Computational Aspects of Unsteady Flows,

Abstract

This paper is concerned with the calculation of unsteady flows and particular with the development of numerical methods for solving unsteady boundary-layer equations and their application to the flows around practically important configurations such as oscillating airfoils. It provides a brief review of recent work and emphasizes the need for numerical methods which can overcome possible problems associated with flow reversal and separation. The ziz-zag and characteristics box schemes are described in this context and, when embodied in a method which permits interaction between solutions of inviscid and viscous equations, the characteristic box scheme is shown to avoid the singularly associated with boundary-layer equations and prescribed pressure gradient. Calculations have been performed for a cylinder started impulsively from rest and oscillating airfoils and the results are presented and discussed. It is concluded, for example, that turbulence methods based on an algebraic specification of eddy viscosity can be adequate, that location of transition is important to the calculation of the location of flow separation and, therefore, to the overall lift of an oscillating airfoil.

Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1985
Accession Number
ADP005014

Entities

People

  • A. A. Khattab
  • L. W. Carr
  • S. M. Schimke
  • Tuncer Cebeci

Organizations

  • Douglas

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Aerodynamics
  • Boundary Layer
  • Equations
  • Flow
  • Flow Separation
  • Fluid Dynamics
  • Fluid Flow
  • Fluid Mechanics
  • Layers
  • Mechanical Properties
  • Mechanics
  • Pressure Gradients
  • Unsteady Aerodynamics
  • Unsteady Flow

Fields of Study

  • Physics

Readers

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