Semi-implicit preconditioning for wall-bounded flow

Abstract

Large eddy simulations (LES) of high speed compressible viscous flow require high space resolution as well as short time steps if explicit time stepping is used. A semi-implicit preconditioning scheme specially suitable for wall-bounded flow is developed which, when combined with an explicit time stepping algorithm, makes much larger time steps possible than with the explicit scheme alone. The method is validated for developing turbulent channel flow and applied to a transonic flow with shock wave turbulent boundary layer interaction. In both cases, the computational time saved is measured. Finally possible developments of the method are discussed