MATHEMATICAL THEORY OF TURBULENCE. PART I. ASYMPTOTIC EXPANSIONS IN WALL-LAW LAYER

Abstract

In the case of a linear differential equation an expansion in powers of a parameter may be multiplied by any power of that parameter and still be a solution of the differential equation. In general, this is not so in the case of non-linear differential equations. In the present paper this fact is exploited to derive possible asymptotic expansions compatible with Navier-Stokes equations in wall-law layer of stationary turbulent flows, i.e. turbulent flows in which all properly averaged quantities remain stationary. Three types of stationary turbulent flow are considered, (i) the flow between two parallel plane walls in relative motion, (ii) pressure flow between parallel plane walls at rest, and (iii) boundary layer along a flat plate. It is found that two essentially different asymptotic expansions are compatible with Navier-Stokes equations. One of these expansions may yield the above wall law whereas the other yields a possible wall law which indicates the possibility of a type of m that found in ordinary laboratory experiments. In either case the differential equations are the same in all three types of flow considered, thus indicating the same wall law in all three cases. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jul 01, 1960
Accession Number
AD0257176

Entities

People

  • Oddvar Bjorgum

Organizations

  • University of Bergen

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Asymptotic Series
  • Boundary Layer
  • Differential Equations
  • Equations
  • Flow
  • Layers
  • Linear Differential Equations
  • Navier Stokes Equations
  • Relative Motion
  • Stationary
  • Turbulent Flow

Readers

  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)
  • Fluid Mechanics and Fluid Dynamics.