Numberical simulation of separation equilibrium of flow around 2D wing configuration at high angle of attack

The Reynolds-Averaged Navier-Stokes (RANS) method is conducted to simulate flow around airfoil at high AOA. The separation is well captured using two-equation shear stress transport (SST/k-ω) turbulence model accounting for turbulence motions. Calculation shows that the wing separation vortices are stable in several equilibrium stats, with the wing thickness up to a certain criteria, and AOA in a certain range. Meanwhile the separation transfers from one stable state to anther when certain disturbance is intruded. Comparing different disturbances, the translation is inclined to happen under heaving-pitching motions rather than forward-afterward vibrations. That is the exact one of most important reasons for aerodynamic loads data variation of airfoil at high AOA in wind tunnel test.