Adaptive and fixed segmented domain decomposition multigrid procedures for internal viscous flows

Abstract

A segmented domain decomposition multigrid procedure is reviewed. The methodology is outlined for both an adaptive formulation applied primarily to inlet, nozzle and duct flows, and for a fixed, predetermined, subdomain formulation applied for turbomachinery geometries. The procedure has been considered for both low and high speed flows in two- and three-dimensions, and for laminar and turbulent-model applications. With these procedures, the grids remain uniform in each subdomain; although the global grid appears to be highly stretched. This formulation allows for computations with a high degree of accuracy and grid independence at reasonable computer cost. This is generally not possible to replicate with full domain multigrid procedures on stretched grids with large cell aspect ratio.