LASER DOPPLER ANEMOMETRY

Abstract

THE PROBLEM OF THE CONTINUOUS DETECTION OF THE DOPPLER FREQUENCY IN ORDER TO OBTAIN AN ANALOGICAL REPRESENTATION OF THE SPEED OF SMALL PARTICLES IN SUSPENSION IN A FLUID, AND CONSEQUENTLY THE SPEED OF THE LATTER, AS WELL AS THE DESIGN OF A FREQUENCY DETECTOR ARE DISCUSSED.THE FREQUENCY DETECTOR ALLOWS TURBULENT SPEED VARIATIONS TO BE MEASURED, WHICH IS DEMONSTRATED BY MEASUREMENT OF THE OSCILLATORY FLOW PRODUCED BY EXTENSIONS OF VORTICES.IT IS SUGGESTED THAT, ON THE BASIS OF PRACTICAL EXPERIENCE GAINED BY THE USE OF LASER ANEMOMETRY IN THE STUDY OF WATER AND AIR FLOWS, NEW APPLICATIONS ARISE FOR THIS MEASUREMENT TECHNIQUE FOR WHICH HOT WIRE AND HOT FILM ANEMOMETERS ARE UNSUITABLE.(BASED ON AUTHORS' SUMMARY)