FULL-SCALE INVESTIGATION OF THE AERODYNAMIC CHARACTERISTICS OF A TYPICAL SINGLE -ROTOR HELICOPTER IN FORWARD FLIGHT

摘要

As part of the general helicopter research program being under-taken by the National Advisory Committee for Aeronautics to provide designers with fundamental rotor information, the forward-flight performance characteristics of a typical single-rotor helicopter, which is equipped with main and tail rotors, have been investigated in the Langley full-scale tunnel. The test conditions included operation at tip-speed ratios from 0.10 to 0.27 and at thrust coef¬ficients from 0.0030 to 0.0060. Results obtained with the produc¬tion rotor were compared with those for an alternate set of blades having closer rib spacing and a smoother and more accurately con¬toured surface in order to evaluate the performance gains that are available by the use of rotor blades having an improved surface condition.