A hybrid RANS/LES approach with scale-adaptive capabilities for highly separated flows |
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| Authors: | Weilin Zheng Fan Xie Chao Yan |
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| Institution: | 1. Liaoning Key Lab of Advanced Test Technology for Aerospace Propulsion System, Shenyang Aerospace University, Shenyang, People’s Republic of China;2. AVIC Shenyang Aircraft Design and Research Institute, Shenyang, People’s Republic of China;3. School of Aeronautics Science and Engineering, Beihang University, Beijing, People’s Republic of China |
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| Abstract: | A new hybrid RANS/LES approach with scale-adaptive capabilities is developed. The blending function in the SST model is adopted to prevent the invasion of the von Karman length scale to the RANS region, and the compressibility correction proposed by Wilcox is incorporated to produce a realistic shear layer development in compressible flows. The new model is validated for a subcritical flow past a circular cylinder and a supersonic base flow. Time-averaged turbulent statistics predicted by the new model show fairly good agreement with the experimental data, slight improvements over DES simulations, and are much better than SAS results. The main advantage of the new model over the DES method is that the distribution of the blending function reflects local vortex structures instead of grid spacing in the turbulent wake. The sequence of the effect intensity of the compressibility correction from strong to weak is SAS, the new model and DES. |
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| Keywords: | Hybrid RANS/LES model Von Karman length scale blending function compressibility correction highly separated flows |
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