Dynamics of particles and bubbles in water and viscoplastic flow mixtures

水和粘塑性流动混合物中颗粒和气泡的动力学

• 批准号: RGPIN-2022-04787
• 负责人: Azimi, AmirHossein
• 金额: $ 1.89万
• 依托单位: Lakehead University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=749298
• 关键词: Dynamics; particles; bubbles; water; viscoplastic

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.

由于全球需求，加拿大的采矿和油砂行业已经扩大了。但是，现有的采矿和石油活动需要在矿石提取和矿产加工期间进行大量的用水量。水中的集中悬浮矿物的行为像非牛顿粘塑料流一样行为。此外，大多数实验研究是在停滞的环境中进行的，而海洋，湖泊，尾部池塘和自然流则含有背景湍流，这在先前的研究中没有考虑。需要有效的颗粒混合和分离机制，以最大程度地减少采矿活动和淡水摄入的足迹。这可以通过更好地理解湍流水和粘膜流动环境中的粒子动力学来实现。加拿大的城市人口大大增加，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液中的空气注射。拟议的研究计划将集中在背景湍流的情况下，将重点放在含沉积物的喷气机，颗粒云和起泡的喷气机/羽流的水动力上，并将研究粘性环境混合物中实心物体，颗粒和气泡的运动。了解气泡或沙子颗粒与环境水的动态相互作用对于正确设计和优化工程系统非常重要。 现象的复杂性以及理解控制参数（例如喷嘴大小，粒径，释放高度和喷嘴角）的影响的挑战需要考虑实验和数值方法。拟议的NSERC分散程序由四个项目组成，其目标是执行缩放分析并确定重要参数，例如喷嘴直径，粒径，释放高度，释放角度，释放角度和粒度分布在粒子云的运动上；测试和表征非牛顿流体混合物（例如屈服应力和明显粘度）的流变学；通过减少气泡尺寸和气泡速度来确定改善氧气转移的机制；确定基于缩放分析的喷嘴直径，喷嘴角和气流排放，并测试起泡喷射和羽流中的最佳空气水分；确定粘性流量混合物中气泡羽状的状态分类；在停滞的环境水中进行固体物体的运动，控制背景湍流和粘性混合物的数值模拟，并对停滞的环境水中气泡射流的运动进行验证测试，并研究两个相邻的气泡破裂和在两个相邻的气泡中的气泡破裂和合并。拟议计划的结果将帮助加拿大人确保更多的淡水，并使行业能够通过拟议的模型有效地回收和重用水为其活动。