Abstract The hydrodynamic forces on the stationary partially submerged cylinder are investigated through towing test with Reynolds number ranging from 5 × 104 to 9 × 105. Three test groups of partially submerged cylinders with submerged depths of 0.25 D, 0.50 D, and 0.75 D and one validation group of fully submerged cylinders are conducted. During the experiments, the hydrodynamic forces on the cylinders are measured using force sensors. The test results show a considerable difference in the hydrodynamic coefficients for the partially submerged cylinders versus the fully submerged cylinders. A significant mean downward lift force is first observed for the partially submerged cylinders in a steady flow. The maximum of the mean lift coefficients can reach 1.5. Two distinct features are observed due to the effects of overtopping: random distributions in the mean drag coefficients and a clear quadratic relationship between the mean lift coefficients and the Froude number appear in the non-overtopping region. However, the novel phenomenon of a good linear relationship with the Froude number for the mean hydrodynamic coefficients is clearly shown in the overtopping region. In addition, fluctuating hydrodynamic coefficients are further proposed and investigated. These results are helpful to have a better understanding of the problem and to improve related structural designs.

中文翻译：

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稳定流动中高雷诺数下部分浸没圆柱体上的水动力

摘要 通过雷诺数为5×104～9×105的拖曳试验研究了静止部分浸没圆筒上的水动力。3组浸没深度为0.25D、0.50D和0.75D的部分浸没圆筒和一个进行了完全浸没气瓶的验证组。在实验过程中，使用力传感器测量气缸上的流体动力。测试结果表明，部分浸入式气缸与完全浸入式气缸的流体动力系数存在显着差异。对于稳定流动中部分浸没的圆柱体，首先观察到显着的平均向下升力。平均升力系数的最大值可以达到1.5。由于过顶的影响，观察到两个不同的特征：平均阻力系数的随机分布以及平均升力系数与弗劳德数之间的明显二次关系出现在非覆盖区域。然而，与平均水动力系数的弗劳德数具有良好线性关系的新现象在越顶区域清楚地显示出来。此外，进一步提出和研究了波动的水动力系数。这些结果有助于更好地理解问题并改进相关的结构设计。与平均水动力系数的弗劳德数具有良好线性关系的新现象在越过区域清楚地显示出来。此外，进一步提出和研究了波动的水动力系数。这些结果有助于更好地理解问题并改进相关的结构设计。与平均水动力系数的弗劳德数具有良好线性关系的新现象在越过区域清楚地显示出来。此外，进一步提出和研究了波动的水动力系数。这些结果有助于更好地理解问题并改进相关的结构设计。