Ultrasonic Measurement Method for Transversal Component of Water Flow Velocity
A0119Kageyoshi Katakura Koden Electronics Co.,Ltd.
A0120Phonebanhdith Alain ISMRA, ENSI de CAEN, Institute des Sciencesde la Matiere et du Rayonnement
There are many ultrasonic methods for flow speed measurement. These
methods are grouped into two categories: reflection mode and
transmission mode configurations.
In the first category, ultrasound Doppler systems are used. In the
system, the velocity component along the beam axis is derived from the
observed frequency shift in back scattered sound wave. When
propagating media is pure, the back-scattered sound wave is very weak.
Therefore, these methods will not detect flow speed of pure water or
wide ocean flow.
In the second category, through transmission methods are used. In the
method, ultrasound wave propagates through the current flow not with
orthogonal direction to the flow direction but with an inclined
Two-way transmissions, one is toward downstream and other is toward
upstream, give two propagation delay times. Difference between the
two delay times provides the flow velocity component along the sound
This method provides water flow velocity component along the sound
propagation path. Therefore, when the flow direction is unknown, this
method will not show true current flow volume through the plane of the
We propose a method to measure flow velocity perpendicular to the
sound propagation path. Proposed method provides true current flow
volume regardless to the flow direction. This paper will show
detailed procedures of the method and some results taken from
experiment in river. .