energy equation is employed [7], wi

energy equation is employed [7], with the elevation difference between the gutter water level and the point of discharge being equated to the head losses in the system. However, steady-state design methods are not truly applicable when a siphonic system is exposed to a rainfall event below the design criteria, or an event with varying rainfall intensity. Furthermore, current design methods cannot account for commonly occurring operational problems, such as the blockage of outlets and the submergence of the system exit due to down- stream sewer ooding. 3. Description of research As mentioned previously, the main aim of the work detailed herein was to develop a numerical model, capable of accurately simulating the operational perfor- mance of roof drainage systems. As such, it was envisaged that the model would have to be able to route rainfall from roof surfaces down to ground level. To achieve this, it was necessary to undertake both experimental and numerical work. Experimental data concerning the performance of conventional systems during extreme rainfall events are very scarce. It was therefore necessary to undertake laboratory-based experimental work to determine the operational characteristics of conventional systems under such conditions. In contrast, the performance of siphonic systems under all types of rainfall events is relatively well understood, primarily as a result of a research programme initiated at Heriot-Watt University in 1996 [8]. Consequently, no further siphonic experi- mental work was required. In terms of numerical modelling, it was necessary to develop new sub-routines to simulate the ow condi- tions on roof surfaces, along gutters and within conventional system pipework. With respect to siphonic system pipework, much of the developmental work had already been completed during previous research projects [8]. However, the complexity of the existing numerical sub-routines has been found to often lead to numerical instabilities and result in extended computa- tional run times; both of these drawbacks restrict the general applicability of the model. Consequently, it was considered necessary to simplify the modelling techni- ques associated with siphonic systems. 4. Laboratory investigations As the capacity of conventional roof drainage systems is controlled primarily by the capacity of the gutter outlets, the main purpose of the laboratory work was to investigate the ow conditions in the vicinity of the outlets, and their dependence on gutter cross-sectional characteristics

結果 (中文) 1:

能量方程采用[ 7 ]，与排水沟水位和放电被等同于系统中的水头损失点之间的高程差。然而，稳态设计方法并不真正适用时，虹吸系统暴露于降雨低于设计标准，或与不同降雨强度的事件。此外，目前的设计方法无法考虑常见的操作上的问题，如出口，系统退出由于下淹没流淹没堵塞下水道。3。描述的研究如前所述，这项工作的主要目的是详细的规定建立数值模型，能够准确地模拟操作性能的屋面排水系统的性能。因此，它的设想是，模型将不得不从屋顶可以路由降雨面到地面。为了实现这一目标，有必要进行实验和数值工作。有关的实验数据的常规系统的极端降雨事件期间的表现是非常稀少的。因此有必要进行实验室的实验工作，以确定在这种情况下，传统系统的运行特性。相反，虹吸系统的所有类型的降雨事件下的性能是比较好理解的，主要是由于一个研究计划在1996 [ 8 ]赫瑞瓦特大学发起的。因此，没有进一步的虹吸实验心理工作所需的。在数值模拟方面，有必要制定新的子程序来模拟流条件的屋顶表面，沿沟，并在常规系统管道。相对于虹吸系统管道，大部分的开发工作已经被以前的研究项目[ 8 ]中完成的。然而，现有的数值子例程的复杂性已经发现，往往会导致数值不稳定和扩展的计算结果合理的运行时间；这些缺点都限制了模型的普遍适用性。因此，它被认为是必要的简化建模技术与虹吸系统有关的问题。4。实验室检查作为常规屋面排水系统的容量是由排水沟出口能力的主要控制，实验室工作的主要目的是探讨在出口附近的流条件，他们在天沟截面特性的影响

結果 (中文) 2:

能量方程是放电的就业 [7]，与天沟水位与点之间的高差被视同到水头损失在系统中。然而，稳态设计方法不是真正适用的当一个虹吸系统暴露在低于设计标准，降雨事件或事件具有不同降雨强度。此外，当前设计方法无法解释通常发生的业务问题，如堵塞的零售商和淹没的系统退出由于下游下水道过遭遇洪水。3.正如前面提到说明，本文中详细的工作的主要目的是研究的发展一种数值模型，能够准确地模拟业务性能-曼斯屋顶的排水系统。为此，它设想模型会有能到路线降雨从屋顶到地面的表面。要实现这一目标，有必要进行实验和数值模拟工作。实验数据关于极端降水事件期间常规系统的性能是非常稀少的。因此，有必要开展基于实验室的实验工作，以确定在这种条件下常规系统的业务特点。相比之下，在所有类型的降雨事件下虹吸系统的性能是较为清楚地了解，主要原因是在 1996 年 [8] 赫瑞瓦特大学发起的研究方案。因此，还需要没有进一步虹吸式试验-心理工作。在数值模拟，这是有必要开发新分例程来模拟 ow 工矿企业，屋顶上表面，沿排水沟和常规系统管道内。关于虹吸系统管道，很多的发展工作已经在以前的研究项目 [8] 期间完成。然而，已发现现有数值分例程的复杂性，往往导致数值不稳定性和导致扩展的 computa 传统运行时间 ；同时这些缺点限制模型的普遍适用性。因此，它认为有必要简化建模技术-什么是电流互感器与虹吸系统相关联。4.实验室调查能力作为常规的屋顶的排水系统主要由装订线零售商的能力，控制、 实验室工作的主要目的是调查 ow 条件附近网点，装订线横截面特性及其依赖性