Evaluation of Detached Eddy Simulations for predicting the flow over periodic hills

Abstract

The performance of an hybrid LES–RANS strategy, the Detached Eddy Simulation (DES), as a predictive tool for turbulent channel flow with massive separation is scrutinized. This is undertaken in a collaborative effort involving five different flow solvers used by five different groups to cover a broad range of numerical methods and implementations. This paper concentrates on DES results obtained with a computational mesh of approximately one million cells. The results are compared to those obtained by Large Eddy Simulations (LES) using the standard and the dynamic Smagorinsky models and an alternative hybrid LES–RANS – all computed on the same grid. Data of a highly resolved LES (roughly 13 million cells) are used for reference. Furthermore, the impact of resolution and, therefore, the location of the LES–RANS interface is studied.