Transonic Buffet Active Control with Local Smart Skin

Abstract

Transonic flight has high economic benefits, but the appearance of transonic buffet limits the flight envelope. The shock control bump currently used for transonic buffet suppression tends to degrade the aerodynamic performance of the non-buffeting state. In this study, a smart skin system is used to eliminate the fluctuating load of transonic buffet by measuring the airfoil lift coefficient as the feedback signal and adjusting the local skin height using data-driven, model-free adaptive control. Since the actuator height is dynamically adjusted only after the occurrence of transonic buffet, the smart skin can completely suppress the fluctuating load and does not affect the aerodynamic performance in the non-buffeting state. The suppression effect of the proposed smart skin on transonic buffet is verified by numerical simulation of the flow. The simulation results show that due to the introduction of closed-loop control, the fluctuating load of transonic buffet can be effectively suppressed for different positions and maximum heights of the actuator. Even when the flow state changes, the robust smart skin system can also achieve the control goal. Therefore, smart skins combining flexible materials and control technologies have the potential to effectively improve the aerodynamic performance of aircraft.

Closed-Loop Control of Transonic Buffet Using Active Shock Control Bump

“…Instead, the bump height is assumed to be an active control variable according to the feedback signal, namely the lift coefficient. Note that a similar control method, named "local smart skin", has been previously proposed by Ren et al [32]. The current study will further extend their study on a well-understood buffet case and demonstrate the advantages of the active shock control bump in comparison with the reference active trailing edge flap.…”