长距离调水系统明满流耦合水动力学模型研究及其应用

发布时间：2018-12-15 18:56

【摘要】：水资源短缺及分布不均是我国水资源存在的两大劣势,这严重阻碍了经济和社会发展,我国不得不修建大批的长距离调水工程来解决这些难题。而对于跨流域的长距离调水工程,由于流域广且控制建筑物较多,实验模拟调度是非常困难的,如果不对工程进行计算模拟直接投入使用,一旦发生事故损失将是难以承受的。而数值模拟方法具有经济和方便的特性,成为众多研究者新的突破口,找寻更加实用安全的数值模拟方法对整个调水工程意义重大。本文通过研究以往的相关理论,建立了适用于具有复杂内边界的长距离调水明满流交替的一维非恒定流水力学系统。为了精确模拟流动的水力特性,分析明满交替流对工程运行的安全性和稳定性带来的复杂影响,采用圣维南方程组和Preissmann窄缝法来计算有压管流和自由表面流以及这两种状态的过渡流等问题,模型方程的离散方式为变量交错定义隐格式,并用一阶迎风插值的方法来处理对流项,并加入水库、泵站、分水口、暗涵及闸堰等水工建筑物。通过模拟了有压管流和Wiggert实验,模型计算结果与实验结果误差较小,证明模型可以用于模拟一维明满过渡流,然后将系统应用到模拟南水北调中线工程北京段一期自流工况的水力特性问题,较好地解决了工程中遇到明满流耦合计算的问题,并比较了关键点水位的模拟值与实测值,显出了较高的准确性。然后又模拟了南水北调中线工程北京段检修工况和二期工况,分析管内流量分布和水位变化,为长距离调水工程流网的设计和相关部门的调度决策提供依据,表明本文方法可以作为大型明满交替流输水工程的计算模拟工具。
[Abstract]:The shortage and uneven distribution of water resources are two major disadvantages of water resources in China, which seriously hinder the economic and social development. China has to build a large number of long-distance water transfer projects to solve these problems. However, for the long-distance water transfer project across the river basin, it is very difficult to simulate the operation of the experiment because of the wide watershed and more control buildings. If the project is not directly put into use, once the accident loss occurs, it will be difficult to bear. The numerical simulation method has the characteristics of economy and convenience, and has become a new breakthrough for many researchers. It is of great significance to find a more practical and safe numerical simulation method for the whole water transfer project. In this paper, by studying the previous theories, a one-dimensional unsteady flow mechanics system with complex internal boundaries is established, which is suitable for the alternation of long distance water transfer and full flow. In order to accurately simulate the hydraulic characteristics of the flow, the complex effects of the alternating flow on the safety and stability of the project are analyzed. The Saint-Venant equations and Preissmann's narrow slit method are used to calculate the pressure pipe flow, free surface flow and the transition flow in these two states. The discretization of the model equations is based on the variable staggered definition of implicit scheme. The first order upwind interpolation method is used to deal with the convection term, and the hydraulic structures such as reservoirs, pumping stations, water dividers, hidden culverts and sluice dams are added. By simulating the pressure pipe flow and the Wiggert experiment, the error between the model and the experimental result is small. It is proved that the model can be used to simulate the one-dimensional open full transition flow. Then the system is applied to simulate the hydraulic characteristics of the first stage self-flow in the Beijing section of the South-to-North Water transfer Project, which solves the problem of the open-flow coupling calculation in the project, and compares the simulated and measured water level at the key points. It shows high accuracy. Then, the maintenance condition and the second stage condition of Beijing section of the South-to-North Water transfer Project are simulated, and the flow distribution and water level change in the pipe are analyzed, which provides the basis for the design of the drift-net of the long-distance water diversion project and the dispatching decision of the relevant departments. It is shown that this method can be used as a numerical simulation tool for large alternating flow water conveyance projects.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TV68;TV133

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