Experimental investigation of the flow of dense solid-liquid suspensions using echo-PIV and echo-LPT

本研究的目的是利用基于超声的速度测量技术来更好地了解稠密固液悬浮液的流动物理。稠密悬浮液是一种复杂的流体，其在湍流状态下的行为尚不完全清楚。我们理解中的这种差距部分是由于它们的不透明性，这使得我们无法使用传统的光学测量技术来详细研究它们。这些流体存在于广泛的工业应用和环境问题中，如沉积物输送、雪崩、泥浆、火山碎屑流、可再生能源和制药过程。最近，清洁能源开发商RheEnergise发明了一种高密度水力(HDH)技术，通过使用专门的稠密悬浮液来增强抽水蓄能系统。这项技术与可再生能源相结合，可以帮助实现能源系统的脱碳，以防止剧烈的气候变化。我们拟议的研究旨在全面描述稠密悬浮液的流动特性，以便对高密度水力系统的各种部件进行优化设计，如泵、水轮机、阀门以及不同的管道和配件。我们将使用超声图像测速仪和回声拉格朗日颗粒跟踪来研究分散颗粒(悬浮固体颗粒)与载体流体颗粒的相互作用，以揭示这些稠密悬浮液的流动物理。本文的实验结果将对建立不同流动条件和几何形状下的稠密悬浮体湍流流动的新模型以及验证计算机模型起到关键作用。此外，我们的目标是改进超声图像测速技术，以便将该技术推向更高的雷诺数和更复杂的流体流动。这将包括开发一种基于超声波的速度测量方法，使我们能够测量固体表面附近稠密悬浮液的流体流动，这是目前具有挑战性的。

The goal of this research is to better understand the flow physics of dense solid-liquid suspensions using an Ultrasound-based velocity measurement technique. Dense suspensions are complex fluids whose behaviour in the turbulent state is not fully understood. This gap in our understanding is partially due to their opaqueness, which prevents us from using conventional optic measurement techniques to study them in detail. These fluids are present in a wide range of industrial applications and environmental problems such as sediment transport, avalanches, slurries, pyroclastic flows, renewable energy and pharmaceutical processes. Recently RheEnergise, a clean energy developer, has invented a High-Density Hydro (HDH) technology, which boosts pumped hydro storage system by using a specialized dense suspension fluid. This technology paired with renewable energy sources can help move towards decarbonizing energy systems to prevent dramatic climate change. Our proposed research is aimed at fully characterizing the flow features of dense suspensions to allow for the optimized design of various components of the High-Density Hydro system such as pumps, turbines, valves, and different pipes and fittings. We will use Ultrasound Image Velocimetry and echo Lagranginan Particle Tracking to investigate the interaction of dispersed particles (suspended solid particles) and carrier fluid particles to uncover the flow physics of these dense suspensions. The experimental results obtained in this investigation will play a key role in deriving novel models for the turbulent flow of dense suspensions under different flow conditions and geometries, as well as for validating computer models. Furthermore, we aim to improve the Ultrasound Image Velocimetry technique so as to push this technique to higher Reynolds numbers and more complex fluid flows. This will include developing an Ultrasound-based velocity measurement method that allows us to measure the fluid flow of dense suspensions near solid surfaces, which is currently challenging.