Abstract

Grating anemometry is an optical technique able to perform local measurements of large particle velocity in dispersed two-phase flows. It was first proposed by Semiat and Dukler who assumed the standard LDA formula to be valid. A theoretical model is derived to (i) predict the exact relation between the frequency of the collected signal and the particle velocity, and (ii) maximize the signal strength and modulation depth by computing the intensity distribution vs the particle radius and trajectory. Shortcomings of the standard formula are given for a bubble as well as the kind of velocity measured. Such calculations are necessary to define a new grating anemometer operating in an endoscopic mode.

© 1986 Optical Society of America

Local velocity and size measurements of particles in dense suspensions: theory and design of endoscopic grating velocimeter–granulometers

A. Cartellier
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