The Flapping Propulsion Rotor - Single Rotor without Tail Rotor

Abstract

The term “Flapping Propulsion Rotor” has first been used by H.G. Küssner in Germany in the 30ies of the last century. Based on a patent, Küssner has developed a wind tunnel model to demonstrate his concept of a rotor with a tip path plane tilted against the rotor axis. He could show experimentally that with this arrangement the reaction torque of the rotor could completely be compensated. The rotor then works without any additional device like tail rotor or second counter rotating rotor. In the present numerical investigations it will first be shown that the flapping rotor test data match sufficiently the calculations. Extending the concept (which Küssner had already proposed) to a combination of flapping and pitching blades it will be demonstrated that then the efficiency and range of applicability can be improved consid-erably