EVALUATION OF TURBULENCE MODELS USING LARGE-EDDY SIMULATION DATA

The performance of some of the most commonly used eddy viscosity turbulence models to predict separated boundary layer flows in adverse pressure gradient has been evaluated against large eddy simulations. The LES results were used to assess the consistency of the different terms in the k-epsilon, zeta-f, k-omega and Spalart-Allmaras models. For the separated boundary layer; the eddy-viscosity assumption works' well, and anisotropic effects are not significant. However, the near-wall treatment used in k-epsilon models was found to have a critical effect on the predictive accuracy of the flow (and, in particular, of separation and reattachment points). None of the wall treatments tested resulted in accurate prediction of the flow field.