Scale adaptive simulations of unsteady flow around naca0021 airfoil at 60° angle of attack

Reliable and accurate simulation of high Reynolds number flow around airfoils at high angle of attack is a challenging computational fluid dynamics (CFD) problem of significant importance in aerospace industry. In this study, scale adaptive simulations have been performed on the unsteady flow around NACA0021 airfoil at 60° angle of attack. Detailed investigations are carried on the effect of time step, the effect of span-wise length, the effect of grid resolution on the target of validation and verification. The best accuracy can reach 0.25% in terms of mean lift coefficient and 1.1% in terms of mean drag coefficient. Compared to other hybrid RANS/LES simulations, SAS simulations show a similar accuracy to that of PANS and IDDES simulations, much better than the accuracy of DES and OES simulations. All the hybrid RANS/LES simulations show better prediction than the URANS simulation not only in mean force coefficients but also with more vortical structures resolved.