Laser Beam Propagation Through Jet Exhausts

Abstract

CO2 (10.6 micron) and He-Ne (6328A) laser beams were passed through the highly turbulent region in the exhaust of a jet engine (J-57 with afterburner). Experimental information was obtained on the absorption, scattering and turbulence effects of the jet exhaust on both laser beams for various propagation paths. Estimates of a structure constant that would characterize the turbulence in the exhaust are made from the beam spread of focused and collimated beams. The structure constant obtained in this manner is then compared with the structure constant determined from scintillation measurements on the CO2 beam and with the results of hot-wire anemometer readings in the exhaust. The various methods yield results for the structure constant that are in good agreement.

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1970
Accession Number
AD0878493

Entities

People

  • Charles B. Hogge
  • Keith G. Gilbert
  • Walter L. Visinsky

Organizations

  • Air Force Research Laboratory

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Afterburners
  • Amplitude
  • Atmospheric Motion
  • Carbon Dioxide
  • Carbon Dioxide Lasers
  • Coefficients
  • Frequency
  • Gases
  • Hot Gases
  • Hot Wire
  • Hot Wire Anemometers
  • Intensity
  • Jet Engines
  • Laser Beams
  • Measurement
  • Radiation
  • Waves

Fields of Study

  • Physics

Readers

  • Fluid Mechanics and Fluid Dynamics.
  • Internal Combustion Engine (ICE) Technology.
  • Optical Physics and Photonics.

Technology Areas

  • Directed Energy