中文摘要：

本文采用多目标遗传算法对轴流式水轮机叶片进行优化,从优化过程中产生的众多叶片中选取四种特征明显的叶片,并进行分析和对比,以研究不同叶片几何参数（包角、叶栅稠密度、叶片空间挠度）与水轮机运行性能之间的关系。研究结果表明：叶片空间挠度越大,叶片正背面压差越大,对空化性能越是不利;翼型弦长越短,叶片受力面积和叶栅稠密减小,缩小了水轮机的运行范围,且使得高效率区向大流量,小转速的工况移动;叶栅稠密度过大,流道间的排挤增大,水轮机损失增大,高效区范围也缩小。

英文摘要：

In this study, a multi-objective optimization approach with an intelligent algorithm is adopted to optimize the blade design of Kaplan turbine, and four blades with different characteristics were selected from the blades generated by this approach. Analysis and comparison demonstrates a relationship between turbine performance and geometric parameters of blades such as wrap angle, cascade solidity, and blade space deflection. The results show that an increase in blade space deflection leads to greater pressure differences between the pressure and suction sides of blade, an adverse condition to cavitation performance. And a shorter chord length of hydrofoil leads to a decrease in blade stress area and cascade solidity and thus to a narrower turbine operation scope, so that the high efficiency zone will move toward the range of high flow or low speed. A greater cascade solidity can increase the blockage of flow passage and more headloss in the turbine, which will also narrow the scope of high efficiency zone.