Static-thrust Tests of Six Rotor-blade Designs on a Helicopter in the Langley Full-scale Tunnel

Measurements of the static-thrust performance of six sets of rotor blades mounted on a helicopter fuselage have been made in the Langley full-scale tunnel. The rotor blades differ in surface condition, pitch distribution, airfoil section, plan form, and solidity. These differences are largely unsystematic. The variation of rotor thrust coefficient with torque coefficient and the power required to hover are compared for each set of blades. Because of the indeterminate condition of ground restraint caused by the wind-tunnel balance house and test-chamber walls, the absolute magnitude of the data is questionable but the comparative results are believed to be reliable.