Middle Route The Main Channel Section Of Unsteady Flow Numerical Simulation Studies

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.