Large Eddy Simulation of a symmetric bump on structured and unstructured grids, comparisons with RANS and T-RANS models

One of the symmetric bumps available from the experiment of Simpson et al. (2002) is investigated in the present paper with various models. The Reynolds number based on the height of the hill and the maximum velocity at the inlet is 130 000. The unstructured collocated finite volume code Saturne is used for all the computations. Two RANS, a T-RANS and a Large Eddy Simulation (LES) calculation are first reported using a structured grid with about 900 000 cells. Both RANS models and LES fall in predicting the appropriate velocity profiles. T-RANS produces better results but still not the correct velocity field. Then, unstructured meshes using non-conforming faces are used for a better near wall resolution, with still less than a million cells. The obtained results are much better than in the previous simulations.