ABSTRAKT

Two hybrid RANS-LES models, termed HYB0 and HYB1 respectively, have been proposed. The HYB0 model is based on a simple near-wall mixing-length RANS model coupled with the Smagorinsky model in the off-wall LES region. The HYB1 model employs a one-equation model based on the transport equation for the turbulent kinetic energy. With both models, the RANS-LES matching is achieved by an adaptation of the turbulent length scale to patch the RANS-LES interface. The SGS model coefficients have been calibrated in LES for decaying homogeneous, isotropic turbulence. The hybrid approaches are verified in channel flow computations. Both models show reasonable performance of handling the RANS-LES coupling. In the test case with flow separation, the models have demonstrated good capabilities in reproducing the resolved flow and turbulence quantities in comparison with full-resolved LES data.