3R51. Dynamics of Regenerative Heat Transfer. Series in Computational and Physical Processes in Mechanics and Thermal Sciences. - AJ Willmott (Dept of Comput Sci, Univ of York, UK). Taylor & Francis Publ, New York NY. 2002. 298 pp. ISBN 1-56032-369-8. $99.00.

Reviewed by H Perez-Blanco (Dept of Mech Eng, Penn State, 338 Reber Bldg, University Park PA 16801).

This book offers an insightful blend between theory and practice in an area where the deficiency of steady-state treatments is apparent. The text has an engaging style; a rigorous, but clearly explained mathematical treatment; and an organization that develops the reader from the fundamentals to the most intricate aspects of dynamic response of regenerators. In this way, the book accomplishes two simultaneous objectives: enabling the calculation of conventional or novel regenerators and furnishing useful procedures for practical applications.

The material is divided into ten chapters. The introductory Chapter 1 is followed by the simplest problem, called the single-blow problem, addressed in a comprehensive form in Chapters 2 and 3. The initial conditions of the single-blow problem are restrictive from a practical view point, and the more complete case and variations are introduced in Chapters 4–8.

Chapter 4 has a practical bent, presenting both a rigorous mathematical model based on cyclic operation and actual regenerator configurations. Chapter 5 introduces methods for solution of the models presented in Chapter 4, introducing nonlinearities in the models. Chapter 6 is a labor-saving chapter, in that starting from basic principles, heat transfer coefficients can be readily estimated via normalization of the Fourier equation. Integral equation methods are covered in Chapter 7, with the caveat that, at present, they cannot cover nonlinear models, with variable gas or solid properties for instance.

Most vexing problems, namely those associated with nonlinear problems are addressed in Chapter 8. Here, nonlinearities arise from inhomogeneous properties, construction, or operational strategies. A general numerical approach to these unique problems is presented along with a number of well-developed examples. The practitioner will find here approaches to include radiative heat transfer effects as well. In many ways, this particular chapter alone may justify the purchase of this book. Chapter 9 focuses on transient regenerator performance. The topics here are somewhat refractory to analysis because the characterization of transients throughout a variety of applications is elusive at best. Yet, a general method of attack based on a matrix method is presented as a starting point. The approach of this chapter could be invaluable to those involved in the growing area of risk analysis. Parallel-flow regenerators are briefly addressed in Chapter 10, where closed-form and numerical solutions (somewhat simpler than those for counterflow) are presented. A performance comparison between parallel and counterflow regenerators closes the chapter.

Whereas regenerators have often been used in the steel and glass industries, the advent of heat recovery technology for environmental control purposes, especially gas-activated dehumidifying equipment has resulted in new applications for the techniques that this book so aptly describes. Perhaps in the future, the author will include simultaneous heat and mass transfer treatments for enthalpy wheels. We attempted to convey via this review that Dynamics of Regenerative Heat Transfer, offers the most insightful blend of mathematical rigor oriented towards practical applications. The former is a necessary condition for accurate and consistent design; the latter is a necessary condition for relevance to the engineering endeavor. It is a reasonable expectation that those involved at all levels (ie, from researchers to practitioners) in heat recovery technology, and those with an interest in transient regimes of thermal technology, will find this book extremely useful for their work.