Fast quantitative processing of particle image velocimetry photographs by a whole-field filtering technique

A fast quantitative processing of particle image velocimetry photographs by a whole-field spatial filtering technique is described. Photographs are observed through a conventional filtering setup. This produces fringe patterned images with each fringe corresponding to a fixed value of one velocity component. These images are acquired with a CCD camera and digitally processed to retrieve the fringe centerline positions. The interpolation of these data provides the velocity value on a grid of regularly spaced points.Photographs taken from a Rayleigh-Bénard convective flow have been processed with this technique and with a previously reported point-by-point technique. Results from both techniques compare well.This work was supported by Diputación General de Aragón under Grant No. PCB6-90