Large Eddy Simulation of Turbulent Flow Past a Backward Facing Step with a NewMixed Scale SGS Model

摘要

In this paper, a computational fluid dynamic prediction method is proposed, basedon the resolution of the full unsteady incompressible Navier-Stokes equations. An original numerical method is elaborated, corresponding to the three-dimensionnal cartesian version of the PEGASE code for DNS and LES of incompressible flows. A new improved subgrid-scale model, the Mixed Scale Model, is proposed. This model is based on both the largest resolved scale gradients and the smallest resolved scale kinetic energy. The problem of turbulent flow past a backward facing step is used in the present study to evaluate the potentiality of LES for the prediction and the analysis of separated flows.