Filtered Rayleigh Scattering Measurements in a Buoyant Flow Field

Abstract

Filtered Rayleigh Scattering (FRS) is a non-intrusive, laser-based flow characterization technique that consists of a narrow linewidth laser, a molecular absorption filter, and a high resolution camera behind the filter to record images. Gases of different species have different molecular scattering cross-sections that become apparent as they pass through the interrogating laser light source, and this difference is used to discriminate between the different gaseous components. This study focuses on the behavior of a buoyant helium jet exiting horizontally into ambient air, and more specifically this jet's tendency to form side lobes that are discharged from the core fluid under low flow rate conditions. This jet behavior is documented and examined with relation to Froude, Grashof, and Reynolds numbers, and the behavior patterns are noted.

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Document Details

Document Type
Technical Report
Publication Date
Mar 01, 2008
Accession Number
ADA478957

Entities

People

  • Steven M. Meents

Organizations

  • Air Force Institute of Technology

Tags

Communities of Interest

  • Energy and Power Technologies
  • Sensors
  • Weapons Technologies

DTIC Thesaurus Topics

  • Air Force
  • Cameras
  • Doppler Effect
  • Flow Visualization
  • Fluid Flow
  • Froude Number
  • High Resolution
  • Laser Beams
  • Lasers
  • Light Sources
  • Measurement
  • Optical Detectors
  • Optical Properties
  • Optics
  • Photographs
  • Rayleigh Scattering
  • Scattering

Fields of Study

  • Physics

Readers

  • Combustion and Flow Dynamics.
  • Fluid Mechanics and Fluid Dynamics.
  • Optical Physics and Photonics.

Technology Areas

  • Directed Energy
  • Directed Energy - Lasers