In this paper, a novel velocimeter based on laser self-mixing Doppler technology has been developed for speed measurement. The laser employed in our experiment is a distributed feedback (DFB) fiber laser, which is an all-fiber structure using only one Fiber Bragg Grating to realize optical feedback and wavelength selection. Self-mixing interference for optical velocity sensing is experimentally...

We report on experiments on the effects of air bubbles on ultrasound velocity measurements in fluids. We used an acoustic Doppler velocimeter system for measuring the three velocity components in a single point and an acoustic Doppler velocimetry profiler system for measuring axial velocity in several points along the beam. The results suggest that both systems essentially measure the velocity ...

patterns in blood vessels with the directional ultrasonic Doppler technique through a transcutaneous approach. Jap Circ J 37: 735, 1973 37. Kalmanson D, Aigueperse J, Veyrat C, Cornec C, Chiche P: Noninvasive technique for diagnosing congenital and acquired ventricular septal defects using directional Doppler ultrasound. Correlations with phasic flow velocity patterns of the shunt. Br Heart J 3...

The effect of a combined system of the bed suction and jet injection as a pier-scour countermeasure on the turbulent flow field is studied in a laboratory flume using an Acoustic Doppler Velocimeter (ADV). The three components of the velocities in the vertical symmetry plane in the equilibrium scour hole in front and rear of the pier under 3-jet injections and bed suction rate Qs/Q0 = 2%located...

the effect of a combined system of the bed suction and jet injection as a pier-scour countermeasure on the turbulent flow field is studied in a laboratory flume using an acoustic doppler velocimeter (adv). the three components of the velocities in the vertical symmetry plane in the equilibrium scour hole in front and rear of the pier under 3-jet injections and bed suction rate qs/q0 = 2%located...

An industrial laser Doppler velocimeter has been developed for accurately measuring the velocity and length of moving surfaces. The instrument's advanced optical and electronic design provides a large depth of field, high SNR, and large dynamic range making it very suitable to industrial process control applications.

In this article we present a novel optical sensor allowing simultaneous measurements of axial position and tangential velocity of moving solid state objects. An extended laser Doppler velocimeter setup is used where two interference fringe systems are superposed slightly tilted. The axial position of moving solid state surfaces is determined via a phase evaluation. The phase laser Doppler dista...