EXPLOITING THE FLEXIBILITY OF UNSTRUCTURED GRIDS FOR COMPUTING COMPLEX FLOW PATTERNS MORE PRECISELY

In comparison to structured meshes, the most important advantage of un structured grids is geometrical flexibility provided by the lack of st rict topological rules. The present work proposes techniques to exploi t this feature by generating and optimizing unstructured meshes to ach ieve more accurate results in less computing time. In this article a s uited layout of initial grids is shown to improve convergence speed wh ile reducing memory requirements and preserving numerical accuracy. To control the process of solution adaptive grid optimization, normalize d gradients of transport variables are proposed. These quantities prov e to be effective in several test cases and a demanding turbomachinery application. Although the calculations were carried out assuming two- dimensional flow, the methods introduced here can be applied under thr ee-dimensional conditions without difficulty. (C) 1998 Elsevier Scienc e Inc. All rights reserved.