Modelling of Two-Phase Transient Flow with multiple Surges in Storm Water Systems by the Shock-Fitting Technique

目前的雨水系统设计方法是基于能量和连续性方程的简化表示。这种过于简化的SWS设计导致了严重的问题和下水道的昂贵损坏（间歇泉，溢出，街道淹没，交通事故以及严重的电气问题）。2011年蒙特利尔发生了一个例子，位于勒内-莱维斯克街和圣凯瑟琳街之间的沃尔夫街的一个沙井在7月18日星期一变成了一个名副其实的间歇泉，喷射出数米高的雨水。被阻塞在雨水管道中的加压空气试图逃跑，带走了大量的雨水。一辆停在下水道金属盖上的汽车甚至被猛烈地反复抬起。拟议中的研究项目将解决这些安全问题。将建立一套有效的数值工具，用于计算SWS中的水动力条件，其中可以集成最佳管理实践（BMP）。这种新方法将注意到所有的流动类型，包括瞬态流动、空气的存在、非永久性摩擦、同时存在一个以上的加压/减压波、边界条件的复杂性以及人孔和BMP中的水储存。近年来个人计算机的发展促进了瞬态流模型中动态因素的引入。将推荐新的法规指导方针，将源和管道末端（EOP）控制集成到全球雨水管理解决方案中。该项目的研究结果（数字工具和SWS指南）将对未来和当前可持续SWS的设计程序产生重要影响。预计使用新工具将节省大量资金，因为未来的SWS将根据可持续标准进行设计，并且它们将导致长寿命的排水系统。Fuamba教授在过去五年中进行的与本提案相关的研究工作有助于开发城市排水领域的一些数字工具：（1）评估SWS的溢流风险，（2）分析人孔容量对涌浪传播的影响，（3）模拟SWS边界条件，（4）分析加压/减压波前特性和截留气穴，（5）用Goddham方法模拟瞬态两相流中的非定常摩阻。他的专业知识将有助于创造一套新的工具。

Current design methods for Storm Water Systems (SWS) are based on simplified representations of energy and continuity equations. This oversimplified design of the SWS has led to severe problems and costly damage to sewers (geysers, overflows, street inundations, traffic accidents and also severe electrical problems). An illustration of one of these problems happened in Montreal in 2011, where a manhole located on Wolfe Street, between the streets René-Lévesque and Sainte-Catherine, was turned into a veritable geyser on Monday July 18th, projecting sprays of storm water several meters high. Pressurized air that was blocked in the storm sewer tried to escape, taking with it large amounts of storm water. A car parked on the manhole metal cover was even violently raised repeatedly.The proposed research project will address these safety issues. An efficient set of numerical tools will be instituted for calculating hydrodynamic conditions in SWS where Best Management Practices (BMP) may be integrated. This new approach will take note of all flow types including transient flows, the presence of air, non-permanent friction, simultaneous presence of more than one wave of pressurization/depressurization, complexity of boundary conditions and water storage in manholes and BMP. The recent progress in Personal Computer advancements promote the incorporation of dynamic considerations in the transient flows modeling. New guidelines for regulations, integration of sources and End-Of-Pipe (EOP) controls into the global storm water management solutions will be recommended. The findings of this proposed project (numerical tools and SWS Guidelines) will have an important impact on the design procedure of future and current sustainable SWS. It is anticipated that significant money will be saved when using the new tools, because future SWS will be designed according to sustainable criteria and they will result in long lifespan drainage systems.Research work carried out by Professor Fuamba during the past five years related to the present proposal has contributed to the development of a few numerical tools in the urban drainage domain: (1) to assess the overflood risk in SWS, (2) to analyze the influence of manhole capacity on the propagation of the surge wave, (3) to model the SWS boundary conditions, (4) to analyze the pressurized/depressurized wave front behaviour and trapped air pockets, and (5) to simulate unsteady friction in transient two-phase flow with Godunov method. His expertise will be helpful in the creation of the new set of tools.