The Effects of Blowing Parameters on the Dynamic Stall Control of an Airfoil

In view of the promising application prospects and potential of blowing control technology in dynamic stall control of airfoil, based on the dynamic pressure measurement model of CRA312 airfoil with blowing slots, the effects of blowing slot height, slot position and mass flow rate on airfoil’s stall control were experimentally investigated under static and oscillatory conditions, respectively. The results show that for the static airfoil, the stall can be effectively controlled by blowing at 5% c and 10% c, and the optimal blowing position is at 5% c. Compared with 0.13% c and 0.1% c slot height, the blowing of 0.067% c slot height can achieve better stall control effect, which can increase the maximum lift coefficient by 18.6% and delay the stall angle by about 10°. The larger the mass flow rate of blowing, the better effect of the stall control. When the mass flow rate blowing reaches a certain value, the control efficiency decreases. For the oscillating airfoil, the influence law of blowing parameters is consistent with that of the static airfoil. Blowing control can significantly reduce the hysteresis loop area of lift coefficient and reduce the peak value of drag and moment coefficient. The optimal control of lift coefficient of airfoil is achieved by blowing at 5% c, with the maximum lift coefficient of the dynamic airfoil increased by 7.53% and the hysteresis loop area reduced by 67%. Blowing at 10% c is optimal for the torque control of the oscillating airfoil, with the maximum head-down torque coefficient reduced by 72.6%. Flow field display tests show that the dynamic stall of the airfoil can be effectively controlled by blowing.