An Investigation of Compressible Flows over Open Cavities Including Shear Layer Thickness Effects.

Abstract

The mathematical modelling of the two dimensional compressible for over an open rectangular cavity is considered. The flow field is divided into three regions: (1) the two-dimensional compressible flow outside the cavity which is governed by a convective wave equation; (2) the two dimensional flow inside the cavity for which the mean flow is neglected and thus is governed by the wave equation; and (3) the shear layer spanning the cavity which is the major focus of the investigation. the work of Tam and Block is followed and a method for determining the discrete frequencies of shear layer oscillation is determined including shear layer thickness effects and assuming that the shear layer grows downstream. a line source placed at the trailing edge is used to model the trailing edge interaction process and the analysis of a shear layer excited by a reflected wave of arbitrary frequency is considered. Since the mean flow in the shear layer is nonuniform, standard stability procedures do not work. The nonparallel effects are assumed to be weak. The method of multiple scales is used to analyze the nonparallel stability of the shear layer. The stability characteristics of the shear layer are used in an equation developed by Tam and Block to predict discrete oscillation frequencies. The numerical methods for solving the equations are discussed. Originator-supplied keywords include: Open cavity flows; Nonparallel stability; and Multiple scales.

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Document Details

Document Type
Technical Report
Publication Date
Sep 10, 1984
Accession Number
ADA150086

Entities

People

  • S. G. Kelly

Organizations

  • University of Akron

Tags

Communities of Interest

  • Energy and Power Technologies
  • Materials and Manufacturing Processes
  • Weapons Technologies

DTIC Thesaurus Topics

  • Boundaries
  • Compressible Flow
  • Computational Fluid Dynamics
  • Computational Science
  • Differential Equations
  • Eigenvalues
  • Engineering
  • Equations
  • Experimental Data
  • Fluid Dynamics
  • Fluid Mechanics
  • Mathematical Analysis
  • Mechanical Engineering
  • Real Variables
  • Sound Pressure
  • Turbulent Mixing
  • Two Dimensional

Readers

  • Fluid Dynamics.
  • Fluid Mechanics and Fluid Dynamics.