Design of a Computer Controlled Laser-Doppler Anemometer for Fluid Flow Measurements.

A special designed two-component, two color optical LDA-system is described which allows to measure two orthogonal velocity components of a gas flow simultaneously. The LDA-system is mounted on a three dimensional NC-controlled (XYZ)-traverse and by means of this the measuring point may accurately be positioned throughout every point in the exit plane of a test nozzle. The computer is utilized to process the stochastic and intermittent laser-Doppler-signals. Application of this LDA-system allows flow velocities extending from laminar flows to supersonic flows to be measured with highest achievable accuracy.