Search for Chaos in Free Shear Flows

Abstract

Theoretical studies on the temporal and spatial structure in blunt- body wakes have revealed the necessary conditions under which global, self- sustained oscillations appear and have provided firm criteria for specifying the frequency of these oscillations. The theory has also been employed to describe the preferred mode in jets. The two-dimensional structure of these modes provides a firm basis for describing the spatial structure of the vortex pattern observed in wakes. In addition, a theoretical description of the appearance of the spatial chaos in wake-shear layers, and its representation in terms of a one-dimensional map, has been provided. An experimental facility and necessary instrumentation have been assembled and experiments are in progress on spatial chaos in wake-shear layers. Experimental results have revealed a parameter domain where a temporal vacillation occurs between the Karman mode and the shear layer mode. Interesting results with possible application to thrust-vectoring of base flows have also been identified

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 1992
Accession Number
ADA266245

Entities

People

  • Chih-ming Ho
  • Larry G. Redekopp
  • Patrick Huerre

Organizations

  • University of Southern California

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies
  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Air Force
  • Air Force Facilities
  • Aspect Ratio
  • Bodies
  • Boundaries
  • Boundary Layer
  • California
  • Classification
  • Flow
  • Fluid Flow
  • Frequency
  • Layers
  • Reynolds Number
  • Shear Flow
  • Turbulent Mixing
  • Two Dimensional
  • Universities

Fields of Study

  • Physics

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Theoretical Analysis.
  • Wave Propagation and Nonlinear Chaotic Dynamics.