Autorotating rotor with ornithopter-like flapping blades

Abstract Classification of the winged aircraft according to the character of wing (blade) motion in horizontal and vertical plane is presented. Design of a rotor, the blades of which are driven into rotation via flapping motion similar to the movement of an ornithopter's wing is proposed and the principle of operation is considered. Mathematical model of the aerodynamics of the autorotating rotor with flapping blades in hover is made on the base of the helicopter rotor blade-element theory. Geometric and kinematic parameters influence on the rotor lift and efficiency is analysed. It is shown that in hover the efficiency of an autorotating rotor with flapping blades is approximately equal to the one of a helicopter rotor.