A multigrid lu-ssor scheme for the solution of hypersonic flow problems

摘要

The main purpose of this paper is to investigate the possibility of accelerating the convergence of the implicit Lower-Upper Symmetric Successive Overrelaxation (LU-SSOR) scheme for hypersonic flows. It is shown that this can be accomplished by implementing the scheme into a multigrid method. The problem of poor high frequency damping properties of the LU-SSOR scheme is cured by a moderately increased implicit dissipation and by multiple time steps on all grids. The efficiency of a multigrid LU-SSOR scheme is demonstrated for different hypersonic test cases. in comparison to the widely used single-grid LU-SSOR scheme, the CPU-times are reduced by factor 3.7 for inviscid any be more than factor 4.9 for viscous flow problems.