and man-made setting in which energy transfer as heat is ubiquitous. Figure 1.12, which also appears on the cover of the book, contains “principles of heat transfer analysis covered in the text and the iconic and thermal circuit presentations of heat transfer.” Throughout the book, in addition to the usual figures and tables, there are charts. Each of almost all figures and charts in this book is loaded with information most of which never gets even a passing mention in the text. Often, this overflowing and abundant information in these visuals is many times more than can possibly be taken in by a reasonably well-prepared and motivated reader. Chart 1.5 at the end of Chapter 1 gives a division of the book into its chapters as well as a list of the major contents of each chapter. This chart would have been more useful if given at the very outset of the book. Chapter 2 adopts the integro-differential energy equation deduced in Section 1.6: to describe the heat flux vector; to write the first law for volumes and surfaces in terms of differential, integral and mixed scales; and to develop different sorts of boundary conditions. Nodal energy balances are developed at the end of this chapter, apparently to set stage for thermal circuit analyses. Such an early appearance of the concept of nodes and nodal balance seems to have another, even more important, use—namely that of setting stage for discretized energy equation for use in numerical analyses. Also presented in Chapter 2 at considerable length are various energy conversion mechanisms. However briefly and uncritically, quantitative relations are given for conversion not only of chemical energy into thermal form through combustion reactions, but also of nuclear energy to thermal form due to fission, fusion, and radioactive decay. Given in Table 2.1 (which repeats itself in Appendix C), are quantitative formulas to calculate the volumetric thermal energy source strength for no less than 16 different conversion mechanisms. Some may consider this overkill; others may appreciate to find here everything anybody doing heat transfer ever might need to know, but is afraid to ask. This reviewer is not sure that a novice student will survive through the absorption of all the information contained in the first two chapters of this text; leave alone the rest. Chapter 5, titled Convection: Unbounded fluid streams, deals with one-dimensional conductive convective heat transfer in porous media and in media within which volumetric heat sources exist. Developed here is the notion of the Peclet number, the magnitude of which is a measure of convection relative to conduction. Seepage of a liquid through a porous wall, evaporation of the liquid at the surface to cool the gas stream, heating of gas streams due to combustion and due to thermal radiation taken into account as a volumetric heat source, etc, are among the topics presented in this chapter. In the guide to instructors and students, it has been said that this chapter can be “omitted without loss of continuity” in a typical one-semester course. Chapter 8 deals with thermal systems. In a more familiar language, it deals with thermal design. The thermal characteristics of various media and their boundaries are diligently depicted in a figure and three charts which are very detailed, as are many others in the book. The nodal energy balance and associated electrical analog are discussed again, including account for storage, conversion, and interaction with the surrounding neighbor nodes. In the third section, which is the heart of this chapter, five design example problems are worked out. The topics of these problems are a heat pipe; thermal inkjet, a MEMS actuator, a thermal regenerator for direct thermoelectric energy conversion, and a porous foam regenerator for a reciprocating combustion engine. These are very exciting topics, for sure! The author does an admirable job writing five or six pages on each topic. Nevertheless, this reviewer is overtaken by a lingering fear of the horrendous detail the author tends to give on these and most of the other topics. Chart 1.5 serves as a guide for the entire book. Charts 1.1, 2.1, 3.1, 5.3, 6.4, and 7.4 present guides for the respective chapters. This idea of guides is useful, but its execution seems to be neither uniform in structure nor consistent in clarity. Chapters 4 and 8 lack the guide charts. Chart 5.1, however, elucidates the definition of degree of boundedness of fluid streams as appearing in the titles of Chapters 5–7. It is hoped that this review is fair to the author while, at the same time, useful to the reader. Principles of Heat Transfer has been a difficult book to review. The author’s competence, creativity, and enthusiasm are contagious. The reader is exhilarated and, in time, exhausted. Its uniquely detailed and unified (through thermal resistance analog and heat flux vector idea) treatment of the vast field of heat transfer makes this book an excellent reference book. However, the degree of detail and the high density of information packed in the figures and charts make it not suitable as a text for introductory or intermediate heat transfer courses. It may serve satisfactorily as text for a graduate course. However, most of the graduate courses in the United States deal with the heat transfer mechanisms of conduction, convection, and thermal radiation in separate courses. Having said all this, this reviewer will surely keep a copy of this book on his bookshelf. He will also strongly recommend it to his university librarian to acquire.