Graduate Research Training in Advanced Diagnostics Techniques (AASERT)

Abstract

Tunable diode laser absorption probes have been developed for characterization of short-duration hypersonic flows produced in shock tunnels and expansion tubes. A new single-wavelength probe was tested in a large reflected shock tunnel at Calspan and in an expansion tube at Stanford. The demonstrated success of this sensor in characterizing the time evolution of freestream velocity should improve the utility of aerodynamic test data obtained in high-enthalpy hypersonic tunnels and should also provide a means of monitoring the effects of facility modifications aimed at increasing test time and flow steadiness. Good agreement was found over the full range of velocities observed (up to 5.0 km/sec) when the water vapor and potassium probes were employed simultaneously. Infrared PLIF imaging techniques have been developed for imaging of CO and CO2 in flames. These diagnostics employ tunable optical parametric oscillators or high-pulse-energy gas lasers in the infrared to excite vibrational transitions in molecules, and use infrared cameras to image vibrational (infrared) fluorescence. These techniques have been demonstrated in flows ranging from mom-temperature mixing to laminar diffusion flames.

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Document Details

Document Type
Technical Report
Publication Date
Oct 14, 2000
Accession Number
ADA383896

Entities

People

  • Ronald Kenneth Hanson

Organizations

  • Stanford University

Tags

Communities of Interest

  • Advanced Electronics
  • Air Platforms
  • Sensors

DTIC Thesaurus Topics

  • Combustion
  • Detection
  • Detectors
  • Engineering
  • Fluorescence
  • Gas Lasers
  • Imaging Techniques
  • Infrared Cameras
  • Laser Induced Fluorescence
  • Lasers
  • Mechanical Engineering
  • Monitoring
  • Propulsion Systems
  • Shock Tunnels
  • Students
  • Test Facilities
  • Tubes

Fields of Study

  • Physics

Readers

  • Combustion science or combustion engineering.
  • Fluid Mechanics and Fluid Dynamics.
  • Molecular Photonics/Laser Physics

Technology Areas

  • Directed Energy
  • Directed Energy - Lasers
  • Hypersonics
  • Hypersonics - Hypersonic Flight
  • Hypersonics - Hypersonic Flow