Experiments with Tangential Blowing to Reduce Buffet Response on an F-15 Model

摘要

A concept employing upstream tangential blowing was investigated experimentally as a means for mitigating buffet response of fighter aircraft empennage, notably twin vertical tails. Wind-tunnel tests of a 4.7%-scale model of the F-15 fighter were conducted in the Subsonic Aerodynamics Research Laboratory, Wright-Patterson Air Force Base, Ohio. Tangential blowing was introduced from three points: the nose, the wing-root leading edge, and the gun bump, flowing back to the tails in a Coanda-like effect. Several blowing pressure values were used at angles of attack from 0 to 32 deg. Blowing was seen to lower the buffet pressures on the tails and to reduce the structural response. The level of response, and trends varied somewhat between bending and torsion moments and acceleration data. Also, the trends depended upon angle of attack and yaw, and frequency bands. In some cases blowing actually increased the response slightly. The most effective blowing position was the wing blowing position; the gun position was the next most effective; and the nose position was the least effective.