Large-eddy simulations of a separated plane diffuser

We present Large-Eddy Simulations (LES) of a weakly separated diffuser. The influence of mesh resolution and the choice of subgrid model is investigated. Three resolutions ranging from 1.5 to 6.5 million cells are computed. The influence of the subgrid model is studied on the coarsest mesh using no subgrid model, the standard Smagorinsky model, the dynamic Smagorinsky model and the dynamic localization model. Furthermore, some flow features are investigated using the results of the fine mesh simulation. The application of LES to a gas turbine prediffuser flow is briefly described.