Wall-modeled large-eddy simulation of high Reynolds number flow around an airfoil near stall condition

This paper investigates the capability of large-eddy simulation (LES) with wall-modeling in predicting transitional and separated flow over an airfoil near stall condition at high Reynolds number (chord based Re_c=2.1×10⁶). By incorporating the non-equilibrium effects and transition treatment in the wall model, the wall-modeled LES well predicts the mean and turbulence statistics in the region of laminar separation, turbulent transition, turbulent reattachment, and initial-mid developments of attached turbulent boundary layer. The present LES with non-equilibrium wall-model reproduces the dynamics of two-dimensional intermittent laminar separation vortices, hairpin-like vortices, and breakdown of the laminar separation vortices to three-dimensional turbulent structures that allow the boundary layer to reattach. Comparisons between the non-equilibrium and equilibrium wall-models highlight the importance of including the non-equilibrium effects in the model.