| Distribution of water resource is uneven in time and space in our country,so planning and construction of large and medium water supply project is animportant aspect of the current water conservancy construction. Shanxi bigwater network construction, based on the Yellow River and the Fenhe River inShanxi Province as the main line, interconnected the main reservoir rivers inthe province to achieve the water interconnection scheduling, improvereliability and security of water supply and provide basic protection forpeople’s life and economic stable development of the whole province.Central Yellow River diversion project, one important part of Shanxi bigwater network construction, intakes water from Tianqiao reservoir on theYellow River to watered area by using pumping station open channel tunnel,inverted siphon, and other hydraulic structures. The project includes an intake water conveyance tunnel from Tianqiao reservoir and the pumping stationproject after the tunnel. Analysis of hydraulic characteristics of water intakeproject includes unsteady flow calculation of open channel water, determiningthe water level of tunnel, flow process line, calculation of hydrauliccharacteristics of intake pumping station (calculation of steady-state operationand hydraulic transient process analysis)Based on the analysis and understanding above, the main contents of thispaper are:1) numerical simulation of open channel unsteady flow calculationmethod of three different sections of the gate arch type, round classes type andtrapezoidal type based on the hydraulic characteristics analysis of pressureaqueduct and open channel tunnel no pressure aqueduct of aqueduct project athome and abroad;2) developing program of different sections of open channelunsteady flow based on VB;3) predicting pump full characteristic curve data inaccordance with the different speed to improve the simulation accuracy oftransition process based on the need for calculation of the transition process ofpumping station;4) developing a forecasting system based on MATLAB as aplatform to provide the necessary technical support for simulation computingof pumping station transition process.The main conclusions are:(1) in pump complete characteristic curveprediction, BP-RBF neural network is formed by merging BP neural networkforecasting method and RBF neural network prediction method.(2) predictedresult is improved compared with BP neural network, deviation reduced,convergence time significantly reduced after combining the BP neural networkand RBF neural network.(2) the network structure in prediction of predictionprogram based on MATLAB platform is a more satisfactory network structurethat can be trained before the paper is completed. Due to some weights of theneural network are random parameters given by computer, which are differentin each training, after obtaining the satisfactory predicted results with small deviation, the weights of the network at the time is saved for calling in laterengineering practice.(3) in this study, arched gate type section is used in theproject. Process data of the water level, flow, velocity, clearance ratio insidethe no pressure tunnel change with time is analyzed by using characteristic linemethod to solve characteristic equation and the corresponding process line isdrawn. Corresponding relationship between flow of the pump water-in pooland the number of sets turned on is determined. Abandoned water of project isreduced and converted into tunnel clearance ratio according to Tunnel flowarea to ensure the clearance in process of water transportation within therequired security scope of standard.Central Yellow River diversion project is a complex system project.Calculation analysis of open channel unsteady flow includes many things, suchas connection issue between open channel with different sections, open andclose issue of sluice gate, control and scheduling issue of the entire system.Further in-depth study is needed. |
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