Accession Number : AD0734156

Title :   Singular Perturbation and Turbulent Shear Flow near Walls.

Descriptive Note : Technical rept.,

Corporate Author : PURDUE UNIV LAFAYETTE IND PROJECT SQUID HEADQUARTERS

Personal Author(s) : Fendell,Francis E.

Report Date : NOV 1971

Pagination or Media Count : 60

Abstract : The method of matched asymptotic expansions is applied to fully turbulent shear flow near walls in the limit of an appropriately defined Reynolds number tending to infinity. In particular, turbulent pipe/channel flow and boundary-layer flow on a flat plate with an external pressure gradient upstream of any separation is examined. The relevant Reynolds number is the ratio of the turbulent stress to the Newtonian stress. For the postulated expansions, the logarithmic profile, wall friction law, and classical similarity results are deduced without an explicit closure condition relating theturbulent stress to the Newtonian stress. Continuation to higher order is shown to be in general indeterminate without additional physical input to the formulation. (Author)

Descriptors :   (*TURBULENCE, MATHEMATICAL MODELS), WALLS, PERTURBATION THEORY, SHEAR STRESSES, TURBULENT BOUNDARY LAYER, PIPES, FLAT PLATE MODELS, ASYMPTOTIC SERIES, PRESSURE

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE