Page 20 - Introduction to Computational Fluid Dynamics

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PREFACE
flow or for a reacting flow are being explored through CFD. Newer application areas 0:54 xix
such as heat and mass transfer in biocells are also beginning to be explored through
CFD. Such areas are likely to remain more at the research level than to be part
of regular practice and, therefore, a student, over the next few years at least, may
encounter them in research at a Ph.D. level. It is my belief that the approach adopted
in this book will provide adequate grounding for such pursuits.
Although this is an introductorybook,there are some departuresandbasicnovel-
ties to which it is important to draw the reader’s attention. The first of these concerns
the manner in which the fundamental equations of motion (the Navier–Stokes equa-
tions) are written. Whereas most textbooks derive or write these equations for a
continuum fluid, it is shown in the first chapter of this book that since numerical
solutions are obtained in discretised space, the equations must be written in such a
way that they are applicable to both the continuum as well as the discretised space.
Attention is also drawn to use of special symbols that the reader may find not in
common with other books on CFD. Thus, a mass-conserving pressure correction is

given the symbol p to contrast with the two other pressure corrections, namely, the
m

total pressure correction p and the smoothing pressure correction p . Similarly,
sm
the velocities appearing at the control-volume faces are given the symbol u f,i to
contrast with those that appear at the nodal locations, which are referred to as u i .
Again, in a continuum, the two velocity fields must coincide but, in a discretised
space, distinction between them preserves clarity of the physics involved. Novelty
will also be found in the discussion of physical principles behind seemingly mathe-
matical activity governing the topics of numerical grid generation and convergence
enhancement. It is not my claim that the entire material of the book can be covered
in a single course on CFD. It is for this reason that 1D formulations are empha-
sised through dedicated chapters. These formulations convey most of the essential
ingredients required in CFD practice.
The ambience of academic freedom, the variety of facilities and the friendly
atmosphere on the campus of IIT Bombay has contributed in no small measure to
this solo effort at book writing. I am grateful to my colleagues for their coopera-
tion in many matters. I am particularly grateful for having had the association of
a senior colleague like Professor S. P. Sukhatme (FNA, FNAE, former Director,
IIT Bombay). It has been a learning experience for me to observe him carry out a
variety of roles (including as writer of two well-received textbooks on heat transfer
and solar energy) in our institute with meticulous care. Hopefully, some rub-off is
evident in this book. I have also gained considerably from my Ph.D. and M.Tech. stu-
dents who through their dissertations have helped validate the computer programs
I wrote.
I would like to express my special gratitude to Mr. Peter Gordon, Senior Editor
(Aeronautical, Biomedical, Chemical, and Mechanical Engineering), Cambridge
University Press, New York, for his considerable advice and guidance during prepa-
ration of the manuscript for this book.