A robust elliptic grid generator

A variational principle is proposed that results in a robust elliptic grid generator having many of the strengths of original Winslow or homogeneous Thompson-Thames-Mastin method (hTTM). The new grid generator places grid lines more uniformly over the domain than does hTTM, without loss of orthogonality. Numerically generated examples are given to demonstrate these effects. Grid quality measures are introduced to quantify differences between discrete grids. Both the hTTM and the new grid generator can generate folded grids on certain pathological regions, but overall they are very robust. Grid weighting for solution-adaptive calculations is briefly considered. Generalization of the new method to surface and volume grid generation is straightforward.