A two color backscatter laser anemometer for determining spatial velocity correlations

A Laser Anemometer Optical System has been designed and constructed that will allow spatial correlations of velocity to be determined in confined flows where only a single, limited optical access exists. This work describes the modular, two component, backscatter optical system used for projecting two separable measurement volumes into a flow and collecting the light scattered from each without crosstalk. A simple substitution of optical modules is also described which allows the optical system to measure two orthogonal velocity components at a single point. The system has been specifically tailored to the study of flows in internal combustion engines.