Dynamics of particles and bubbles in water and viscoplastic flow mixtures

由于全球需求，加拿大的采矿和油砂行业已经扩大。然而，现有的采矿和油砂活动需要在矿石开采和选矿过程中消耗大量的水。水中的悬浮物呈非牛顿粘塑性流动。此外，大多数实验研究都是在静止环境中进行的，而海洋、湖泊、尾矿池和自然溪流中含有背景湍流，这是以前的研究中没有考虑的。需要有效的颗粒混合和分离机制，以最大限度地减少采矿活动和淡水摄取的足迹。这可以通过更好地了解湍流水和粘塑性流动环境中的颗粒动力学来实现。加拿大城市人口大幅增加，导致对淡水和废水处理的需求增加，这可以通过提高水质来解决。许多采矿和环境过程也使用非牛顿流体中的空气喷射。拟议的研究计划将侧重于在背景湍流存在的情况下含沙射流、颗粒云和气泡射流/羽流的流体动力学，并将研究固体物体、颗粒和气泡在粘塑性环境混合物中的运动。了解气泡或沙粒与环境水的动态相互作用对于工程系统的合理设计和优化具有重要意义。这一现象的复杂性以及在理解喷嘴尺寸、颗粒尺寸、释放高度和喷嘴角度等控制参数的影响方面的挑战，需要考虑实验和数值方法。NSERC-Discovery计划由四个项目组成，其目标是进行标度分析，确定喷嘴直径、颗粒尺寸、释放高度、释放角度和颗粒云运动的重要参数；测试和表征非牛顿流体混合物的流变性，如屈服应力和表观粘度；确定通过减小气泡尺寸和气泡速度来改善氧气传递的机理；根据标度分析确定喷嘴直径、喷嘴角度和气流流量，并测试气泡射流和羽流中的最佳气水流量比；确定粘塑性流动混合物中气泡羽流的流型分类；对固体物在静止环境水、受控背景湍流和粘塑性混合物中的运动进行数值模拟，对静止环境水中气泡射流的运动进行验证试验，并研究相邻两个成角度的气泡射流中的气泡破碎和合并。拟议项目的结果将帮助加拿大人获得更多淡水，并使工业能够有效地回收和再利用水，用于其拟议模型的活动。

Mining and oil sand industries have been expanded in Canada due to the global need. However, existing mining and oil-sand activities require immense water consumption during ore extraction and mineral processing. The concentrated suspended minerals in water behave like non-Newtonian viscoplastic flow. In addition, most experimental studies were performed in stagnant ambient whereas ocean, lakes, tailing ponds, and natural streams contain background turbulence, which was not considered in previous studies. Efficient particle mixing and separation mechanisms are needed to minimize the footprint of mining activities and freshwater intake. This can be achieved by better understanding of particle dynamics in turbulent water and viscoplastic flow ambient. Urban populations in Canada have greatly increased, resulting in increased demand for fresh water and wastewater treatment, which can be addressed by enhancing water quality. Many mining and environmental processes use air injections in non-Newtonian fluids as well. The proposed research program will focus on the hydrodynamics of sediment-laden jets, particle clouds, and bubbly jets/plumes in the presence of background turbulence, and will investigate the motion of solid objects, particles, and bubbles in viscoplastic ambient mixtures. Understanding the dynamic interactions of air bubbles or sand particles with the ambient water is important for proper design and optimization of engineering systems. The complexity of the phenomenon and the challenge in understanding the effects of controlling parameters such as nozzle size, particle size, release height, and angle of nozzles requires considering both experimental and numerical approaches. The proposed NSERC-Discovery program consists of four projects, the goals of which are to perform scaling analysis and identify important parameters such as nozzle diameter, particle size, release height, release angle, and particle size distribution on the motion of particle clouds; to test and characterize the rheology of non-Newtonian fluid mixtures such as yield stress and apparent viscosity; to identify the mechanisms that improve oxygen transfer by reducing bubble size and bubble velocity; to determine nozzle diameter, nozzle angle, and airflow discharge based on the scaling analysis, and test the optimum air-water discharge ratio in bubbly jets and plumes; to determine the regime classification of bubble plumes in viscoplastic flow mixtures; to perform numerical simulation on the motion of solid objects in stagnant ambient water, controlled background turbulence, and viscoplastic mixtures and to conduct validation tests on the motion of bubbly jets in stagnant ambient water and investigate bubble breakup and coalescence in two adjacent bubbly jets with an angle. The outcomes of the proposed program will help Canadians to secure more fresh water and enable industries to efficiently reclaim and reuse water for their activities with the proposed models.