Optical Methods for Data Processing in Heat and Fluid Flow

2

Application of Laser Doppler Anemometry and Infrared Thermograph Methods for Measurements of Fluid Flow in a Small Transonic Channel

R Dizene, E Dorignac, R Leblanc, and J M Charbonnier

Abstract

This Chapter presents a comparison of laser Doppler anemometer and Pitot-static sensing techniques for the measurement of the mean velocity and the turbulence properties in flows in a small transonic channel. The work deals with turbine blade cooling. The measurements have been done in a turbulent boundary layer which develops in jets/cross flow interaction. Comparison of precision measurement results between the two methods were made by conducting a series of tests and experiments, where the influence of the seeding over the measurements was shown. The mean and standard deviation estimated from the data are subject to both systematic and statistical uncertainty, and an analysis of these uncertainties is given. Another method of optical processing was investigated and used for stationary measurements of the temperature and the heat flux densities. This method consists of an application of an infrared thermograph technique. Conclusions are presented by the analysis of comparison results of wall temperature measurements with those taken from located thermocouples sensing.

Notation

D	injection tubes diameter (mm)
R	blowing rate ratio
Re	reynolds number
u, v	longitudinal and vertical ...