The mechanism by which periodic blowing and suction improves lift and stall angle of a 70 degree sweep delta wing is investigated in water tunnel experiments using PIV measurements. Periodic sinusoidal blowing and suction with zero net mass flux is applied at the leading edge of the wing.
The experiments were conducted at a freestream flow speed of 0.126 m/s, corresponding to a root chord Reynolds number of 40,000. The wing was kept at an angle of attack of 35° for this study. A forcing frequency of F+ = 1.75 was used, which was shown in previous research to be most effective in improving lift. The momentum coefficient was kept constant at (cm ) of 0.004.