Development of an instantaneous velocity-vector-profile method using conventional ultrasonic transducers

Abstract

Abstract A velocity vector profile technique based on an ultrasound pulsed Doppler method can enrich the information on the flow field. However, it has shown low availability because a new design of special transducers is required for each measurement case. This study proposes a new method of profiling the velocity vectors using conventional ultrasound transducers that are widely supplied to ultrasound velocity profile users. We constructed a configuration of transducers to minimize the uncertainty of the detection points at the receivers, and a measurable distance was theoretically determined by the configuration. Two feasibility tests were carried out. One was a test for the assessment of the measurable distance, which agreed well with the theoretical distance. The other was the evaluation of the measurement of 2D velocity vectors by the new method, and it was performed in a towing tank facility without the velocity fluctuation. From the evaluation, it was confirmed that the measured vectors showed good agreement with the reference values, and their accuracy and precision were competitive compared to previous studies. In order to demonstrate this, the developed method was applied to two unsteady flows. The results clarified that the proposed method guarantees high availability and accuracy for the velocity vector profiles.