Parameters effect of pulsed-blowing over control surface

Control surface, which is often located in the trailing edge of wings, is important in the attitude control of an aircraft. However, the efficiency of the control surface declines severely under the high deflect angle of the control surface because of the flow separation. To improve the efficiency of control surface, this study discusses a novel flow control technique aimed at suppressing the flow separation by pulsed blowing at the leading edge of the control surface. Results indicated that flow separation over the control surface can be suppressed by pulsed blowing, and the maximum average pitching moment coefficient of the control surface can be increased by nearly 90% when average blowing momentum coefficient is 0.03 relative to that of without blowing. Moreover, the lift coefficient of the control surface can be 95% times higher than that of without blowing, and the drag coefficient of the control surface can be reduced by 43% compared with that of without blowing. Finally, this study shows that the average blowing momentum coefficient and non-dimensional frequency of pulsed blowing are two of the key parameters of the pulsed blowing control technique. Both experimental and numerical simulations are used in this study. The experiment is completed in D-4 wind tunnel of Beihang University under conditions of Re 0.8×106Re 0.8×106.