ボルテックス・リング状態におけるヘリコプタ・ロータの実験的研究

Abstract

Unsteady aerodynamic characteristics of a single rotor as well as a tandem rotor operating in the vortex ring state have been experimentally investigated. The histories of thrust, torque and rpm of the rotor were measured by use of sensing devices which were installed on the shaft of the rotor. The thrust fluctuates violently while the torque fluctuates very little. The induced power obtained from thrust and torque data has been compared with that obtained from the momentum theory. Existence of periodicity in the thrust fluctuation has also been observed in some regions of the vortex ring state.