| In recent years, more and more researchers use the computational fluid dynamics—CFD in the analysis of internal flow field of the fluid machine, as well as the study and development of the waterpower model. This way has been the artery in the study and development of the waterpower model. Numerical calculation technique of CFD can get the distributing of the internal flow field in the fluid machine and the information of the internal flow status in the flow-passing parts relatively accurate. This not only provide theoretical basis for the research of the performance and the stability of the fluid machine and the engineering hydraulic, and also is the efficiency measure of the designing high-powered fluid machine successfully and optimizing remodel of the existing fluid machine.For the development of low-head hydropower resources, In the design of turbine runner, High specific speed Francis turbine have the advantages of high-speed, small size, high efficiency and high-performance wide-area, compact structures, which is an economic and appropriate type of turbine. At the present, the development of China's water resources sustained increasing, the middle-mall hydropower that the technology is economically feasible and technologically is very popular. So, the development of High specific speed Francis turbine model which have excellent performance can use the water resources more reasonably, sufficiently and effectively. And it can transform the advantages of the potential resource into the benefit of the economy and society, which have great significance.The main research and the major work done in this paper as follows:1. The geometric parameters are designed according to the flow channel of the hydraulic model that has similar head and specific speed, as well as the excellent performance. Using the dualistic Theoryω= 0 , In accordance with the request that runner have the highest speed and conveyance capacity, the higher maximum efficiency and average efficiency, the good cavitations performance, stability and the adaptability for changing work condition .etc. Initial scheme about the airfoil, cascade and the runner is designed for the HL300.2. Initial program of the runner is modeled three-dimensionally and mesh accurately. This lay the reliable basis for the precision of the CFD simulation and the accuracy of the performance prediction of the internal flow in the flow-passing.3. In this paper, the numerical simulation on the initial runner has been done by using Reynolds average N-S equation and RNG k-εturbulence model and SIMPLEC algorithm. In this numerical simulation, there are all 25 calculation points been selected on typical working conditions that are the big flow condition the optimal condition and small flow condition. With the simulation results to repair and adjust the cascade and aerofoil of initial blades, and other flow parts until satisfaction, finally design out the HL300 hydraulic model and draw the form drawing.Main innovations in this research work:1. Put forward the new method of split and assembling of the elbow of the draft tube base on Pro/E and solve the problem that occurred during the mechanical processing and modeling by the usual method and etc.2. A new hydraulic model with suitable prediction and good energy performance of the water head of 20m has been designed in this topic research.Due to the limits of time and conditions and my lack of experience, there are a lot of work not done well. Its doesn' t satisfied that the Hydraulic model in this paper, and technical performance indicators are not enough advanced too. There has further room for further study.
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