The purpose of this research is to study the effect of different immersed depths on water wheel performance and flow characteristics using numerical simulations. The results indicate that the simulation methods are consistent with experiments with a maximum error less than 5%. Under the same rotational speeds, the efficiency is much higher and the fluctuation amplitude of the torque is much smaller as the immersed radius ratio increases, and until an immersed radius ratio of 82.76%, the wheel shows the best performance, achieving a maximum efficiency of 18.05% at a tip-speed ratio (TSR) of 0.1984. The average difference in water level increases as the immersed radius ratio increases until 82.76%. The water area is much wider and the water volume fraction shows more intense change at the inlet stage at a deep immersed depth. At an immersed radius ratio of 82.76%, some air intrudes into the water at the inlet stage, coupled with a dramatic change in the water volume fraction that would make the flow more complex. Furthermore, eddies are found to gradually generate in a single flow channel nearly at the same time, except for an immersed depth of 1.2 m. However, eddies generate in two flow channels and can develop initial vortexes earlier than other cases because of the elevation of the upstream water level at an immersed radius ratio of 82.76%.

中文翻译：

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使用实验和数值分析对水轮的浸入深度影响的性能研究

本研究的目的是通过数值模拟研究不同浸入深度对水轮性能和流动特性的影响。结果表明，模拟方法与实验一致，最大误差小于5%。在相同转速下，随着浸入半径比的增加，效率更高，扭矩的波动幅度更小，直到浸入半径比达到82.76%时，车轮才表现出最佳性能，达到最大效率在 0.1984 的叶尖速比 (TSR) 下为 18.05%。平均水位差随着浸入半径比的增加而增加，直至 82.76%。在较深的浸没深度处，水域面积更广，水体积分数在入口阶段表现出更强烈的变化。在82.76%的浸入半径比下，一些空气在入口阶段侵入水中，加上水体积分数的剧烈变化，使流动更加复杂。此外，除了浸入深度为 1.2 m 外，几乎同时在单个流道中逐渐产生涡流。然而，由于上游水位以82.76%的浸没半径比升高，涡流在两个流道中产生并且可以比其他情况更早地形成初始涡。