Water Tunnel Flow Visualisation of Vortex Breakdown Over the F/A-18

Abstract

Vortex flow patterns over models of the F/A-18 aircraft were visualised using dye and hydrogen bubble techniques in a water tunnel. The axial position of vortex breakdown in the leading-edge extension (LEX) vortices was measured, and was found to be insensitive to Reynolds number, to flap setting, and to small variations in model cross section shape. Engine inlet flow did alter the vortex breakdown position, at flow rates that might be encountered under flight conditions. The fitting of fences on the LEX upper surface did not affect the axial position of vortex breakdown, but did alter the vortex structure. These alterations were examined in some detail.

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1990
Accession Number
ADA236026

Entities

People

  • D. H. Thompson

Tags

Communities of Interest

  • Air Platforms
  • Space

DTIC Thesaurus Topics

  • Aerodynamic Configurations
  • Aircrafts
  • Cameras
  • Cross Flow
  • Delta Wings
  • Flow Rate
  • Flow Visualization
  • Fluid Mechanics
  • Leading Edge Flaps
  • Leading Edges
  • Measurement
  • Mechanics
  • Reynolds Number
  • Test Facilities
  • Water Tunnels
  • Wind Tunnel Tests
  • Wind Tunnels

Fields of Study

  • Physics

Readers

  • Fluid Mechanics and Fluid Dynamics.