Dynamics of Air/Water Two-phase Flows in Environmental Hydraulics

了解空气/水两相流的动力学在许多科学和工程领域（包括环境水力学）具有根本的重要性。由于流动的复杂性以及测量设备、计算能力和实地研究困难的限制，我们在这一领域的知识仍然有限。拟议的研究将利用阿尔伯塔大学的优秀实验室设施进行实验研究和数值模拟的水射流破碎空气和空气夹带和质量转移下降的水射流到水池。主要开展了以下几个方面的研究工作：（1）研究了不同几何形状的单股射流和多股射流在空气中的破碎过程。测量水滴破碎后的特性，并对射流破碎过程进行数值模拟。(2)将研究由倾翻射流产生的水池中气泡的动力学，并测量空气/水的质量传递量。这些研究的结果将被推广和发展为工程应用。(3)将对一种新的工程设计进行进一步的探索性研究，以改善充氧和利用水射流防止极端洪水事件期间桥梁倒塌。拟议的研究将为四名博士生和五名暑期本科生提供极好的培训机会。这项研究将允许开发实用工具，包括各种类型工程应用的数值模型，如大坝溢洪道的设计改进，以防止气体过饱和和鱼类死亡（即，气泡病）、通风和下水道系统中的气味控制。这项研究还将使我们能够设计有效的注氧系统，以提高河流和湖泊以及废水处理设施中的溶解氧水平。**

Understanding the dynamics of air/water two-phase flows is of fundamental importance in many areas of science and engineering, including environmental hydraulics. Our knowledge in this area is still limited due to the complex nature of flows as well as limitations in measurement devices, computing power and field study difficulties. The proposed study will take advantage of the excellent laboratory facilities available at the University of Alberta to conduct experimental studies and numerical modeling of water jet breakup in air and air entrainment and mass transfer by falling water jet into water pools. A number of research projects will be conducted: (1) Water jet breakup in air will be studied for single jets of different geometries and multiple jets. The characteristics of the water drops after their breakup will be measured, and numerical modeling of the jet breakup process will be conducted. (2) The dynamics of air bubbles in a water pool generated by a plunging jet will be studied, and the amount of air/water mass transfer will be measured. The results of these studies will be generalized and developed for engineering use. (3) Additional exploratory studies will be conducted on a novel engineering design for improving oxygenation and utilizing water jets for preventing bridge collapse during extreme flood events.***The proposed research will provide excellent training opportunities for four PhD students and five summer undergraduate students. This research will allow the development of practical tools including numerical models for various types of engineering applications, such as design improvement for dam spillways to prevent gas supersaturation and fish kill (i.e., bubble diseases), ventilation and odour control in sewer systems. This research will also allow us to design effective oxygen injection system to improve dissolved oxygen levels in rivers and lakes as well as in wastewater treatment facilities. **