Simultaneous BVI Noise and Vibration Reduction in Rotorcraft Using Microflaps Including the Effect of Actuator Saturation

A dual and a five-microflap configuration of a sliding micro ap with a height of 1.5% of blade chord are studied to determine their effectiveness in simultaneously reducing rotorcraft vibrations and noise under heavy BVI conditions in descending ight at μ = 0:15. Closed-loop control studies were conducted on a hingeless rotor configuration resembling MBB BO-105, using the adaptive Higher Harmonic Control (HHC) algorithm. The performance of the micro ap was also compared to a conventional trailing-edge plain ap. The results demonstrate the effectiveness and control authority of the micro ap for simultaneous BVI noise and vibration reduction in rotorcraft. Finally, a new saturation control algorithm is developed for limiting the micro ap or ap de ections such that the best utilization of on-blade controllers implemented through multiple control surfaces is achieved. The performance of the new algorithm is compared to the existing ones using the dual and five-microflap configurations.