Doppler Flowmeter

This is a picture of the Doppler Flowmeter in a Test Flume. Water is pumped through the flume by a 2 foot propeller blade driven by a 5 HP motor. The flume baffle opening is partly visible on the right. The motor RPM rate is varied by a controller in order to be able to test the flowmeter at various flow rates.

One of the cylinders contains a high-frequency transmiiter, while the other contains a receiver that detects the signal that is reflected from acoustic reverberations from discontinuities (bubbles and particles) within the intersection volume of the two beams in front of the housing. This separation greatly reduces the flow errors produced by the housing. The beamwidths are approximately the size of a dime, so the reverberation volume is quite small. This results in a one-dimensional velocity vector measurement of the flow at a point in front of the unit. A 3-vector instrument was proposed for measuring the three velocity space vector components, but it was never built.

There were two technical papers written about this system. The first paper was written in conjunction with the University of Miami Marine Laboratory.