Scale Adaptive Simulation of Flows Past an Airfoil After Stall

The Scale Adaptive Simulation (SAS) models can keep standard RANS capabilities in stable flow regions but resolve turbulent structures in unsteady regions of flow field like LES. This RANS/LES property of SAS model relies on the v. Karman length-scale as a scale determining variable, which allows the model to automatically adapt to the appropriate length-scales in the simulated flows. Although SAS is young and still in developing, it has been proved to be very suitable for the predictions of massive separation flows. In the current study, the SST-SAS model is implemented in an in-house CFD code. First, the test case of decaying homogenous isotropic turbulence is selected for calibrating a constant associated with high wave number damping. Then, the simulation of flow past NACA 0021 airfoil at 60° attack angle is carried out for the validation of this turbulence model in our code. After that, the numerical results of NACA 0021 airfoil at a range of attack angles after stall are also presented for the comprehensive understanding of the SAS model.