冲击式水轮机是一种特别适用于高水头和超高水头段水力资源开发的流体机械，在我国超高水头水力资源开发中具有广阔的应用前景。冲击式水轮机的流动过程复杂，其转轮水斗受高速射流的周期性冲击易发生疲劳破坏。随着冲击式水轮机单机容量逐渐向大型化方向发展，亟需开展大型冲击式水轮机转轮的流固耦合研究以完善转轮结构的优化设计，为我国自主研制超高水头巨型冲击式水轮机组积累经验。 本文以大容量六喷嘴冲击式水轮机为研究对象，首先采用数值方法分析了单喷嘴射流作用下转轮流道内的三维多相非定常流动特性，结合性能特性参数的变化对流动状态进行研究。在设计水头，转轮的水力效率随喷针开度的增大先上升，在最优开度0.51sn达到峰值后开始下降；相较于最优开度，转轮的相对水力效率在0.64sn工况下降了1.13%，大开度工况下的水斗切口漏流是水力损失明显上升的重要原因。在设计开度，转轮的水力效率随水头升高先上升，在0.95倍设计水头的运行工况达到峰值后下降；在计算的最低和最高水头工况下，转轮的相对水力效率相比最优水头工况分别下降了0.97%与0.48%；偏设计水头工况下，水流以较高绝对速率由水斗出水边出流，未充分转换的水流动能是水力损失的主要原因，且偏设计水头工况下的出流损失在时空分布上均存在明显差异。 基于单喷嘴射流作用下转轮水斗的三维非定常流动模拟结果，开展了转轮水斗的流固耦合特性数值分析；对水斗表面多个应力监测点进行分析，发现水斗根部监测点的平均动应力受射流冲击的影响最大，其次为分水刃正面、背面与出水边外缘的部分测点，而水斗正面部分位置的平均动应力最小。转轮各水斗特殊的悬臂梁结构导致其根部在射流冲击作用下会发生明显的应力集中，动应力的最大值与最大幅值均位于水斗根部最底端，分别为77.6MPa与61.3MPa。最后对转轮水斗分别在空气与单射流作用下进行了模态计算，得到了转轮约束模态、干模态、湿模态的前六阶振型。对比发现，转轮水斗的前六阶干模态与湿模态中，同阶干模态、湿模态的振型以及频率之间的差异小，说明单股射流作用在冲击式水轮机转轮上的水膜流对转轮结构的附加质量效应不明显。

The Pelton turbine is a type of hydraulic turbine particularly suitable for medium, high and ultra-high head hydropower exploitation with great application prospects in China. The internal flow of the Pelton turbine is complicated, and the bucket on the Pelton runner suffers from the fatigue damage caused by the periodic impingement of the high-speed water jet. The studies on fluid-solid interaction of the Pelton runner need to be carried out for refining and optimizing the runner structure as the unit capacity gradually increases, as well as accumulating experience for the independent development of ultra-high head huge Pelton turbines in the future. In this paper, three-dimensional unsteady simulations were conducted to analyze the internal flow behavior of single jet impinging a large capacity prototype Pelton turbine. With other parameters unchanged, the hydraulic efficiency of the runner first rises and then decreases as the opening increases. The relative hydraulic efficiency of the highest opening decreased by 1.13% compared with the optimum opening, and the obvious leakage flow from the bucket cutout with high total pressure accounted for the increase of the hydraulic loss under the high opening. With other parameters fixed, the hydraulic efficiency of the runner increases and then decline as the operating head increases; the relative hydraulic efficiency under the lowest and highest operating head conditions decreases by 0.97% and 0.48% respectively comparing with the optimal. The additional kinetic energy carried by the outflowing water sheet flow discharging from the brim is the important source of loss under the partial head condition. Furthermore, the spatial and temporal distribution of the outflowing loss differs between the low and high operating head conditions. Based on the numerical result of the single jet impinging Pelton runner under design condition, the numerical simulation of the fluid-structure interaction of the prototype Pelton runner was carried out, and the dynamic stresses were monitored and analyzed at multiple measurement points distributed on the front and rear bucket surface as well as the bucket root. Results showed that the averaged dynamic stress at the bucket root was most influenced by the impingement of the jet, followed by several points at the front and rear surface of the splitter, the outer edge of brim, and the bucket root varied significantly with an amplitude larger than 20MPa, while the dynamic stress on other points varied comparatively smoothly. The maximum value and maximum amplitude of dynamic stress are 77.6MPa and 61.3MPa respectively, and they both occurred at the middle of the bucket root rounding surface. Solutions need to be done in optimizing the bucket root geometry to relief the stress concentration. The modal study was carried out to acquire the first six bound, dry and wet modals of the Pelton runner. The result showed that there was little difference between the vibration patterns as well as frequencies of the same order of dry and wet modals. The added mass effect of the single water jet on the Pelton runner is implicit.