1R42. Science and Engineering of Droplets: Fundamentals and Applications. - Huimin Liu (Prod and Dev Div, Citation Corp, Southfield MI). Noyes Publ, Park Ridge NJ. Distributed in USA by William Andrew Publ, Norwich NY. 2000. 527 pp. ISBN 0-8155-1436-0. $139.00.

Reviewed by MC Altan (Sch of Aerospace and Mech Eng, Univ of Oklahoma, 865 Asp Ave, Room 212, Norman OK 73019).

This book contains a detailed review of applications and fundamentals of droplet processes. It systematically presents a wide variety of practical as well as theoretical issues in processes involving drop formation. It is well written and logically structured, even for a casual reader. In the first two chapters, it presents different processes and techniques for droplet generation. It addresses the scientific fundamentals, analytical correlations, and microscale analysis of droplets in the subsequent chapters. It is comprised of six chapters and contains a total of 715 references and a comprehensive 18-page index.

Chapter 1, General Introduction, briefly describes the science and engineering applications of droplets. It also introduces various methods of droplet generation and the size scales of droplets. The author classifies the droplets into two primary types: droplets of normal liquids and droplets of melts, and uses this classification to structure the rest of the manuscript.

Chapter 2, Processes and Techniques for Droplet Generation, describes various methods of atomization. It is comprised of two main sections: Atomization of Normal Liquids and Atomization of Melts. It does not address scientific fundamentals or mathematical modeling and analysis. Instead it focuses on the application details and practical issues such as the advantages and limitations of different atomization methods. Chapter 2 also contains useful tables of the thermophysical properties of gases, metals, and alloys that are commonly used in atomization processes.

Chapter 3, Fundamental Phenomena and Principles in Droplet Processes, reviews the dynamics of droplet generation and deformation. It starts with the review of droplet formation in atomization of normal liquids. Different modes of droplet formation, such as dripping, and column, jet, ligament, sheet, and free- surface breakup are described. Criteria for the break up of various types of liquid streams and equations for the resulting drop diameters are complied and presented. The details of the governing equations and the mathematical derivations are not included, yet a comprehensive list of references is included for those who seek additional information. A significant part of this chapter is devoted to droplet formation in atomization of melts, which is affected by the non-isothermal nature of the process. Splashing, spreading, and evaporation of droplets on a solid surface are also discussed.

Chapter 4, Empirical and Analytical Correlations of Droplet Properties, reviews the properties such as the droplet size distribution and deformation generated by different atomization processes. The first part of this chapter presents the mathematics of distribution functions used to analyze various properties of the droplets. It then gives the correlation equations for the droplet sizes of normal liquids and melts. The last part of the chapter discusses deformation of droplets impinging on a solid surface. Correlation equations are given for the final splat diameter of an impinging drop.

Chapter 5, Theoretical Calculations and Numerical Modeling of Droplet Processes, describes the basic theory and modeling of droplet formation and breakup. It mainly discusses and compiles results published in the literature without going into complexities of the mathematics involved in theoretical and computational modeling.

Chapter 6, Measurement Techniques for Droplet Properties and Intelligent Control of Droplet Processes, presents various methods for measuring droplet size, velocity, number density, temperature, and deformation on a surface. The section on intelligent control is very brief with less than five pages.

The quality of most of the charts and pictures is good. However, the quality of a few figures that are reproduced from older articles is marginal. Some of the legends and axes labels are too small for comfortable reading. The strength of this book is in its excellent review and compilation of the vast literature on the fundamentals and practical applications of droplet generation, deformation, and processing.

In summary, Science and Engineering of Droplets: Fundamentals and Applications is comprehensive enough to be a useful resource for application engineers and scientific researchers. It is a valuable contribution to the literature, and this reviewer strongly recommends it to researchers and libraries as a reference book on droplets.