Contactless three=dimensional flow velocimetry method for multiple light section

摘要

The method involves using an optical system (8) with a beam-splitter (11) on its optical axis in front of two photodetectors (9,10), e.g. high spatial resolution video chips, behind polarisation filters (12,13). Polarised beams (3,4) from a pulsed laser (1) are confined by another optical system (2) to irradiate two flat partial volumes (5,6). Tracer particles (7) are injected into the flat partial vols. and are lit by the pulsed beams. The fluid velocity is deduced from a local autocorrelation function of a double exposure of either vol., a local cross-correlation function of two separate images of the same vol., and a local cross-correlation function of images of both vols..