3D low hill with complex separation

16.3 Conclusions

Simulations of the flow over a symmetric, three-dimensional hill have been presented and the results have been compared with experiments. RANS, LES and hybrid LES-RANS have been used. In the RANS simulations, different turbulence models have been used, including full Reynolds stress models, explicit algebraic Reynolds stress models and two-equation eddy-viscosity models. A simple Smagorinsky model was used in the LES-simulations, and a k_sgs one-equation was used in the hybrid LES-RANS-simulations. The conclusion is that all RANS simulations fail completely in capturing the flow on the lee-side and downstream of the hill while both LES and hybrid LES-RANS give results which are in fairly good agreement with experiments.