Accession Number : AD0672963

Title :   FREE-MOLECULAR DRAG FOR FLOW ALONG A CONCAVE CYLINDRICAL SURFACE ORIENTED AT ARBITRARY ANGLES-OF-ATTACK,

Corporate Author : AEROSPACE CORP EL SEGUNDO CALIF EL SEGUNDO TECHNICAL OPERATIONS

Personal Author(s) : Stewart,J. Daniel

Report Date : MAY 1968

Pagination or Media Count : 78

Abstract : The local shear stresses and drag are determined for a concave cylindrical segment oriented at an angle of attack. The enclosed half-angle and angle of attack are varied from 0 to 90 deg and the flow velocity lies in the plane of symmetry. The gas particles are assumed to be diffusely reflected from the surface and completely accommodated to the wall temperature. No end-effects are included. A complete analysis of the effects of multiple surface collisions is given and the various components of drag are compared and discussed. Analytical solutions are obtained under the assumption of hyperthermal flow and the results are compared with the results of the analysis which includes all thermal motion. For sufficiently large values of the normal component of the speed ratio the simplified results for the hyperthermal case may be used. It is also found that the total drag is very nearly equal to the total drag for a flat plate with the same projected chord area, the difference being attributed to the reflected particles not having a cosine distribution when they cross the chord plane. (Author)

Descriptors :   (*RAREFIED GAS DYNAMICS, DRAG), CYLINDRICAL BODIES, SURFACES, ANGLE OF ATTACK, INTERACTIONS, FLAT PLATE MODELS, REFLECTIVITY, SHEAR STRESSES

Subject Categories : Aerodynamics
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE