| Impulse turbine is very common in the upper reaches of rivers and high mountains and one of the main models of water resources development in China, which has some merits such as simple structure, high-head, the installation height from the cavitation conditions, adapting to the power station with the flow variation is larger and so on. high head, high-capacity and multi-nozzle Pelton turbine is the main direction of research. But with the increasing in capacity and the number of nozzles, the flowing of Pelton turbine, jet interference and fluid-solid coupling problem of the research is becoming increasingly important. Based on the conclusion to relevant information in this paper, factors of the Pelton turbine, structural requirements, as well as flow characteristics and future prospects are reviewed. Especially, it carried out a detailed analysis of nozzle for fluid-solid coupling on the structure of multi-nozzle flow field, which provided some valuable reference.The stability of jet is a very important factor that affects efficiency and output as well as the vibration of impulse turbine. Instability of jet will cause vibration, noise, cavitation and fatigue cracks, which will cause a serious accident scoop off the turbine. Therefore, after the analysis of the flow in the needle, flow-solid coupling, interaction between the flow field and structure field, and the stability of jet, its proposed nozzle, flowing shape of nozzle in the Pelton turbine, excellent programs are made out to ensure Pelton turbine stable operation.In ansys11.0 Workbench simulation environment, by technical software CFX, five three-dimensional models of nozzle and needle, mesh generation, numerical simulation and calculation have been finished. Respectively, we can gain five nozzles structure model and the needle jet flow speed and pressure distribution as well as losses of flow through the calculation and analysis, pointing out the shortcomings of the original tradition of the program, and ultimately giving a better optimization of the spray nozzle needle shape of flow channel geometry, and providing a reliable basis for the nozzle and needle spray structural design.At the same time, in ansys11.0 Workbench this papers also uses components of the Simulation of structural statics, modal, as well as the principle of fluid-structure coupling analysis. As for The achievement of the water pressure on the nozzle wall to impose precise, the flow field analysis the structure impact on, a one-way fluid-solid coupling calculation, the stress distribution in the nozzle and the point of maximum stress value, so this paper conclude improvements to the structural design of the nozzle, provides the basis for strength calculation, but also calculated the nozzle natural frequency and the coupling frequency. The accurate frequency value and vibration-shaped come out, so we can learn the important conclusions: to a certain extent, water pressure and stress of the combined effects on the nozzle influence the modal frequency of nozzle, compared in the air. But in the low-frequency area, this is not obvious. The result of this study is of great significance to ensure stable operation of Pelton turbine.
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