Accession Number : AD0773183

Title :   Relations Between Solutions of the Navier-Stokes Equations and of the Boundary Layer Equation,


Personal Author(s) : Guderley,Karl G. ; Wen,Shih-Liang

Report Date : NOV 1973

Pagination or Media Count : 65

Abstract : The relations between solutions of the full Navier-Stokes equations and of the boundary layer equations are explored by a discussion of the eigensolutions of a model equation which retains the essential features of the problem. Important are the following results. The system of eigensolutions for the full Navier-Stokes equations is not well suited to represent numerically the concentration of vorticity occurring in the boundary layer. Restriction of the viscosity effect to a layer close to the wall is therefore desirable from a numerical point of view. With this provision the boundary layer equation, including a subsequent correction for its displacement thickness, reproduces perturbations of the Navier-Stokes equations which correspond to potential flow solutions (with wall corrections) and to vorticity effects propagating downstream. The Navier-Stokes equations allow for effects propagating upstream; they are confined to a narrow layer close to the wall within the boundary layer and die out very quickly. In the vicinity of a separation point these solutions gain greater importance. (Author)

Descriptors :   *Boundary layer flow, *Navier Stokes equations, *Vortices, Two dimensional flow, Incompressible flow, Partial differential equations, Numerical integration

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE