Abstract Experimental investigations measuring both bed elevation changes and near-structure flow velocities were undertaken to investigate wave scour processes around a model Oscillating Water Column (OWC) Wave Energy Converter (WEC) for a range of incident wave conditions at approximately 1:20 scale. The experiment design was informed by a proposed 200 kW OWC WEC deployment site at King Island, Australia. The measurements provide the first experimental data on scour around an OWC WEC structure, and one of the most comprehensive experimental studies of wave scour around a large rectangular cross-section structure. High resolution scour erosion and deposition patterns were measured using an above-water laser-based system. For normally incident waves, scour holes were observed to develop on all four corners, and the size of the scour holes at the four corners increased with the Keulegan-Carpenter (KC) number. An additional scour hole/trench also formed along the upstream face of the OWC WEC due to the flow in/out of the OWC WEC internal chamber. Changing the incident wave propagation angle by 20° has a significant effect on the observed scour patterns, with reduced scour on the front and back corners but significant scour holes remaining on the other two corners. It is found that if the model is not sufficiently embedded into the sediment bed, scour can undermine a significant area under the structure, with quadrant shaped scour holes underneath the back corners extending to approximately 25% of the total base area, suggesting a risk of differential settlement in field conditions.

中文翻译：

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基于重力的振荡水柱波能转换器周围 3D 冲刷过程的实验研究

摘要 进行了测量河床高程变化和近结构流速的实验研究，以研究模型振荡水柱 (OWC) 波浪能转换器 (WEC) 周围的波浪冲刷过程，适用于大约 1:20 比例的一系列入射波浪条件。澳大利亚国王岛拟建的 200 kW OWC WEC 部署地点为实验设计提供了依据。这些测量提供了关于 OWC WEC 结构周围冲刷的第一个实验数据，也是对大型矩形横截面结构周围波浪冲刷的最全面的实验研究之一。使用基于水上激光的系统测量高分辨率冲刷侵蚀和沉积模式。对于正常入射波，观察到在所有四个角都形成冲刷孔，四个角的冲刷孔的大小随着 Keulegan-Carpenter (KC) 数的增加而增加。由于流入/流出 OWC WEC 内室，沿 OWC WEC 的上游面也形成了一个额外的冲刷孔/沟槽。将入射波传播角改变 20° 对观察到的冲刷模式有显着影响，前角和后角的冲刷减少，但在其他两个角上保留了显着的冲刷孔。发现如果模型没有充分嵌入沉积床，冲刷会破坏结构下的一个重要区域，后角下方的象限形冲刷孔延伸到总基部面积的大约 25%，表明存在风险现场条件下的差异沉降。由于流入/流出 OWC WEC 内室，沿 OWC WEC 的上游面也形成了一个额外的冲刷孔/沟槽。将入射波传播角度改变 20° 对观察到的冲刷模式有显着影响，前后角上的冲刷减少，但其他两个角上仍留有明显的冲刷孔。发现如果模型没有充分嵌入沉积床，冲刷会破坏结构下的一个重要区域，后角下方的象限形冲刷孔延伸到总基部面积的大约 25%，表明存在风险现场条件下的差异沉降。由于流入/流出 OWC WEC 内室，沿 OWC WEC 的上游面也形成了一个额外的冲刷孔/沟槽。将入射波传播角改变 20° 对观察到的冲刷模式有显着影响，前角和后角的冲刷减少，但在其他两个角上保留了显着的冲刷孔。发现如果模型没有充分嵌入沉积床，冲刷会破坏结构下的一个重要区域，后角下方的象限形冲刷孔延伸到总基部面积的大约 25%，表明存在风险现场条件下的差异沉降。将入射波传播角改变 20° 对观察到的冲刷模式有显着影响，前角和后角的冲刷减少，但在其他两个角上保留了显着的冲刷孔。发现如果模型没有充分嵌入沉积床，冲刷会破坏结构下的一个重要区域，后角下方的象限形冲刷孔延伸到总基部面积的大约 25%，表明存在风险现场条件下的差异沉降。将入射波传播角改变 20° 对观察到的冲刷模式有显着影响，前角和后角的冲刷减少，但在其他两个角上保留了显着的冲刷孔。发现如果模型没有充分嵌入沉积床，冲刷会破坏结构下的一个重要区域，后角下方的象限形冲刷孔延伸到总基部面积的大约 25%，表明存在风险现场条件下的差异沉降。