Influence of Solid Particle Parameters on the Sound Speed and Attenuation of Pulses in ADM

Abstract

Acoustic discharge measurement devices (ADM) based on transit time measurements are widely used to measure water flow rates in channels and closed conduits for hydropower applications. In addition to making velocity and discharge measurements, the ADM simultaneously records the speed of sound and the attenuation of the acoustic pulse through the water-sediment mixture. This information can be used to estimate characteristics of the suspension such as the volume fraction of the sediment. Such information is crucial in hydropower plants because of the negative effects solid particles can have on the equipment. In this work, the Atkinson-Kytömaa model for monodisperse particles is applied to analyze the effect of solid particles and other operating parameters on the sound speed and attenuation in water suspensions. This model has been selected because it is suitable for the interested range of applications. The model has been validated by measurements with different particle material (glass, quartz, calcium carbonate), size, size distribution, shape, and concentration. Moreover, the sensitivity of the model to the particle parameters has been investigated and the critical parameters for monitoring applications have been identified.