INTEGRATION OF NAVIER-STOKES EQUATIONS USING DUAL TIME-STEPPING AND AMULTIGRID METHOD

Efficient acceleration techniques typical of explicit steady state sol vers are extended to time accurate calculations. Stability restriction s are greatly reduced by means of a fully implicit time discretization . A four-stage Runge-Kutta scheme with local time stepping, residual s moothing, and multigridding is used instead of traditional computation ally expensive factorizations. Two applications to natural unsteady vi scous flows are presented to check for the capability of the procedure .