Yip - Development and Application of a High-Speed Three-Dimensional Density Measurement Technique for Aero-Optic Applications

Abstract

A density measurement technique based on the planar laser induced fluorescence (PLIF) of acetone vapor was developed and shown to be practical for 2-D density measurements in a high speed wind transonic wind tunnel. The random uncertainty in density measurements was estimated to be on the order of 8% without pixel binning and as low as 3% with pixel binning, thus showing that acetone PLIF is a viable technique for measurement of density in compressible flow fields. The technique was applied to visualize the shock induced separation and turbulent wake of a hemisphere mounted in a Mach 0.78 free stream. Density images clearly showed the presence of shock waves, a flapping wake structure and significant density drops within the cores of vortices formed in the separating free shear layer. The density drops could reach magnitudes up to 50% from the free stream value confirming that compressibility effects on density fluctuations within a weakly compressible shear layer are significant and cannot be explained through mixing models alone.

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Document Details

Document Type
Technical Report
Publication Date
Mar 25, 2011
Accession Number
ADA563707

Entities

People

  • Brian S Thurow

Organizations

  • Auburn University

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies
  • Ground and Sea Platforms
  • Sensors
  • Weapons Technologies

DTIC Thesaurus Topics

  • Boundary Layer
  • Chemical Oxygen Iodine Lasers
  • Computational Fluid Dynamics
  • Flow Visualization
  • Fluid Dynamics
  • Geometry
  • Hydrodynamics
  • Laser Induced Fluorescence
  • Lasers
  • Light Sources
  • Optics
  • Physics Laboratories
  • Pressure Measurement
  • Quantum Yields
  • Three Dimensional
  • Turbulent Mixing
  • Two Dimensional

Fields of Study

  • Physics

Readers

  • Combustion science or combustion engineering.
  • Fluid Mechanics and Fluid Dynamics.
  • Image Processing and Computer Vision.

Technology Areas

  • Directed Energy