Accession Number : AD0783440

Title :   Experimental Investigation of the Effects of Helicopter Rotor Design Parameters on Forward Flight Stall Characteristics.

Descriptive Note : Final rept. Jan 72-Dec 73,

Corporate Author : UNITED AIRCRAFT RESEARCH LABS EAST HARTFORD CONN

Personal Author(s) : Bellinger,E. D. ; Patrick,W. P. ; Greenwald,L. E. ; Landgrebe,A. J.

Report Date : APR 1974

Pagination or Media Count : 144

Abstract : An experimental investigation was conducted to determine the effects of number of blades, twist, aspect ratio, camber, taper ratio, and torsional frequency on helicopter rotor stall characteristics in forward flight. The tests were conducted in the low-speed UARL 4- x 6-ft wind tunnel with 4.7-ft-diameter model rotors having flapping articulation. Stall conditions were approached by means of increasing rotor shaft angle at fixed collective pitch. Torsional frequency was varied by using a special blade root flexure which would produce the required rigid blade torsional frequencies. Rotor performance, blade response, and boundary layer separation data were acquired to determine the occurrence and extent of blade stall. (Modified author abstract)

Descriptors :   *HELICOPTER ROTORS, STALLING, ROTOR BLADES(ROTARY WINGS), ASPECT RATIO, WIND TUNNEL MODELS, BOUNDARY LAYER FLOW, FLOW SEPARATION

Subject Categories : Aerodynamics
      Helicopters

Distribution Statement : APPROVED FOR PUBLIC RELEASE