PREFACE

Heat Transfer Professional Version was developed for practicing engineers as well as engineering students enrolled in introductory and follow-up heat-transfer courses that provide more extensive and practical treatment of convection heat transfer. The book should also serve as a useful reference for graduate students and others interested in the discipline of heat transfer.

The book features (1) the thorough presentation of fundamental concepts in the context of classic one-dimensional applications; (2) the analysis of multidimensional conduction-heat-transfer processes, with special consideration given to a practical approximate thermal circuit method and to the modern numerical finite-difference method; (3) the analysis of radiation heat transfer; and (4) the analysis of convection heat transfer. Although a basic knowledge of ordinary differential equations, partial derivatives, and elementary thermodynamics and fluid mechanics is generally necessary for a proper understanding of the material, these subjects are reviewed as they are needed.

The presentation throughout the text generally involves the use of brief developments followed by practical examples. Fundamental concepts pertaining to the mechanisms of heat transfer are introduced in Chap. 1. One-dimensional analyses are developed in Chap. 2, with emphasis given to the importance of limiting criteria for common systems, such as composite walls and fins, that are inherently multidimensional. Approaches for solving multidimensional conduction problems are considered in Chap. 3, with attention focused on the simple but accurate numerical finite-difference method in Chap. 4. Fundamentals of thermal radiation and the practical analysis of radiation heat transfer, which involves the use of the thermal network concept, are presented in Chap. 5. The topic of convection heat transfer is introduced in Chap. 6, with the theory of convection presented in Chap. 7. The practical analysis approach, which involves the use of modern convection correlations, is developed in Chaps. 8 through 11 for forced and natural convection, boiling and condensation, and heat exchangers, with attention given to both hydraulic and thermal aspects. Concerning the treatment of convection heat transfer, the format is such that the practical approach of Chaps. 8 through 11 can be studied before or after (or independent of) the material in Chap. 7, which deals with the theory of convection.

The unique approach to the study of convection heat transfer developed in this book, which separates the theory of convection (Chap. 7) and the practical analysis approach (Chaps. 8-11), has been motivated by the fact that engineers and engineering students often encounter difficulties in dealing with this important topic. The traditional approach involves the presentation of the theory of convection, which is fairly complex and sometimes appears somewhat bewildering, interspersed with practical aspects. Topics generally covered in the theory of convection include (1) formulation of the boundary-layer equations (partial differential) for laminar and turbulent flows, (2) formulation of related integral equations, (3) introduction of the similarity-solution approach for laminar forced and natural convection external boundary-layer flows, (4) development of approximate integral solutions for laminar and turbulent external boundary-layer flows, and more. These topics are important, but are not essential to the development of the practical analysis approach used in heat-exchanger analysis and in the solution of most basic convection-heat-transfer problems that engineers encounter in practice. The presentation of the practical analysis approach in a self-contained unit enables beginning students to gain a basic understanding of the key elements of the evaluation and design of convection systems, with or without the study of details of the theory of convection, and provides practicing engineers with an effective format for efficient review of practical or theoretical aspects of particular interest.

In this connection, the practical hydraulic- and thermal-analysis approach to analyzing heat exchangers and other internal-flow processes involves the use of bulk-stream characteristics. This perspective has traditionally been developed in the context of a defining equation for bulk-stream (or mixing-cup) temperature. Unfortunately, this critical issue is frequently blurred by imprecise mathematical formulations. The approach taken in Chaps. 6 through 11 in this text features a less restrictive fundamental formulation that involves the useful concept of bulk-stream-enthalpy rate. The basic relationships among mass-flow rate, enthalpy rate, distributions in velocity u and temperature T, and the thermophysical properties used to develop this more general perspective are introduced in Chap. 6 and Appendixes L and M. In addition to providing a basis for the development of a clearer and more general practical hydraulic- and thermal-analysis approach, the concept of enthalpy rate and momentum rate is used in Chap. 7 and Appendix I to develop what is believed to be a simpler less tedious approach to the formulation of the differential and integral equations for boundary-layer flow. Because of its versatility and relative simplicity, the approximate integral-solution approach is featured in Chap. 7 for external flows.

Relative to standard undergraduate heat-transfer textbooks that are presently available, Heat Transfer&mdash Professional Version provides approximately 75% additional coverage of the topic of convection heat transfer. This extended coverage includes practical aspects such as (1) adaptation of the practical thermal-analysis approach to variable-property flow and flow over finned surfaces in Chap. 8; (2) development of comprehensive thermal/hydraulic analyses of heat exchangers that involves the evaluation of convection coefficients for shell-and-tube exchangers as well as for double-pipe, crossflow, and plate exchangers in Chap. (11); (3) introduction of a practical numerical method for analyzing convection processes associated with flow in heat-exchanger cores in Chaps. 8 and 11 and Appendix P; (4) development of bulk-stream relations for variable-property flow in Appendix L; (5) development of practical hydraulic-analysis relations for flow in heat-exchanger cores in Appendix M; (6) presentation of practical heat-exchanger-solution relations and characteristics in Appendixes N and O; and (7) introduction of heat-exchanger uncertainty analysis in Appendix R. In addition, theoretical aspects are covered that include (1) expanded treatment of the integral-solution method for laminar thermal-boundary-layer flow in Chap. 7; (2) introduction to classical approaches to modeling turbulence in Chap. 7; (3) development of theoretical solutions for basic turbulent boundary-layer flows in Chap. 7; (4) development of boundary-layer equations for laminar flow in Appendix I; and (5) development of a two-parameter integral method for laminar natural convection in Appendix K.

To further aid the reader in understanding the heat-transfer literature, the numerical finite-element method for solving heat-transfer problems is introduced in Appendix F.

Because the changeover to metric units continues in many countries, both the international system of units (SI) and the engineering system are used, with the SI system being used in the body of the text and in approximately 85% of the examples.

With regard to the examples, a consistent methodology is employed that features the following format:

EXAMPLE (Statement of problem to be solved.)
Solution
Objective (Concise statement of what is to be done.)
Schematic (Sketch of system showing all knows and basic conditions.)
Assumptions/Conditions
Properties (Listing of pertinent thermophysical properties.)
Analysis (Mathematical formulation/solution, calculations, comments.)

It is believed that this systematic approach will aid the reader in recognizing and understanding the specific concepts presented in each example.

To enhance the usefulness of Heat Transfer- Professional Version as a self-study guide and problem-solving resource for practicing engineers and students, a computer program has been developed exclusively for the book by Dr. Wen Wu and Dr. Edward Lumsdaine.

The Heat Transfer Software is easy to use and requires no manual; comprehensive, treating all basic topics covered in the book; coordinated with book by chapter/section numbers that correspond to each topic; integrated with the book by the use of examples as topic cases and by indicating equation numbers that provide the basis for solutions developed by the software; and adaptable, such that the parameters for each topic can be modified according to the dictates of the problem under consideration.

Heat Transfer—Professional Version book and software has been developed with the hope that these materials will contribute to the effective study and practice of engineering-heat transfer.