Accession Number : AD0685396

Title :   ROUGH WALL TURBULENT BOUNDARY LAYERS.

Descriptive Note : Final rept. Sep 65-Jul 68,

Corporate Author : MELBOURNE UNIV PARKVILLE (AUSTRALIA) FLUID MECHANICS GROUP

Personal Author(s) : Perry,Anthony E. ; Schofield,William H. ; Joubert,Peter N.

Report Date : JUL 1968

Pagination or Media Count : 173

Abstract : The paper describes a detailed experimental study of turbulent boundary layer development over rough walls in both zero and adverse pressure gradients. Skin friction was determined by pressure tapping the roughness elements and measuring their form drag. Two wall roughness geometries were chosen each giving a different law of behaviour. However, it has been found that results for both types of roughness correlate with a Reynolds number based on wall shear velocity and on the distance below the crests of the elements from which the logarithmic distribution of velocity is measured. One important implication of this is that a zero pressure gradient boundary layer with a cavity type rough wall conforms to Rotta's condition of precise self preserving flow. (Author)

Descriptors :   (*TURBULENT BOUNDARY LAYER, *SURFACE ROUGHNESS), WALLS, PRESSURE, SKIN FRICTION, REYNOLDS NUMBER, SHEAR STRESSES, VELOCITY, TABLES(DATA), AUSTRALIA

Subject Categories : Aerodynamics
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE