A piano key weir (PKW) is a solution for improving the efficiency and safety of reservoirs and simplifying their management. To investigate the influence of the inlet/outlet width ratio on the discharge efficiency of PKWs, a three-dimensional numerical model based on a standard turbulence model and volume-of-fluid (VOF) method is employed, and the flow characteristics of nine laboratory-scale PKWs with different ratios are studied numerically. The results confirm that PKW configurations with are generally superior to those with in terms of discharge capacity. However, as the water head rises, the discharge efficiency of the PKW with a greater decreases more rapidly. By decomposing the total discharge into inlet, lateral and outlet components, according to the flow features of each overflow crest and their contributions to the total discharge, the intrinsic influencing mechanism of on the discharge performance of PKWs is revealed.

中文翻译：

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进出水口宽度比对琴键堰排出量的影响

钢琴键堰 (PKW) 是一种用于提高水库效率和安全性并简化其管理的解决方案。为了研究入口/出口宽度比对PKWs排放效率的影响，采用基于标准湍流模型和流体体积（VOF）方法的三维数值模型，以及九个实验室的流动特性数值研究了具有不同比例的 PKW。结果证实，在放电容量方面，PKW 配置通常优于 PKW 配置。然而，随着水头的升高，较大的PKW的排放效率下降得更快。将总流量分解为入口、侧向和出口分量，根据各溢流峰的流动特征及其对总流量的贡献，