SIMULATIONS OF SEPARATED FLOWS WITH SUBGRID MODELS

The Pegase code for direct numerical simulation has been modified to p erform computations of separated flows with subgrid scale models. The configuration retained is that of the backward facing step, with a Rey nolds number Re-h (based on the step height) of 11,200. Special attent ion was focused to the subgrid scale model discretization and to the n umerical treatment of the convection term. Simulations were performed with two standard models - Smagorinsky and dynamic - and with a new mi xed-scale model. The results obtained are compared with the experiment al data of Eaten and Johnston. The dependency of the results on the su bgrid scale model is analyzed, and the origin of certain observed disc repancies is discussed.