Unsteady Boundary Layers with an Intelligent Numerical Scheme.

Abstract

A numerical method has been developed to represent unsteady boundary layers with large flow reversal. It makes use of the characteristic box scheme which examines the finite-difference grid in relation to the magnitude and direction of local velocity and reaches and implements a decision to ensure that the Raetz principle of regions of influence and dependence is not violated. The method has been applied to the problem of an impulsively started circular cylinder and the results though generally consistent with those of van Dommelen and Shen obtained with a Lagrangian method, show some differences. The time step is identified as very important and, with the present intelligent numerical scheme, the results were readily extended to times far beyond those previously achieved with Eulerian methods. Extrapolation of the results suggests that the much discussed singularity for this unsteady flow is the same as that of the corresponding steady flow.

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1984
Accession Number
ADA179706

Entities

People

  • Tuncer Cebeci

Organizations

  • Douglas

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Aircrafts
  • Boundary Layer
  • Boundary Layer Flow
  • Boundary Value Problems
  • Difference Equations
  • Differential Equations
  • Equations
  • Flow
  • Fluid Dynamics
  • Laminar Boundary Layer
  • Layers
  • Skin Friction
  • Steady Flow
  • Steady State
  • Turbulent Flow
  • Turbulent Mixing
  • Unsteady Flow

Readers

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