Corrections to Fringe Distortion Due to Flow Density Gradients in Optical Interferometry

Abstract

An analytical method is formulated to account for distortions of optical interferograms used for studies of flow over airfoils experiencing dynamic stall. It is shown that such distortions are generated primarily due to optical path deflections in the test flow, caused by large density gradients. Such in-flow optical path deflections are neglected in conventional optical techniques for flow studies. The present method employs a ray analysis to determine these in-flow optical path deflections, and accurately predicts the interferogram distortions.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1993
Accession Number
ADA268650

Entities

People

  • L. W. Carr
  • M. S. Chandrasekhara
  • Y. C. Cho

Organizations

  • National Aeronautics and Space Administration

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Aeronautics
  • Compressible Flow
  • Computational Fluid Dynamics
  • Deflection
  • Diffraction
  • Displacement
  • Distortion
  • Flow
  • Fluid Dynamics
  • Fluid Mechanics
  • Free Stream
  • Interferograms
  • Interferometry
  • Leading Edges
  • Mach Number
  • Refraction
  • Refractive Index

Fields of Study

  • Physics

Readers

  • Aerodynamics.
  • Optical Physics and Photonics.