城市给水管网的计算方法及应用

应用有限元，线性化处理及优化方法，编写管网平差计算的ＦＯＲＴＲＡＮ程序。该程序可用于环状网或树状网有单水源或多水源的各种情形，且不受管网是平面的或立体的及环数多少的限制。     

山区城市给水管网规划实例

通过对一个山区城市给水管网规划实例的分析，提出在山区给水中应充分利用高差自流供水，并按照地形高差对给水管网进行分区，加压供水的区块与重力流供水的区块管网应相互隔断，同时，对长期运行在高水压下的管网，宜设置减压措施。     

城市给水管网状态模拟方法探讨

从微观和宏观模型两个方面阐述了给水管网状态模拟技术的最新进展。通过采用参数校正,采样定位,对控制元素的模拟等方法,能够使微观模型达到较高的精度;经验与理论公式相结合的方法可以弥补宏观模型的不足;采用神经网络方法对模型的不稳定情况进行分析,从而得出状态模型的不准确程度;采用模型驱动的神经网络方法建立给水管网宏观模型,建成的模型具有更好的学习能力和容错能力。     

微观建模在城市给水管网系统中的实践

给水管网系统动态建模是自来水公司实现科学管理、提高效益、提高服务水平的重要手段.以天津市给水管网系统建模为例,详细地阐述了给水管网系统微观建模的理论与方法.     

基于Biharmonic样条的离散数据三维地形生成方法

论述了利用Biharnonic样条曲面插值方法,实现不规则分布地形采集数据的曲面构造,并利用该算法结合visual C#语言编程实现三维地形图的生成和显示.     

基于蒙特卡罗法的城市给水管网可靠性分析

基于蒙特卡罗法对给水管网的可靠性进行了分析.提出了新的可靠度指标计算方法,对管网和各节点分别建立评价指标,并得出了定量的计算结果.通过对可靠性计算结果的分析,能有效识别出给水管网中的关键管段,模拟多管段同时处于故障状态的情况,可以作为给水管网可靠度优化设计的参考.     

微观建模在城市给水管网系统中的实践

给水管网系统动态建模是自来水公司实现科学管理、提高效益、提高服务水平的重要手段。以天津市给水管网系统建模为例 ,详细地阐述了给水管网系统微观建模的理论与方法。     

分形理论在城市给水管网布置中的应用

通过对分形理论和给水管网特点的研究,建立了一种新的定量描述给水管网空间分布状态的评价指标--管网覆盖度和管网覆盖深度。采用盒计数法计算给水管网规划布置的分形维数,将给水管网的规划布置由定性分析改为定量分析,从而为给水管网的定线和布局做出合理的指导,使给水管网的平面布置更加科学可靠。     

城市给水管网实用优化分区探讨与实践

提出了给水管网实用优化分区的概念。在水力模拟计算的基础上,结合我国城市给水管网系统实际情况,对城市给水管网进行分区,然后在分区的基础上再通过水力模拟计算进一步确定其合理性并完善方案。阐述了给水管网实用优化分区步骤,包括选择区域系统阶层数、划定区域规模、确定进水点数目和位置、划定区域边界等。将其应用于某大城市实际管网,取得了良好的效果。     

城市给水管网爆管点动态定位的神经网络模型研究

本文基于人工神经元网络原理，结合一个城市给水管网室内模型试验研究，通过BP神经网络模型的模式分类和辨别功能，对城市给水管网爆管点的动态定位进行了研究.得到了一些关于使用神经网络进行给水管网爆管点动态分析的重要结论.     

Pressure Management Model for Urban Water Distribution Networks

A technique for leakage reduction is pressure management, which considers the direct relationship between leakage and pressure. To control the hydraulic pressure in a water distribution system, water levels in the storage tanks should be maintained as much as the variations in the water demand allows. The problem is bounded by minimum and maximum allowable pressure at the demand nodes. In this study, a Genetic Algorithm (GA) based optimization model is used to develop the optimal hourly water level variations in a storage tank in different seasons in order to minimize the leakage level. Resiliency and failure indices of the system have been considered as constraints in the optimization model to achieve the minimum required performance. In the proposed model, the results of a water distribution simulation model are used to train an Artificial Neural Network (ANN) model. Outputs of the ANN model as a hydraulic pressure function is then linked to a GA based optimization model to simulate hydraulic pressure and leakage at each node of the water distribution network based on the water level in the storage tank, water consumption and elevation of each node. The proposed model is applied for pressure management of a major pressure zone with an integrated storage facility in the northwest part of Tehran Metropolitan area. The results show that network leakage can be reduced more than 30% during a year when tank water level is optimized by the proposed model.     

城市供水管网普查技术方法初探

对城市庞大的供水管网进行普查是一项复杂的系统工程。通过对武汉市武昌区供水管网的普查工作 ,探索和总结了一套较有成效的工作方法和程序。     

基于OpenGL技术的水下地形三维建模与可视化

针对传统水下施工设计存在的缺点，提出一种基于OpenCL技术的水下地形三维建模与可视化方法，该方法可以自动实现水下地形DEM模型的构建、三维可视化以及任意剖面分析，对于指导现代水下施工设计具有重要意义。     

Water Saving and Energy Reduction through Pressure Management in Urban Water Distribution Networks

Water shortages and climate change are worldwide issues. Reduction in water leakage in distribution networks as well as the associated energy saving and environmental impacts have recently received increased attention by scientists and water industries. Pressure management has been proposed as a cost-effective approach for reduction in water leakage. This study conducted a real-world water pressure regulation experiment to establish the pressure-leakage relationship in a district metering area (DMA) of the water distribution network in Beijing, China. Results showed that flow into the DMA was sensitive to inlet water pressure. A 5.6 m reduction in inlet pressure (from 38.8 m to 33.2 m) led to an 83 % reduction (12.1 l/s) in minimal night flow, which is a good approximator of leakage. These reductions resulted in 62,633 m³ of water saved every year for every km pipe, as well as associated savings of 1.1?×?10⁶ MJ of energy and 68 t of CO₂ equivalent greenhouse gas emissions. The results of this study provide decision makers with advice for reducing leakage in water distribution networks with associated energy and environmental benefits.     

Fictitious Component Free - Pressure Deficient Network Algorithm for Water Distribution Network with Variable Minimum and Required Pressure-Heads

Water Resources Management - The pressure-driven analysis is essential for modelling the pressure deficient condition of water distribution networks. Owing to the complexity, the development of...     

Pressure Management of Large-Scale Water Distribution Network Using Optimal Location and Valve Setting

Water Resources Management - This paper presents a new method to optimize the location and setting of Pressure Reducing Valves (PRVs) for adjusting the nodal pressure at different hours of a day by...     

Design of Water Distribution Network for Equitable Supply

Water shortage is experienced in different parts of the world in different magnitude. In certain countries, water deficit is a regular phenomenon and in some other countries it happens for a short duration, due to failure of any component in the system. Shortage of water at source can be best tackled by distributing the available water equally among the consumers. This paper deals with the design of water distribution network capable of equitable supply during shortage in addition to the satisfactory performance under non-deficit condition. Performance of a typical water distribution network, with shortage of water at source is illustrated in detail. Head dependent outflow analysis with extended period simulation, is used to determine the actual supply from each node to consumers. Relationship between duration of supply and volume available at source as well as supply from each node are established for understanding the behaviour of network under low supply situation. A term “inequity” which is the maximum difference in supply demand ratio among different consumers is presented. This is based on the actual performance of the network instead of surrogate measures, generally used for reliability. It is illustrated that the maximum “inequity” in supply in a network during the entire duration of supply can be estimated with single analysis. Design of a water distribution network, duly considering equity in addition to the cost minimization and minimum head requirement is presented. Genetic Algorithm is used for solving this multi objective problem. The solution technique is illustrated using two benchmark problems, namely two loop network and Hanoi network. Results show that considerable improvement in equitable supply can be achieved with additional investment on pipes above the least cost solution. Hence it is better to design networks duly considering deficit condition for better reliability. It is also illustrated that it will be difficult to improve equity beyond a limit for a given network, through selection of different pipe diameters.     

基于 LDV 测量速度场计算三维机翼表面压力分布

本文基于线路积分原理，用ＬＤＶ测量三维机翼周围的速度场，然后把它们作为已知量代入到雷诺方程，欧拉方程和贝努利方中去解压力。