Accession Number : ADA185223

Title :   A Note on the Use of Symmetric Line Gauss-Seidel for the Steady Upwind Differenced Euler Equations,

Corporate Author : STANFORD UNIV CA CENTER FOR LARGE SCALE SCIENTIFIC COMPUTATION

Personal Author(s) : Mulder, William A

PDF Url : ADA185223

Report Date : 29 Jul 1987

Pagination or Media Count : 11

Abstract : Symmetric Line Gauss-Seidel relaxation, when used to compute steady solutions to the upwind differences Euler equations of gas dynamics, is shown to be unstable. The instability occurs for the long waves. If SLGS is used in a multigrid scheme, stability is restored. However, the use of an unstable relaxation scheme will not provide a robust multigrid code. Damped Symmetric Point Gauss-Seidel relaxation is stable and provides similar multigrid convergence rates at much lower cost. However, it fails if the flow is aligned with the grid over a substantial part of the computational domain. Damped Alternating Direction Line Jacobi relaxation can overcome this problem.

Descriptors :   *GAS FLOW, INVISCID FLOW, COMPRESSIBLE FLOW, EULER ANGLES, RELAXATION TIME, CONVERGENCE, SYMMETRY, FOURIER ANALYSIS, FREE STREAM

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE