Control of trailing-edge noise from airfoil using a plasma actuator

抄録

Control of noise generation at an airfoil trailing-edge was conducted using a plasma actuator for an NACA0012 airfoil with an angle of attack of -2° at a chord Reynolds number Re = 1.6×10⁵, where the boundary-layer instability on the pressure side was responsible for the generation of the tonal trailing-edge noise. A thin electrode was installed uniformly in the spanwise direction at the maximum wing thickness location. The actuator was operated in pulsed (burst) mode to excite linear disturbances other than the naturally growing one artificially, and the responses of flow and tonal sound were examined. The naturally radiated tonal trailing-edge noise was found to be replaced by the weaker tonal sound at the bursting frequency when the bursting frequency was near that of the natural tone. It was also demonstrated that when the actuation frequency was far from that of original (natural) sound, the boundary-layer transition was dominated by naturally unstable broadband disturbances, leading to complete suppression of the tonal trailing-edge noise.