Accession Number : AD0723989

Title :   Rotor Blade Boundary Layer Calculation Programs.

Descriptive Note : Final rept.,

Corporate Author : UNITED AIRCRAFT CORP STRATFORD CONN SIKORSKY AIRCRAFT DIV

Personal Author(s) : Clark,David R. ; Arnoldi,Douglas R.

Report Date : MAR 1971

Pagination or Media Count : 262

Abstract : The development of the turbulent compressible boundary layer on two typical helicopter rotors, for a range of hover conditions, has been calculated using two different analytical methods: the differential method, which uses the differential form of the boundary layer momentum equations and solves for the local velocity gradients, and the integral method, which uses the integrated form of the momentum equations and solves for the development of the characteristic boundary layer thickness parameters and skew angle. Both methods decouple the chordwise and spanwise boundary layer equations without making any small crossflow assumptions. The effects of rotational speed, vortex-induced crossflows, surface curvature, and applied chordwise pressure gradients were evaluated separately and in combination to simulate rotor airfoil boundary layer growth. (Author)

Descriptors :   (*ROTOR BLADES(ROTARY WINGS), *TURBULENT BOUNDARY LAYER), (*HELICOPTERS, HOVERING), HELICOPTER ROTORS, NAVIER STOKES EQUATIONS, VORTICES, CORIOLIS EFFECT, SHEAR STRESSES, ROTATION, SKIN FRICTION, NUMERICAL ANALYSIS, MATHEMATICAL MODELS

Subject Categories : Helicopters
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE