Helicopter vibration suppression via multiple trailing edge flaps controlled by resonance actuation system

An active vibration control method for the multiple trailing-edge flaps configuration is proposed and evaluated via simulation. The concept involves deflecting each individual trailing-edge flap using a compact resonance actuation system. Each resonance actuation system yields high authority, while operating at a single frequency. An aeroelastic model is developed for a helicopter rotor with trailing edge flaps. The rotor blade airloads are calculated using quasi-steady blade element aerodynamics with a free wake model for rotor inflow. A compressible unsteady aerodynamics model is employed to predict the incremental trailing edge flap airloads. Both finite wing effects and actuator saturation are included in the simulation. A numerical simulation has been performed for the resonance actuation system tuned to 4/rev frequency and the steady-state forward flight (μ=0.15̃0.35). It is demonstrated that multiple trailing-edge flap configuration with the resonance actuation system can outperform single- and dual-flap configurations by achieving more vibration reduction within available actuator authority. An analysis and parametric study is conducted to explore the finite wing effect of trailing-edge flaps and actuator saturation. Within the available actuator authority, multiple-flap configuration reduces the vibration by 91% and 79%, in low- and high-speed flight conditions, while single-flap one does it by 35% and 56%.