Abstract
Inspired by the revived interest in active flow control, tangential blowing was proposed from a slot near the front of the wing's upper surface. This effort stems from the pursuit of utilizing upper surface blowing, being one of the potential techniques used to control the boundary layer and alleviate stall in high angle-of-attack flight regimes. With the scope of understanding the flow field characteristics in the near wake of upper surface blowing, wind tunnel tests were conducted for a two-dimensional wing at low and high angles of attack. Hot-wire anemometry was employed to measure the velocity and turbulence profiles. The parameters included the rate of blowing, the angle of attack and the distance away from the trailing edge. Detailed results of the stream wise development of the mean velocity and turbulence were reported. The findings affirmed that tangential blowing was instrumental in energizing the flow in terms of an increase of the net velocity in the wake. Thereby, the drag would be lowered. Eventually, the noise level would be reduced. Both results could be valued as major achievements for the aviation industry.