11R54. Microgravity Combustion: Fire in Free Fall. - Edited by HD Ross (NASA Glenn Res Center, Cleveland OH). Academic Press, San Diego. 2001. 575 pp. ISBN 0-12-598190-2. $124.95.
Reviewed by SR Gollahalli (Lesch Centennial Chair, Director, Sch of Aerospace and Mech Eng, Univ of Oklahoma, Norman OK 73019-0601).
This book is a compilation of eight chapters contributed by 16 authors, who have done extensive research on various combustion issues in normal and microgravity environments. This reviewer also had the privilege of reviewing the first book on Microgravity Combustion, Combustion Experiments in Zero Gravity Laboratory, edited by Thomas Cochran (AIAA Progress in Aeronautics and Astronautics, Vol. 73, 1981), for AMR (Vol. 35, No. 4, p B586, 1982). During the last two decades, substantial advances have occurred in microgravity testing facilities, diagnostics, and computational capabilities. They have enabled several researchers in USA and abroad to conduct in depth studies on the effects of buoyancy on various scientific phenomena in the fields of physics, fluid mechanics, materials, bioengineering, and combustion. This book is a survey and review of the progress on the effects of gravity through 1999 on several combustion phenomena.
Although, according to the editor, no requirements on organization or content were imposed on authors, it is nice to see most of the chapters follow a somewhat similar and consistent format. They begin with a list of nomenclature, a short abstract, a brief introduction to the topic covered, a detailed review of the research studies on the topic, concluding remarks, and an extensive list of references. Although the title of the book suggests that the material deals with only microgravity combustion, most of the authors have covered the same combustion phenomena in normal gravity to provide baseline information for comparison with microgravity phenomena. Thus, even the readers that are new to a combustion topic, but interested in normal gravity as well as microgravity effects, find the book useful. Of course, as expected, the authors have drawn much of the material from their own research even though they discuss it in the light of other studies in the literature.
The first chapter, written by the editor Howard Ross, presents an overview of the fundamentals of the gravity effects, issues of scaling buoyancy effects, experimental methods available for minimizing gravity influence, and an example of candle flame characteristics affected by gravity. The second chapter on premixed flames by Paul Rooney begins with a discussion of the salient time scales significant in microgravity combustion and deals with buoyancy effects on flammability limits, flame instabilities, stretched and curved flames, cool flames, and turbulent flames. This author also presents a list of topics recommended for future research. Gerard Faeth’s third chapter covers laminar and turbulent diffusion flames, limiting the presentation to only gas flames. After briefly discussing the significance of non-dimensional numbers relevant to quantify the effects of gravity, the author discusses microgravity combustion experimental facilities and presents extensive experimental data on the flame shapes, flame structure measurements and predictions, and soot processes. The second half of this chapter is devoted to turbulent diffusion flames, including laminar flamelet concepts, flame vortex interactions, and transition to turbulence.
Microgravity droplet combustion is the topic of the fourth chapter by Mun Young Choi and Frederick Dryer. After an introduction to the literature on low gravity studies including the classical experiments of Kumagai, the authors present classical theories of droplet combustion, recent advances in theoretical analysis, experimental methods for microgravity studies, and extensive experimental and numerical results on n-heptane, methanol, and multicomponent droplet combustion including its disruptive behavior. This chapter also covers other pertinent topics such as droplet arrays, pressure effects, and convective combustion effects. The fifth chapter, by James Tien and his coauthors, is devoted to flame spread and smolder wave propagation and includes a section on the overview of flame spread over solid surfaces, relevant time scales, theoretical models of flame spread over thin solids, ignition of solids in opposed and concurrent flows, flame spread over liquid pools, and smoldering wave propagation. Richard Yetter and Frederick Dryer discuss the classification and regimes of metal particle combustion with a focus on microgravity research studies in Chapter 6 and conclude it with recommendations for future studies. Chapter 7, by Richard Axelbaum and John Moore, deals with combustion applications for material synthesis. Condensed-phase combustion, self-propagating high-temperature combustion, the gas-phase combustion synthesis processes, and the important reaction parameters that govern them are discussed. The applications of these processes and influence of gravity for the production of powders, fullerenes, and nanotubes are covered. Robert Friedman and Howard Ross present the applications of combustion technology to fire safety issues in human-crew space missions including lunar and Martian missions.
The book’s editing, printing, and quality of illustrations are impressive. The cover design showing the candle flame is an appropriate reflection of the contents of the book. The table of contents and subject index are organized well. This book contains not only the basic material required for a beginning researcher in microgravity combustion, but also includes a valuable collection of recent data and references useful for experienced researchers as well. Microgravity Combustion: Fire in Free Fall is recommended as a valuable reference source for research libraries and higher educational institutions.