Accession Number : AD0723989

Title :   Rotor Blade Boundary Layer Calculation Programs

Descriptive Note : Final rept.

Corporate Author : UNITED TECHNOLOGIES CORP STRATFORD CT SIKORSKY AIRCRAFT DIV

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

PDF Url : AD0723989

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.

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

Subject Categories : Helicopters
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE