Parallel Program Complex for Unsteady Viscous Gas Flow Simulation

This paper concerns with the future development of a parallel program package for 3D viscous gas flow simulation presented in [1]. One of the restrictions of this package was its orientation on use of only structured non-uniform meshes. This restriction may be rather taxing when high accuracy resolution of the solution particularities in small regions is needed. Using of regular non-uniform meshes in such situation leads to inevitable spreading of fine mesh into regions where it is not necessary. So we will have a waste of computational time, especially in 3D case. This problem may be avoided by use of unstructured meshes, but the convenience and simplicity of difference schemes on regular grids enforced us to search a way of solving a problem in the frames of structured meshes. It is naturally in this situation to use multiblock grids where different subregions have their own grids. A variant of such approach is the use of nested (or locally refining) grids. The parallel program complex [1] based on explicit finite difference schemes, which are constructed as an approximation of conservation laws was supplemented with the possibility of rectangular nested grids usage. Special utility for nested grid partitioning was created. The program complex was tested on 2D and 3D subsonic and supersonic problems. The calculations were held on multiprocessor computer system MCS-1000M situated in Joint Supercomputer Center (Moscow, Russia). This work was supported by Russian Foundation for Basic Research (grants No. 02-0790168, 02-01-00700 and 03-01-00606). Eugene V. Shilnikov.