New Laser Doppler Sensors for Spatial Velocity Information

Abstract

Laser Doppler Anemometry (LDA) is a non-intrusive method to measure velocities in fluid flows, often with the aim to determine the velocity profile for a given fluid. As other methods common LDA techniques rely on measuring the velocity in a small probe volume and then varying its position in the test section. The spatial resolution of such velocity profile is limited in principal by the size of the probe volume (say 1 mm). The new methlod and its variations allow improvements of the spatial resolutiion by at least one order of magnitude and to measure a small scale velocity profile while leaving the measuring apparatus fixed