Ultrasound velocity profile (UVP) measurements in shallow open-channel flows

Abstract

This paper is concerned with velocity measurements in shallow water flows by using Ultrasonic Velocity Profile (UVP) probes. The measurements were made in a 10 m long, 0.4 m wide flume whose slope is 0.00117. Diagonal and horizontal positioning of a single probe and the combination of two probes were tested as configurations of the UVP probes. Streamwise and transverse velocities were obtained. A sensitivity analysis was performed to UVP parameters, namely to the distance of the window for each measurement and to the distance between each measuring point. The influence of four different seeding materials was also assessed. Filters for eliminating noise and spikes were applied. For 1D measurements, UVP streamwise velocities were compared with Pitot tube measurements. For 2D measurements, streamwise velocities and turbulent intensities were compared with known laws. The results show the importance of i) setting optimal UVP parameters values, ii) of positioning adequately the UVP probes and iii) using appropriate seeding.