ACTIVE-PASSIVE HYBRID CONTROL OF SHOCK BUFFET

Shock buffet is a significant self-excited shock vibration phenomenon induced by shock wave boundary-layer interaction. For a swept wing, the unsteadiness contains the chordwise oscillation as well as the spanwise fluctuation of the shock, displaying the wideband and multimodal characteristics. Independent active or passive control can only reduce the amplitude of buffet load, while significant pressure fluctuations still persist. An active-passive cooperative control (APCC) scheme, which combines shock control bump (SCB) and trailing edge flap, is proposed to eliminate the oscillating loads of shock buffet. SCB is long in chordwise direction but narrow in spanwise direction, while its height remains small, which basically doesn’t affect lift-drag ratio of wing, and can eliminate spanwise fluctuation of shock wave. The role of trailing edge flap is the same as that of 2D shock buffet active control, and it’s used to eliminate chordwise oscillation of shock wave. The simulation results show that APCC can basically eliminates the pressure fluctuations on wing.