Dynamic stall suppression for rotor airfoil based on inflatable leading edge technology

The occurrence of dynamic stall will result in high vibration torque loads and limit the flight envelope of a helicopter at high speed and load. Through the method of computational fluid dynamics (CFD), dynamic stall suppression for SC1095 helicopter rotor airfoil based on inflatable leading edge (ILE) technology is studied. The control mechanism of dynamic stall suppression and the effect of structure and inflating process of ILE are analyzed. The result shows that the dynamic stall suppression method based on ILE is effective. The bigger the expansion of the ILE, the better the effect of the ILE on dynamic stall suppression. However, if the ILE is too great, the effect will become weak. If the expansion of the ILE reaches the maximum when the airfoil pitches to the maximum angle of attack, the best control performance can be achieved. The duration of the maximum expansion state of the ILE has minor effect on the control performance. The angle of attack at which the ILE starts to swell has a great effect on the control ability. The position which connects the ILE and the airfoil has a great effect on dynamic stall suppression. A longer fairing section of the ILE has a better effect on dynamic stall suppression.