基于瞬变反问题分析的给水管网漏失数值模拟

Inverse transient analysis-based numerical simulation of leakage in water distribution systems

给水管网漏失问题亟待解决,而漏失的定点及定量是管网漏失控制研究的重要环节.为确定给水管网漏失点和漏失量,提出了基于水力瞬变分析的漏失数值模拟理论框架,指出该问题实质就是求解系统辩识反问题进行参数识别.首先设定漏失系数为系统待识别参数,并给出激励、响应以及二者间的传递模式.然后建立了反问题分析模型,应用特征线法计算雅可比矩阵,运用Newton-Raphson算法最小化压力测量值与计算值之间的偏差求解模型.最后通过算例管网阐明了数值模拟的具体步骤.

leakage of water distribution systems （WDS） has become a serious issue in the world. Seeking the location and the quantity of leaks is an approach to controlling them. So the theoretical frame of numerical simulation is presented to locate and quantify leaks in the WDS based on inverse transient analysis. First, it is pointed out that inverse transient analysis is, in substance, a sort of parameter identification problem. Then, the leak coefficient is defined as a parameter to be identified. At the same time, the stimulation function, response function and transfer function, respectively, are determined. Furthermore, the mathematical model of inverse transient analysis is presented. And then, the model is solved by use of the Newton - Raphson algorithm to minimize the difference between the calculated and measured heads at nodes and by using the Method of Characteristics to calculate Jacobian. Finally, the process of numerical simulation is performed on a sample pipe network.