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波的速度测量技术更好地了解致密固液悬浮液的流动物理特性。致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。我们在理解上的差距部分是由于它们的不透明性，这使我们无法使用传统的光学测量技术来详细研究它们。这些流体广泛存在于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、可再生能源和制药工艺。最近，清洁能源开发商RheEnergise发明了一种高密度水电（HDH）技术，通过使用一种专门的高密度悬浮流体来提升抽水蓄能系统。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。我们提出的研究旨在充分表征密集悬浮液的流动特征，以便对高密度水电系统的各种组件进行优化设计，如泵、涡轮机、阀门和不同的管道和配件。我们将使用超声图像测速和回波拉格朗日南粒子跟踪来研究分散颗粒（悬浮固体颗粒）和载体流体颗粒的相互作用，以揭示这些密集悬浮液的流动物理。本研究获得的实验结果将在推导不同流动条件和几何形状下致密悬浮液湍流的新模型以及验证计算机模型方面发挥关键作用。此外，我们的目标是改进超声图像测速技术，以推动该技术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密集悬浮液的流体流动，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.