Analysis of Transonic Pitching Airfoil Flows at Re c =1.2×10 7 Using Wall-Modeled LES

This study conducts the wall-modeled large-eddy simulations (WMLES) of transonic flow over a forced pitching airfoil at a high Reynolds number to investigate the prediction accuracy of the WMLES. The flow around pitching NACA64A010 airfoil at mean angles of attack of alpha_m=0 and 4 deg are simulated. The large shock-induced separation of the boundary layer is observed at the high mean angle of attack of alpha_m=4 deg. The obtained results by the present WMLES show good agreement with the experimental data, which indicates the effectiveness of the WMLES for predicting the flow in transonic regime over a pitching airfoil. Through the analysis of energy transfer from flow into the airfoil, the contributions of flow to the instability of pitching airfoil are investigated. At alpha_m=0 deg, the shock wave motion leads to the energy inflow to the airfoil and contributes to the instability of airfoil oscillation. On the contrary, at alpha_m=4 deg, the shock wave motion affected by the boundary layer separation contributes to the stability of airfoil oscillation.