03.3 - Basic Fluid Dynamics and Flow Control
ACTIVE-PASSIVE HYBRID CONTROL OF SHOCK BUFFET
C.Q. Gao, China; K. Ren, China; W.W. Zhang, China
An active-passive hybrid control method is proposed to eliminate the shock buffet flow over wings. Passive control uses SCB to suppress spanwise instability modes. The active control takes the lift coefficient as the feedback signal, and adopts the model free adaptive control method to adjust the rotation angle of the trailing edge flap to achieve the control of chordal shock wave oscillation. When using only the wingtip flap for closed-loop control, the amplitude of lift coefficient fluctuation can be reduced. This is due to the cancellation of the impact of shock wave oscillation and trailing edge flap deflection, resulting in a reduction in the amplitude of lift fluctuation. Using SCB and trailing edge flap hybrid control can basically eliminate lift fluctuation. Moreover, due to the effect of SCB, the shock wave moves backward at the wing tip, and the lift coefficient slightly increases. From the pressure RMS contour, it can also be seen that the pressure fluctuation on the wing surface has basically disappeared.