An adaptive method is developed to improve the RANS model in hybrid RANS/LES simulations by using available upstream LES results. The method solves an inverse problem to get the anisotropic turbulent viscosity that perfectly matches the upstream LES solution at the RAN/LES interface and transfers that anisotropic information downstream to adaptively modify the RANS model by using the weak-equilibrium assumption. The proposed method was evaluated by applying it to two test problems, a channel and a periodic hill. Results obtained show the proposed approach to increase the accuracy and stability of the hybrid RANS/LES simulation. Since the RANS/LES interface is normal to the streamwise direction, this method is applicable to practical problems. Also, since the modification of the downstream RANS model is based on the anisotropic turbulent viscosity from the upstream LES solution, the method is adaptive to the problem being studied, which expands its applicability to a wider range of flow problems.
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