Acoustic velocity profiler for laboratory and field studies

A monostatic acoustic Doppler velocity profiler (ADVP) for use in hydraulic research is presented including signal treatment algorithms. The 1-MHz ADVP used in the present study has an accuracy better than 2 mm.s(-1) with a range of up to 100 cm for velocities up to 290 cm.s(-1) and a resolution of 256 points in the profile. Results of ADVP measurements in uniform flow in two laboratory open channels with smooth and gravel beds compare favorably with established distribution laws for mean velocity, variance, and Reynold's stress, indicating that the turbulence scales are sufficiently resolved by the instrument. Measurements with the same instrument in a river and a lake illustrate that it is capable of producing excellent results in the field as well. It was demonstrated that, unaffected by water quality, the instrument is a good research tool for nonintrusive and accurate instantaneous profile measurements under turbulent flow conditions.