9R47. Extended Surface Heat Transfer. - AD Kraus (Dept of Mech Eng, Univ of Akron, Akron OH), A Aziz (Dept of Mech Eng, Gonzaga Univ, Spokane WA), and J Welty (Dept of Mech Eng, Oregon State Univ, Corvallis OR). Wiley, New York. 2001. 1105 pp. ISBN 0-471-39550-1. $175.00.
Reviewed by DP Sekulic (Col of Eng, Univ of Kentucky, 425 CRMS Bldg, Lexington KY 40506-0108).
This book undoubtedly represents a most thorough compilation of the knowledge related to design and performance of fins and finned surfaces for heat transfer applications. In addition, a very detailed review of the work devoted to various aspects of extended surface convective heat transfer is provided. For those familiar with the first edition of Extended Surface Heat Transfer, by Donald Q Kern and Allan D Krauss (1972), the most striking difference, as indicated by the authors of this new edition, is a substantially increased volume of the work done in the field over the last 30 years.
This book should be considered neither as a textbook nor as a monograph focused on a single topic. It rather represents an almost encyclopedic effort of the authors to collect a variety of information about the subject and present this in a user-friendly manner. The authors were not reluctant to include a number of examples to demonstrate the use of various concepts, procedures, and calculation routines. Moreover, the approach to mathematical modeling and corresponding solution findings is very transparent and may assist a reader in developing the skills needed to analyze similar problems. Hence, the book may be recommended not only to the engineers who in their daily practice have to deal with an extended surface design, but also to students at senior and post graduate levels who are familiar with basic heat transfer concepts and are capable of using advanced applied mathematics tools.
The book consists of 20 chapters, which may be conveniently split into two groups. The first set of chapters (Chs 1–3, 5–9, and 13–17) is devoted to steady-state and transient conduction-convection-radiation studies of 2D and some 3D fin configurations and fined surfaces, while the second set of chapters (Chs 4, 10–12, and 18–20) provides information about convective heat transfer characteristics (notably heat transfer coefficients) associated with finned surfaces for single-phase and two-phase conditions, including presentation of extended surface heat exchangers design topics. Clearly, the main contribution of this book is located in the first set of chapters. In the existing literature, there are some more elaborate and very detailed reference sources devoted to determination of heat transfer coefficients in single- and two-phase flows. Also, design of heat exchangers has been a topic of a number of specialized sources devoted to heat exchangers. However, as a guide to designs of fins, finned surfaces, and/or finned array assemblies and their analysis, this book should be considered as a premier source.
Chapter 1, Convection with simplified constraints, introduces the basic concept of fin efficiency and treats basic configurations such as longitudinal fins, radial fins and spines assuming the validity of the traditional Murray-Gardner idealizations. This material is extended in Chapter 2, entitled Convection with real constraints, following an effort to relax some of the Murray-Gardner idealizations related to geometry, boundary conditions, and presence of internal thermal energy generation. Chapter 3, Convective optimizations, considers optimizations of individual fins of rectangular, trapezoidal, triangular, concave parabolic, convex parabolic, and hyperbolic profiles. Chapter 4, Convection coefficients, provides a rather basic compilation of information related to heat transfer coefficient determination. The very detailed closure of this chapter provides a balance to this limited set of information through an extensive literature review. Chapters 5 through 8, ie, Linear transformations, Elements of linear transformations, Algorithms for finned array assembly, and Advanced Array methods and array optimization, are devoted to linear transformations for fins and finned array assemblies and some advanced methods for arrays with loops. Based on the argument that the fin efficiency definition does not use a uniform standard for comparing different fins (ie, “two fins of different dimensions in the same environment may have the same efficiency but they may transmit different quantities of heat”), an alternative approach (developed over the years by the first author) has been suggested in particular for finned arrays. This approach is based on the realization that there is a linear transformation that leads to mapping of the conditions from the fin base to conditions at the fin tip and vice versa. This approach introduces instead of fin efficiency the so-called thermal transmission ratio (ie, the input admittance).
Chapter 9, Finned passages, is devoted to the application of methods for evaluation of the input admittance and fin efficiency of single, double, triple, and quadruple stacks of compact heat transfer cores for different conditions of heat loading. The following three chapters (Chs 10–12) provide information about traditional design methods for Compact heat exchangers, Longitudinal fin double-pipe exchangers, and Transverse high-fin exchangers (ie, air-fin coolers), respectively. Both the effectiveness-number of transfer units and logarithmic mean temperature difference methods were used. Chapter 13, Fins with radiation, explores the analysis and design of fins with thermal radiation as the sole heat transfer mode, while Chapter 14, Optimum design of radiating and convective-radiating fins, deals with optimum dimensions of the fins exposed to both types of conditions. Chapters 15 through 17 are adding new dimensions to the study of various fin configurations, ie, focused on additional spatial and temporal dependences. Chapter 15 is devoted to “Multidimensional heat transfer in fins and fin assemblies, Chapter 16 presents the intricacies of Transient heat transfer in extended surfaces, and Chapter 17 deals with Periodic heat flows in fins. Phase change phenomena associated with extended surfaces is summarized in Chapters 18 and 19, ie, Boiling from finned surfaces and Condensation on finned surfaces. The book concludes with Chapter 20, Augmentation and additional studies, that addresses a variety of issues related to heat transfer augmentation and performance characteristic of some compact heat transfer surfaces, including heat transfer in electronic equipment, heat pipes, solar collectors, and finned regenerators.
For the convenience of the reader, the book is equipped with fairly detailed author and subject indexes. Nomenclatures are listed for each chapter separately, which may be the only plausible solution in a book covering such a vast number of sources. Two detailed appendices, one devoted to gamma and Bessel functions and the other to matrices and determinants, are helpful summaries for those less familiar with the mathematical background information needed to follow the material exposition. The list of references takes more than three-dozen pages and should be considered as the most comprehensive on the subject.
In conclusion, it should be pointed out that in spite of a relatively high price, Extended Surface Heat Transfer should find its place in a library of a specialist dealing with extended surface heat transfer, and is a must for libraries supporting various thermal design fields.