応答曲面法を用いたフランシス形ポンプ水車ランナの最適形状設計

抄録

In the design of pump turbine runner, both performances in turbine operation and in pump operation must be considered. As for Francis pump turbine, which is the most widely used type of pump turbine, the decrease of runner inlet diameter improves the turbine efficiency; it moves the best efficiency point closer to the operation head range. However, such runner decreases the circumferential velocity at the runner outlet in pump operation and the total head is also decreased, so there is a trade-off between the performances in turbine operation and in pump operation. Additionally, since Francis pump turbine runner consists of fixed blades and the blades have three-dimensionality, the design with high performance runner needs plentiful design experience. However, the design dependent on experiences may not exploit the freedom of runner geometry, thus more efficient design system which utilizes the wide design space of the Francis turbine runner has been needed. In this study, we developed the automatic high-speed design system for Francis pump turbine runner with multi-objective genetic algorithm and response surface method.