MS 128 NASA Langley Research Center Hampton, VA 23681

B. Diskin

R. Mineck

Abstract

The ingredients for attaining textbook multigrid efficiency in solution of CFD problems are discussed as they arise in application to stagnation flow problems. The ingredients include principal linearization, factorizable schemes, local relaxation, etc. Textbook multigrid efficiency is demonstrated for stagnation flows with a pressure-equation formulation of the incompressible fluid equations. Both inviscid and viscous flows over a range of Reynolds number are considered. Convergence of algebraic errors below discretization errors in one full multigrid cycle is attained using flow-dependent relaxation schemes. The residual convergence rates for the systems are the same as for scalar elliptic equations on the same grid.