Accession Number : ADP008933

Title :   Spectral Analysis of Turbulent Flows from LDA Measurements,

Corporate Author : TRINITY COLL DUBLIN (IRELAND)

Personal Author(s) : McDonnell, C. ; Fitzpatrick, J. A.

Report Date : 23 JUL 1992

Pagination or Media Count : 5

Abstract : Procedure for deriving the turbulence spectrum of a fluid flow from laser Doppler measurements are briefly reviewed. The flow in a small tube array is monitored using LDA measurements and the turbulence spectrum is calculated using both the correlation slotting technique and equal time sampling together with FFT based procedures. The letter is shown to give good results with considerable reduction in calculation time providing the sample rate is adequate. A comparison of the turbulence spectra for a flow in a heat exchanger array determined from both LDA and hot wire measurements indicates the limits of the procedures proposed.

Descriptors :   *TURBULENT FLOW, *LASER ANEMOMETERS, DOPPLER EFFECT, SPECTRUM ANALYSIS, FAST FOURIER TRANSFORMS, COMPARISON, HOT WIRE ANEMOMETERS, IRELAND.

Subject Categories : Fluid Mechanics
      Computer Programming and Software
      Optical Detection and Detectors
      Lasers and Masers
      Test Facilities, Equipment and Methods

Distribution Statement : APPROVED FOR PUBLIC RELEASE