The performance of a waterfall-type cross-flow hydraulic turbine was investigated via experiment and numerical simulation. The experiment was carried out using a cross-flow hydraulic turbine operating in a two-dimensional waterfall, and the result was compared with a corresponding numerical result analyzed by the volume of fluid method. The experimental results show that the maximum efficiency reached approximately 60%, higher than that of previous experiments in the literature. It was also confirmed that the recorded experimental efficiency was well reproduced in a two-dimensional numerical simulation, suggesting the validity of the numerical results. Furthermore, flow fields of the turbine were studied based on phase-averaged particle image velocimetry measurement and the numerical simulation. These results indicate that the flow and torque mechanisms of the cross-flow hydraulic turbine studied are explained by stagnation pressure on the concave side of blades and a Coanda-like flow on the convex side of the blades at small angle of blade position, followed by the formation of a high-velocity region within the turbine and flow impingement on the downstream blades at large angle. These flow field variations generated an increased local torque at small angle and a moderate torque at large angle. The improved efficiency was obtained by optimizing the off-axis distance to the waterfall and the tip-speed ratio of the hydraulic turbine, which were examined by a visualization of the flow through the turbine and the local torque distribution with respect to the angle of blade position, respectively.

通过实验和数值模拟研究了瀑布式贯流式水轮机的性能。实验在二维瀑布中运行的错流式水轮机上进行，并与相应的流体体积法分析的数值结果进行了比较。实验结果表明，最大效率达到了约60%，高于文献中先前的实验。还证实记录的实验效率在二维数值模拟中得到了很好的再现，表明数值结果的有效性。此外，基于相平均粒子图像测速测量和数值模拟研究了涡轮机的流场。这些结果表明，所研究的贯流式水轮机的流动和扭矩机制可以用叶片凹侧的停滞压力和叶片位置小角度下叶片凸侧的附壁流来解释，其次是在涡轮内形成高速区域并以大角度对下游叶片进行流动冲击。这些流场变化在小角度产生增加的局部扭矩，在大角度产生中等扭矩。通过优化到瀑布的离轴距离和水轮机的叶尖速比来提高效率，通过涡轮机的流量和相对于叶片角度的局部扭矩分布的可视化来检查这些位置，分别。