in this chapter we will attempt to answer the following questions.
what is numerical grid generation
why and when do we use it
how do we use it
to answer these questions reference will be made mainly to problems in fluid mechanics
however it is important to realize that the concept and techniques described can be used in any problem involving the numerical solution of a single or a system of partial differential equations
furthermore the discussion will be restricted to two-dimensional problems foe the sake of convenience in explaining the idea extensions to three-dimensional problems are straightforward
lastly we point out that the discussion of grid generation contained herein is of an instructional nature
we have not attempted to give a comprehensive study of grid generated techniques
the reader is referred to the review article by thompsom et al. for an excellent survey of the field of grid generation up until 1982