Study of the Origin of Three Dimensional Structures in Shear Flows through External Forcing

Abstract

Experiments on an externally forced free shear layer are performed which study the origin of three-dimensional structures and chaos in shear flows. Transition routes between the laminar two dimensional stages of shear flows and their final complex three dimensional stages are examined. Two avenues of investigation are pursued. First, the general idea of a multi-frequency route to chaos is examined which treats the shear flow as an open dynamical system. An attempt is made to apply concepts from nonlinear dynamics to these systems Secondly, a new approach to generating three-dimensional structures in shear flows which involves the creation of a spatial shear in the frequency of external perturbations is presented. In these experiments, a variety of vortex reconnection behaviors is observed at the discontinuity.

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Document Details

Document Type
Technical Report
Publication Date
Mar 25, 1990
Accession Number
ADA221923

Entities

People

  • Kevin L. Williams
  • M. Gharib

Organizations

  • University of California, San Diego

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Aerodynamic Characteristics
  • Boundary Layer
  • Computational Fluid Dynamics
  • Equations Of Motion
  • Flow Visualization
  • Fluid Dynamics
  • Fluid Flow
  • Fluid Mechanics
  • Mechanics
  • Nonlinear Dynamics
  • Power Spectra
  • Reynolds Number
  • Shear Flow
  • Three Dimensional
  • Turbulence
  • Turbulent Flow
  • Turbulent Mixing

Fields of Study

  • Physics

Readers

  • Computational Fluid Dynamics (CFD)
  • Fluid Dynamics.
  • Theoretical Analysis.