Multigrid Convergence Acceleration for Non-Reactive and Reactive Flows

The numerical simulation of chemically reacting flows requires extremely long CPU times if finite-rate chemistry is employed. Multigrid methods belong to the most promising methods for convergence acceleration and are widely used for non-reactive subsonic and transonic flows. This paper presents the application of an implicit multigrid algorithm to non-reactive and reactive turbulent high speed flows. Special care is required for the treatment of shock waves as well as chemical and turbulent source terms to enable convergence. CPU time reductions by a factor of at least 4 are presented for a non-reactive flow with streamwise air injection and a lifted methane-air flame. All calculatione are performed on the NEC SX-4.