SPECTRAL ANALYSIS OF THE SIGNAL FROM THE LASER DOPPLER VELOCIMETER TURBULENT FLOWS

The power spectrum of phototube current from a Laser Doppler Velocimeter operating in the heterodyne mode has been computed. The spectrum is obtained in terms of the space time correlation function, for turbulent flow of the fluid. The spectral width and shape predicted by the theory is in agreement with experiment. For normal operating parameters the time average spectrum contains information only for times shorter than the Lagrangian integral time scale of the turbulence. To examine the long time behavior one must use either extremely small scattering angles much longer wavelength radiation or a different mode of signal analysis, e.g., F.M. detection.

• Corporate Authors:

  Case Western Reserve University

  Chemical Engineering Division
  Cleveland, OH  United States  44106
• Authors:
  • Edwards, R V
  • Angus, J C
  • Dunning Jr, J W
• Publication Date: 1972-3-28

Media Info

• Pagination: 24 p.

Subject/Index Terms

• TRT Terms: Flow measurement; Power; Power spectra; Spectrum analysis; Turbulence; Velocity
• Old TRIS Terms: Velocity fluctuations
• Subject Areas: Design; Energy; Marine Transportation;

Filing Info

• Accession Number: 00035670
• Record Type: Publication
• Source Agency: National Technical Information Service
• Contract Numbers: N00014-67-A-04040008
• Files: TRIS
• Created Date: Oct 27 1973 12:00AM