Reservoir sedimentation is a long-term process with various risks, such as reduction of storage capacity, hydropower generation and flood control functions throughout a reservoir's lifespan. For reservoirs facing loss of function with severe deposition, sediment flushing is an approach to preserving long-term storage. Here, submerged vanes combined with pressure flushing operations are proposed to facilitate scouring of such deposition. Experiments with various submerged vane heights, inclination angles on the flow direction, spacing, and divergent and convergent arrangements were conducted to investigate the scour cone volume and removal efficiency. Results showed that two divergent submerged vanes at an angle of 20° on the flow direction and optimum vane spacing ratios removed the deposited sediment significantly. In the presence of the submerged vanes, final sediment flushing volume and efficiency increased by a factor of 48 compared to the reference test. Using the experimental results, three equations were proposed to estimate the scour cone dimensions (length, width and depth). Additionally, a non-dimensional equation was developed for estimating the scour cone volume, using a polynomial correlation with vane spacing. The results of this study recommend the best installation of submerged vanes for releasing deposited sediments in the region near the bottom outlets of reservoirs.

中文翻译：

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圆形水库进水口前沉水叶片对冲沙锥的影响

水库淤积是一个长期的过程，在水库的整个生命周期中存在着各种风险，例如库容下降、水力发电和防洪功能下降。对于面临严重淤积功能丧失的水库，冲沙是一种长期保存的方法。在这里，建议将浸入式叶片与压力冲洗操作相结合，以促进这种沉积物的冲刷。对各种浸入式叶片高度、流动方向的倾斜角、间距以及发散和会聚布置进行了实验，以研究冲刷锥体积和去除效率。结果表明，在流动方向上成20°角的两个发散的水下叶片和最佳的叶片间距比可以显着去除沉积的沉积物。在存在水下叶片的情况下，与参考测试相比，最终的沉积物冲洗量和效率提高了 48 倍。使用实验结果，提出了三个方程来估计冲刷锥尺寸（长度、宽度和深度）。此外，开发了一个无量纲方程来估计冲刷锥体积，使用与叶片间距的多项式相关。这项研究的结果建议最好安装水下叶片，以释放靠近水库底部出口区域的沉积物。开发了一个无量纲方程来估计冲刷锥体积，使用与叶片间距的多项式相关。这项研究的结果建议最好安装水下叶片，以释放靠近水库底部出口区域的沉积物。开发了一个无量纲方程来估计冲刷锥体积，使用与叶片间距的多项式相关。这项研究的结果建议最好安装水下叶片，以释放靠近水库底部出口区域的沉积物。