Aeroelastic Analysis of a Cycloidal Rotor Under Various Operating Conditions

The aeroelasticity of a cycloidal rotor in forward flight is investigated using an analytical and a numerical model; the latter is based on a multibody dynamics approach. Three experimental sources are used to validate the multibody model. The influence of the number of blades, their stiffnesses, and their skin thicknesses are investigated. At high pitch angles, before stall and flexibility effects occur, increasing the number of blades produces more thrust for the same power. Flexibility and skin thickness considerably affect the required pivot rod strength and blade deformation. Simply supported blades exhibit severe deformations when compared to clamped blades. Thrust and power are both influenced in a similar and moderate way by flexibility. The rotor response to wind gusts is also analyzed. The angular velocity of the rotor significantly affects the response of the rotor to wind gusts. The direction of the gusting wind has an important influence on power, whereas thrust increases regardless of wind direction. Finally, the rotor response lags minimally behind the arrival of the gust.