Preface
This text has evolved from a need for a single volume that embraces a wide range of topics in fluid mechanics. The material consists of two parts—four chapters on macroscopic or relatively large-scale phenomena, followed by ten chapters on microscopic or relatively small-scale phenomena. Throughout, I have tried to keep in mind topics of industrial importance to the chemical engineer. The scheme is summarized in the following list of chapters.
Part I—Macroscopic Fluid Mechanics
1. Introduction to Fluid Mechanics
2. Mass, Energy, and Momentum Balances
4. Flow in Chemical Engineering Equipment
Part II—Microscopic Fluid Mechanics
5. Differential Equations of Fluid Mechanics
6. Solution of Viscous-Flow Problems
7. Laplace’s Equation, Irrotational and Porous-Media Flows
8. Boundary-Layer and Other Nearly Unidirectional Flows
10. Bubble Motion, Two-Phase Flow, and Fluidization
12. Microfluidics and Electrokinetic Flow Effects
13. An Introduction to Computational Fluid Dynamics and FlowLab
14. COMSOL (FEMLAB) Multiphysics for Solving Fluid Mechanics Problems
In our experience, an undergraduate fluid mechanics course can be based on Part I plus selected parts of Part II, and a graduate course can be based on much of Part II, supplemented perhaps by additional material on topics such as approximate methods and stability.
Second edition. I have attempted to bring the book up to date by the major addition of Chapters 12, 13, and 14—one on microfluidics and two on CFD (computational fluid dynamics). The choice of software for the CFD presented a difficulty; for various reasons, I selected FlowLab and COMSOL Multiphysics, but there was no intention of “promoting” these in favor of other excellent CFD programs.1 The use of CFD examples in the classroom really makes the subject come “alive,” because the previous restrictive necessities of “nice” geometries and constant physical properties, etc., can now be lifted. Chapter 9, on turbulence, has also been extensively rewritten; here again, CFD allows us to venture beyond the usual flow in a pipe or between parallel plates and to investigate further practical situations such as turbulent mixing and recirculating flows.
1 The software name “FEMLAB” was changed to “COMSOL Multiphysics” in September 2005, the first release under the new name being COMSOL 3.2.
Example problems. There is an average of about six completely worked examples in each chapter, including several involving COMSOL (dispersed throughout Part II) and FlowLab (all in Chapter 13). The end of each example is marked by a small, hollow square: 
. All the COMSOL examples have been run on a Macintosh G4 computer using FEMLAB 3.1, but have also been checked on a PC; those using a PC or other releases of COMSOL/FEMLAB may encounter slightly different windows than those reproduced here. The format for each COMSOL example is: (a) problem statement, (b) details of COMSOL implementation, and (c) results and discussion (however, item (b) can easily be skipped for those interested only in the results).
The numerous end-of-chapter problems have been classified roughly as easy (E), moderate (M), or difficult/lengthy (D). The University of Cambridge has given permission—kindly endorsed by Professor J.F. Davidson, F.R.S.—for several of their chemical engineering examination problems to be reproduced in original or modified form, and these have been given the additional designation of “(C)”.
Acknowledgments. I gratefully acknowledge the written contributions of my former Michigan colleague Stacy Birmingham (non-Newtonian fluids), Brian Kirby of Cornell University (microfluidics), and Chi-Yang Cheng of Fluent, Inc. (FlowLab). Although I wrote most of the COMSOL examples, I have had great help and cooperation from COMSOL Inc. and the following personnel in particular—Philip Byrne, Bjorn Sjodin, Ed Fontes, Peter Georen, Olof Hernell, Johan Linde, and Rémi Magnard. At Fluent, Inc., Shane Moeykens was instrumental in identifying Chi-Yang Cheng as the person best suited to write the FlowLab chapter. Courtney Esposito and Jordan Schmidt of The MathWorks kindly helped me with MATLAB, needed for the earlier 2.3 version of FEMLAB.
I appreciate the assistance of several other friends and colleagues, including Nitin Anturkar, Stuart Churchill, John Ellis, Kevin Ellwood, Scott Fogler, Leenaporn Jongpaiboonkit, Lisa Keyser, Kartic Khilar, Ronald Larson, Susan Montgomery, Donald Nicklin, the late Margaret Sansom, Michael Solomon, Sandra Swisher, Rasin Tek, Robert Ziff, and my wife Mary Ann Gibson Wilkes. Also very helpful were Bernard Goodwin, Elizabeth Ryan, and Michelle Housley at Prentice Hall PTR, and my many students and friends at the University of Michigan and Chulalongkorn University in Bangkok. Others are acknowledged in specific literature citations.
Further information. The website http://www.engin.umich.edu/~fmche is maintained as a “bulletin board” for giving additional information about the book—hints for problem solutions, errata, how to contact the authors, etc.—as proves desirable. My own Internet address is [email protected]. The text was composed on a Power Macintosh G4 computer using the TEXtures “typesetting” program. Eleven-point type was used for the majority of the text. Most of the figures were constructed using MacDraw Pro, Excel, and KaleidaGraph.
Professor Terence Fox, to whom this book is dedicated, was a Cambridge engineering graduate who worked from 1933 to 1937 at Imperial Chemical Industries Ltd., Billingham, Yorkshire. Returning to Cambridge, he taught engineering from 1937 to 1946 before being selected to lead the Department of Chemical Engineering at the University of Cambridge during its formative years after the end of World War II. As a scholar and a gentleman, Fox was a shy but exceptionally brilliant person who had great insight into what was important and who quickly brought the department to a preeminent position. He succeeded in combining an industrial perspective with intellectual rigor. Fox relinquished the leadership of the department in 1959, after he had secured a permanent new building for it (carefully designed in part by himself).
T.R.C. Fox
Fox was instrumental in bringing Peter Danckwerts, Kenneth Denbigh, John Davidson, and others into the department. He also accepted me in 1956 as a junior faculty member, and I spent four good years in the Cambridge University Department of Chemical Engineering. Danckwerts subsequently wrote an appreciation2 of Fox’s talents, saying, with almost complete accuracy: “Fox instigated no research and published nothing.” How times have changed—today, unless he were known personally, his résumé would probably be cast aside and he would stand little chance of being hired, let alone of receiving tenure! However, his lectures, meticulously written handouts, enthusiasm, genius, and friendship were a great inspiration to me, and I have much pleasure in acknowledging his positive impact on my career.
James O. Wilkes
August 18, 2005
2 P.V. Danckwerts, “Chemical engineering comes to Cambridge,” The Cambridge Review, pp. 53–55, February 28, 1983.