南水北调中线总干渠河南段非恒定流数值模拟研究

【作者】 周琼；

【导师】 马跃先； 李占松；

【作者基本信息】 郑州大学 ， 水利水电工程， 2007， 硕士

【摘要】 南水北调中线工程是为解决我国水资源分布不均并严重影响北方地区经济发展问题而兴建的一项特大型跨流域，具有战略性意义的宏伟工程。明渠输水是开敞式输水系统，它的特点是具有较大的超设计输水能力；而由于地形或其它建筑物交叉等原因，在调水工程中的长距离输水系统中，需要采用明渠和有压管道相结合的形式；明渠中的非恒定流往往是由闸门或泵站的开启和关闭等人为因素导致；为满足实际输水的需要，需要进行水力过渡过程计算，确定由各种原因引起系统非恒定流时该系中的水位、流量、流速、水深等水力要素沿流程和随时间的变化规律，以设计出更加优化的长距离输水系统，因此水力过渡过程是长距离输水系统中普遍存在的现象。进行非恒定流数值模拟计算，分析过渡过程中的水流特性，对输水系统的设备的设计和运行都具有重要意义。本论文主要以明渠非恒定流理论为基础，从南水北调中线工程总干渠河南段的具体工程情况出发，针对长距离输水系统中存在多处渡槽、暗渠、倒虹吸及连接段等复杂连接管道的明渠非恒定流数值模拟方法展开研究，并对惯性水头及糙率选取的影响进行深入的分析，最后通过对非常运用工况最高水位推算及控制关闸方式的改变，分析水面线的变化，定性分析最佳调度方式，以便对实际工程中调度运行方式进行指导，同时为了更好的服务于实际工程，对数值模拟的可视化进行研究，具体将围绕以下几个方面展开：1．首先建立对简单棱柱形渠道在设计流量下启闭闸门时的非恒定流数学模型，并采用多种计算方法进行数值模拟，对计算结果进行比较，选用最佳计算方法。2．对节制闸突然关闭使渠道中流速突然变化所引起的水位交替升降的水力现象进行全面理论分析。3．从一维明渠及有压管非恒定流连续性方程和运动方程出发，详细论述管渠结合中各类边界条件的处理方法；并结合南水北调中线工程某段实例，对运行中上下游闸门同时关闭工况下下游闸前水深的变化情况进行模拟。4．从能量角度出发，分析管渠结合一维非恒定流系统中倒虹吸进出口断面能量损失，对是否考虑有压管惯性水头的影响进行分析比较，并分析糙率的选取对水面线的敏感度。5．通过控制关闸方式改变边界条件，分析水面线的变化，定性分析最佳调度方式，以便对实际工程中调度运行方式进行合理指导。6．论文利用Matlab语言编制程序计算，用VisualBasic开发应用程序，对南水北调中线总干渠河南段所有节制闸在非常运行工况下的数值模拟结果进行可视化显示。最后显示以下四类渠段运行结果图：a)断面流量随时间变化图b)断面水深随时间变化图c)某一时刻各断面流量变化图d)某一时刻各断面水深变化图更多还原

【Abstract】 The Middle Route of South-to-North Water Transfer Project is a great strategic significance water transfer project which has been programmed and built in China across drainage basin in order to solve the water resources problem in northern areas. Channel flow is a opening wide -like water transfer system with the bigger ultra design water head. As the reasons of terrain or other buildings overlapping and so on, the Canal-pipes conjunctive system is needed in the long distance water transfer project. Unsteady channel flow has always been caused by the opening or closure of strobe and pumping station. In order to satisfy the water distribution, it is necessary to simulate on the water power transient processing and to determine the rules which follows the change of flow and time of every hydraulic elements as water level, current capacity, speed of flow, water depth in unsteady channel flow system which is caused by all kinds of reasons, and then to design the optimizes items in the long distance water - carriage system. Therefore the water power transient process is the common phenomenon in the long distance water - carriage system. It has vital significance to design and operate the water-carriage system’s equipment to simulate the unsteady flow and to analysis the fluent characteristic of the transient process.This paper mainly takes the unsteady flow theory as a foundation, it bases on the concrete situation of the main channel in the South -North Water Transfer to the Middle Route Project (He Nan section), it studies on unsteady flow simulation method of all kinds of complex conjunctions in the long distance water - carriage system, such as aqueducts、covered ditches、inverted siphons、connection sections and so on . and it deeply analyzes the impacts on choosing the inertia head and the roughness.Finally ,it analyzes the changes of water surfaced and the optimal dispatching control by calculating the highest water level and changes the control pattern of closing the gate under special working condition, so that it can afford effective theory guidance in the actual project. At the same time ,in order to provide better service for the actual project, it has researched on visualization in unsteady flow numerical simulation . Its main ideas are shown as follows:1. Firstly establishing numerical models for unsteady flow in simple prismatic channel under the design discharge when the gate lifting, introducing some calculation methods to calculate, and comparing the results ,and then selecting the best method of calculation.2. Secondly, completely discussing the theoretical analysis of water power phenomena of rise and fall of water level which is caused by sudden closing of the control sluice lead to the sudden flow rate change.3. Thirdly, based on the continuity equation and dynamic equation of one-dimensional open channel and confined tunnel, detailing different processing methods of boundary conditions researches in the canal-pipes conjunctive system. Then taking a project in the South -North Water Transfer to the Middle Route as a example simulating the water depth before the downstream gate when the upstream and downstream gate in generation are shut at the same time4. Fourthly, analyzing the energy loss of cross-section of Series connection inverted siphons of canal systems based on the energy theorem principle. Paying attention to and comparing the inertia force in this procedure through calculating, and analyzing the water facial suture sensitivity of roughness coefficient selection.5. Fifthly, changing the boundary condition, analyzing the changes of water surface and selecting the optimal dispatching control by changing the control pattern of closing gates, so that it can afford effective theory guidance in the actual project.6. In this paper, Matlab language is used on numerical computation, and Visual Basic language is used to establish an application program. It demonstrates the visualization of numerical simulation results of all gates control pattern under special working condition in He Nan Canal Section in Middle Line of S-N Water Transfer Project.Finally, four kinds of charts on results about canal sections are shown as follows:a) charts about the variation of Discharge of Cross Section with time .b) charts about the variation of water depth with time.c) charts about the variation of Discharge of Cross Section at one moment.d) charts about the variation of water depth at one moment.更多还原