Hi all,

Why is grid transformation necessary with the finite difference method? Is it necessary for the finite volume method, and if not, why not?

Thanks in advance,

Mark.

Grid transformation is not necessary for the finite element method. However, it is necessary to compute integrals over each element in the process of computing and assembling the matrix elements of the global stiffness matrix, mass matrix, body force matrix and surface integrals, etc. If the elements don't have a simple shape (like triangular or rectangular), then the integrals may be difficult to evaluate. The transformation maps the (perhaps) odd shaped element to a simple shape (like a square) where the integrals are easier to evaluate.