Drop structures in drainage systems

污水收集和雨水排放系统是本港城市基础设施的重要组成部分。目前的系统受到城市增长、气候变化和老龄化的挑战。为了有信心地延长我们现有下水道系统的使用寿命，并最大限度地减少扩建和改造的成本，迫切需要对系统组件的水力学进行研究。本计画旨在探讨我国下水道系统中各种落差结构的效能。落差结构用于连接浅下水道和深下水道。将解决下落结构设计中的两个关键问题：1）下落结构损失了多少能量，以及2）下落流夹带了多少空气。三名研究生将就此主题进行论文研究：一名博士生将对水滴结构的比例模型进行实验室实验，另一名博士生将使用商业计算流体动力学（CFD）软件包进行相应的数值模拟，一名硕士生将对我们现有的水滴结构进行现场测量。这项拟议中的研究是阿尔伯塔大学的三位教授、斯坦泰克咨询公司和埃德蒙顿市的工程师之间的合作研究。将推广该项目的成果，为改进目前的市政服务准则提供基础。该项目预计将产生巨大的经济效益，因为它将有助于优化下水道系统的设计和建设，并最大限度地减少扩建和改造的成本。

Sewage collection and stormwater drainage systems are a vital component of our urban infrastructure. Current systems are challenged by a combination of urban growth, climate change, and aging. In order to confidently extend the useful life of our existing sewer systems and to minimize the cost of expansions and retrofits, research on the hydraulics of the system components is urgently needed. This project proposes to investigate the performance of various drop structures in our sewer systems. Drop structures are used to connect shallow sewers to deep sewers. Two key questions in the design of drop structures will be addressed: 1) how much energy is lost at drop structures, and 2) how much air is entrained by the falling flow. Three graduate students will conduct their thesis research on this topic: one PhD student will conduct laboratory experiments on scale models of drop structures, another PhD student will conduct corresponding numerical simulations using a commercial computational fluid dynamics (CFD) software package, and an MSc student will carry out field measurements of our existing drop structures. The proposed study is a collaborative research effort among three professors at the University of Alberta, and engineers at Stantec Consulting and the City of Edmonton. The results of the project will be generalized to provide a basis for improving current municipal servicing guidelines. This project is expected to generate a tremendous economic benefit, as it will help in optimizing the design and construction of sewer systems, as well as in minimizing the cost of expansions and retrofits.