Velocity measurements at high temperatures by ultrasound Doppler velocimetry using an acoustic wave guide

Ultrasound Doppler velocimetry (UDV) was used to measure flow velocities at temperatures up to 620(degrees)C. To overcome the thermal restriction of the ultrasonic transducers an acoustic wave guide was used. The acoustic wave guide and the piezoelectric element are combined in the form of an integrated sensor. This approach allowed the first successful application of the ultrasound Doppler technique in liquid metals at temperatures above 200(degrees)C. The feasibility of this integrated sensor concept was demonstrated in experiments with metallic melts. Measurements were performed in a PbBi bubbly flow and in CuSn.