Velocity Measurements in Wet Steam Flows by Laser Anemometry and Pitot Tube

Abstract

Velocities up to 200 m/s in condensing steam flows have been successfully measured using a laser Doppler anemometer, without artificial seeding. The performance of the system is described and results are compared with simultaneous pitot tube measurements. The discrepancy between the alternative methods used here for converting pitot pressure to velocity in subsonic wet flow becomes greater at higher speeds; extension of this work is discussed, with the objective of calibrating pitot tubes for use at high subsonic and low supersonic speeds encountered in low pressure turbines.