Vortex System Evolution in 2- and 3-D Swept Trailing Edge Flows

Abstract

Instability wavefront orientation and vortex system interaction were studied in a swept-trailing-edge mixing layer and in a slanted nozzle jet flowfield at low subsonic velocities. Flow visualization and image processing, and hot-wire data comprised the main body of experimental observations. The response of full-span wave systems of swept and unswept orientation were documented as a function of acoustic excitation introduced through a thin slot at the trailing edge. The lateral spreading of a wave system with only partial- span excitation was shown to be asymmetrical in a swept mixing layer. The jet flowfield was studied using a simultaneous axial and transverse laser sheet illumination. Excitation frequency-and amplitude-dependence of instability wave system orientation was characterized. Digitized flow visualization images were decomposed to show the axial and helical shear layer modes.

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Document Details

Document Type
Technical Report
Publication Date
Jul 24, 1990
Accession Number
ADA232692

Entities

People

  • David E. Parekh
  • Frederick W. Roos
  • Jerome T. Kegelman
  • Richard W. Wlezien
  • Valdis Kibens

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Air Force
  • Amplitude
  • Boundary Layer
  • Excitation
  • Flow
  • Flow Visualization
  • Fluid Mechanics
  • Frequency
  • Geometry
  • Hot Wire
  • Image Processing
  • Light Sources
  • Orientation (Direction)
  • Three Dimensional
  • Trailing Edges
  • Transverse
  • Turbulent Mixing

Fields of Study

  • Physics

Readers

  • Fluid Mechanics and Fluid Dynamics.

Technology Areas

  • Directed Energy