AN ADAPTIVE CARTESIAN GRID METHOD FOR UNSTEADY COMPRESSIBLE FLOW IN IRREGULAR REGIONS

In this paper we describe an adaptive Cartesian grid method for modeling time-dependent inviscid compressible flow in irregular regions. In th is approach a body is treated as an interface em bedded in a regular Cartesian mesh. The single grid algorithm uses an unsplit second-order Godunov algorithm followed by a corrector applied to cells at the boundary. The discretization near the fluid-body interface is based on a volume-of-fluid approach with a redistribution procedure to maintain conservation while avoiding lime step restrictions arising from small cells where the boundary intersects the mesh. The single grid Cartesian mesh integration scheme is coupled to a conservative adaptive mesh refinement algorithm that selectively refines regions of the computational grid to achieve a desired level of accuracy. Examples showing the results of the combined Cartesian grid integration/adaptive mesh refinement algorithm for both two- and three-dimensional flows are presented. (C) 1995 Academic Press, Inc.