Nonintrusive Method to Compute Water Discharge in Pipes with a Low Depth-to-Diameter Ratio Using Ultrasonic Doppler Velocimetry

Abstract

AbstractA nonintrusive method to calculate water depth and discharge in partially full pipes using data from a single ultrasonic Doppler velocimeter (UDV) profiler is presented. The position of the free surface is identified from the velocity profiles measured with the UDV. The flow discharge is computed from an approximated parameterization of the velocity field in the cross-section, using a single measured velocity profile. The proposed methodology was applied to steady and unsteady flow conditions in two different pipes with diameters of 90 and 200 mm, and depth-to-diameter ratios up to 0.35. Under these conditions, the water depth and discharge were measured with mean absolute errors of 1 mm and 0.1 L/s in the 90-mm pipe and 0.5 mm and 0.05 L/s in the 200-mm pipe. These errors are almost independent of the discharge.