Hydro energy is a kind of typical renewable energy, which can be converted by hydraulic machinery. However, tip leakage vortex (TLV) has a significant negative influence on the flow pattern and energy performance of hydraulic machinery. In this paper, a bending shrinkage groove (BSG) is proposed to suppress the TLV and improve the energy performance of a hydrofoil first, and then a parametric optimization design method is briefly introduced and applied to determine the optimal configuration of the groove. The main geometric parameters of the groove are selected as optimized variables and three different groove configurations are selected from the optimization result. Finally, the performance improvement of the hydrofoil with groove, the sensitivity analysis of the optimization variables, and the groove impacts on the TLV and flow patterns are investigated. The results demonstrate that the preferred groove reduces the non-dimensional Q criterion vortex isosurfaces area (Q_area = 2 × 10⁷) by 5.13% and increases the lift drag ratio by 17.02%, comparing to the origin hydrofoil. Groove depth d and groove width w are proved to have more significant impacts on the hydrofoil energy performance. The TLV and flow patterns are greatly affected by the different BSG configurations, and the wider BSG contributed to reducing the area of TLV, at the cost of energy performance deterioration.

中文翻译：

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带尖端间隙的翼型弯曲收缩槽的涡旋抑制和能量改善方法

水能是一种典型的可再生能源，可以通过液压机械进行转换。但是，尖端泄漏涡流（TLV）对液压机械的流型和能量性能具有重大的负面影响。本文提出了一种弯曲收缩槽（BSG）来抑制TLV并改善水翼的能量性能，然后简要介绍了一种参数优化设计方法，并将其应用于确定槽的最佳构型。选择凹槽的主要几何参数作为优化变量，并从优化结果中选择三种不同的凹槽配置。最后，改进了带槽水翼的性能，对优化变量进行了敏感性分析，并研究了沟槽对TLV和流型的影响。结果表明，优选的槽减少了无量纲与原始水翼相比，Q基准涡旋等值面面积（Q_面积= 2×10 ⁷）增加了5.13％，提升阻力比增加了17.02％。沟槽深度d和沟槽宽度w被证明对水翼能量性能有更大的影响。TLV和流动模式受不同BSG配置的影响很大，而更宽的BSG则导致TLV的面积减小，但以降低能源性能为代价。