SPACE-MARCHING METHOD ON UNSTRUCTURED GRID FOR SUPERSONIC FLOWS WITH EMBEDDED SUBSONIC REGIONS

A space-marching algorithm on an unstructured grid to solve supersonic flows that may contain embedded subsonic regions is proposed. The met hod employs a domain-marching algorithm in which a bandlike computatio nal subdomain is marched in the hyperbolic direction starting from the upstream boundary of the flowfield. A masking procedure is employed w here the outside of the selected domain is masked during the flux comp utations to minimize the overall arithmetic operations. The unmasked d omain is integrated in time to get a locally converged solution. If em bedded subsonic regions are present, the unmasked region is enlarged t o cover the entire subsonic regions surrounded by supersonic points. T he method is applied to calculations of a fully supersonic flow in a s cramjet and a supersonic flow with embedded subsonic regions around a blunt-nose body. It is demonstrated that the computational work can be reduced by as much as a factor of 10 as compared to conventional, tim e-marching unstructured grid methods.