Numerical investigation of dynamic stall control using variable droop leading edge airfoil

Numerical simulation for the variable droop leading-edge(VDLE) concept proposed to control the compressible dynamic stall of the VR-12 airfoil was presented. Computational results validate that VDLEcan decrease considerably the maximum drag and improve the minimum pitching moment simultaneously while the lift is maintained almost at the same high level.The reason for VDLEhaving achieved these benefits,from the perspective of flow mechanism,is its ability to eliminate completely the dynamic stall vortex occurred on the baseline.Investigation of the effects of parameters shows that the control benefits of VDLEare not sensitive to the variation of Mach number,reduced frequency or drooping control methods,which implies that the VDLEis a robust control method for the compressible dynamic stall of airfoil.