The Study Of Fluid-structure Coupling And Vibration Of Pelton Turbine Runner

With the development of high-head hydropower resources at home and abroad, the development of pelton turbine becomes more rapid. Especially in recent years, The development of pelton turbine from single nozzle, double nozzles, low capacity has been developed up to six nozzles, stand-alone capacity of 120,000 kW turbine oblique strike now. China is in the key stage of researching and development pelton turbine. And on the study of fluid-structure coupling and vibration characteristics of pelton turbine research is not deep enough.Now, with the deepening of the pelton turbine research, such as the modern jet theory, fracture mechanics and so on. The study on internal flow theory and damage theory of Pelton turbine become clear. With the development of modern materials science and casting technology, more new materials and technology has been applied to design and manufacture on pelton turbine. Although the internal flow of Pelton turbine have a certain depth analysis and research at home and abroad. It can well be verified by simulation and experiment. But the study of flow characteristics of fluid-structure coupling and vibration characteristics of the buckets of Pelton turbine are not deep. The research can well obtained the characteristics of bucket under the jet flow field, and more important is to analyze the influence of stress distribution of runner bucket under the fluid-structure coupling. Furthermore, it can be analysis the reasons of crack on bucket root. The research has made the following achievements.1. According to the runner data supplied, modeling full three-dimensional model from nozzle outlet to bucket. Proposing a method of complex three-dimensional surface modeling on bucket root.2. It has calculated the flow characteristics under different heads of runner. And analysis the internal pressure distribution, velocity distribution under the jet.3. Wiht the interactive interface of Fluent and Workbench 14.0. It has calculated the deformation and stress characteristics under the fluid- structure coupling of bucket.4. It has calculated the vibration characteristics of bucket by jet force. The results show that: the first natural frequency is not the same number of levels with the jet impact frequency. The runner is not occurring the resonance under normal operating conditions.