SOLUTION-BASED GRID ADAPTATION THROUGH SEGMENTED MULTIGRID DOMAIN DECOMPOSITION

A solution-based grid adaptation method that combines elements of the multigrid method for solution acceleration and the domain decompositio n philosophy for grid optimization is described. Unlike other solution -based adaptive gridding schemes, wherein the overhead of recomputing the grid and re-evaluating the solution on the adapted grid leads to h igher computational costs compared to a nonadapted calculation, the pr esent methodology reduces the computational time required to obtain th e solution. The computational effort involved in the present calculati on is significantly lower than a nonadapted calculation that utilizes the multigrid method purely as a convergence acceleration tool. In add ition to convergence acceleration, the multigrid framework provides a mechanism of information transfer from regions wherein grid refinement is specified to unrefined coarse grid regions. The basis for domain d ecomposition in the current procedure is the variation in grid refinem ent requirements for each coordinate direction in different portions o f the flow field. The method is demonstrated herein on an efficient se t of governing equations termed the reduced Navier-Stokes equations, a pplied in conjunction with a set of physical boundary conditions. The governing equations are discretized through a pressure-based flux-spli tting procedure that is uniformly applicable from incompressible to su personic Mach numbers. (C) 1997 Academic Press.