Accession Number : ADA113988

Title :   Performance Testing of a Main Rotor System for a Utility Helicopter at 1/4 Scale.

Descriptive Note : Technical rept.,


Personal Author(s) : Berry,John D

PDF Url : ADA113988

Report Date : Apr 1982

Pagination or Media Count : 49

Abstract : Performance measurements on two rotor systems were made for hover and for simulated forward flight in the Langley 4- by 7-Meter Tunnel. The first rotor system, tested as a 'baseline', was a dynamically accurate, 1/4-scale model of the current rotor system on the UH-1 helicopter. The second rotor system, designed for advanced performance with similar dynamics, varied from the baseline system in airfoil cross section, in twist, and in geometric taper of the planform. In hover out of ground effect, the advanced rotor demonstrated a maximum improvement of 10 percent in the figure of merit for an isolated rotor when compared to the baseline rotor. A thrust improvement of about 7 percent was shown for the helicopter (including the fuselage downloading effects) using the advanced rotor in hover out of ground effect, at a torque coefficient equivalent to full power of the full-scale vehicle at significant reductions in torque (power) required throughout the range of advance ratios (speeds) tested. Reductions of up to 17 percent in required torque were measured, with the larger reductions occurring at the higher advance ratios and higher lift values. (Author)

Descriptors :   *Helicopter rotors, *Rotor blades(Rotary Wings), Performance(Engineering), Hovering, Aerodynamic characteristics, Flight maneuvers, Flight simulation, Thrust, Torque, Lift, Ground effect, Wind tunnel tests, Scale models, Helicopters, Rotary wing aircraft

Subject Categories : Aerodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE