Smart structures in the active control of blade vortex interaction

During the operation of a rotorcraft, rotor blades interact with vortices shed by preceding blades. As a result of the interaction, large pressure pulses are created at the leading edge of the airfoil. In this paper, feasibilities studies have been conducted to investigate if a combination of active camber changes by the use of smart structures concepts and optimum control techniques can be used to reduce the magnitude of the large pressure pulse created by the interaction of the airfoil and vortices shed by the preceding blade. The optimum control techniques used in this paper include a technique based on the use of a quadratic performance index and a technique based on H[infinity] control concepts.