Abstract REEFS is a novel multipurpose patented wave energy converter (WEC) that combines electric energy production with shore protection. The device shows some similarities with natural reefs and detached submerged breakwaters. However, unlike previous ones it is installed with an orthogonal alignment relative to coast line and with a greater freeboard. Exterior stay vanes, are another distinct characteristic of the device. Therefore, the REEFS differentiating functionality of shore protection cannot be directly extrapolated from detached submerged breakwater studies and the effective energy dissipation capacity of this new WEC taking into account its specific characteristics should be investigated. In this article an experimental investigation of the energy dissipation potential of REEFS WEC was implemented. A small scale physical model (1.5:100) was installed in a piston wavemaker flume and tested under regular wave conditions established by applying Froude similarity to typical West Portuguese sea state conditions. Resistive wave gauges were installed upstream and downstream the device, in order to record water level time series. Discrete Fourier transform technique was used to compute the wave energy spectra (WES). Energy dissipation was evaluated by comparing upstream and downstream WES. Two versions of the device were tested: i) without exterior stay vanes; ii) with exterior stay vanes. Regardless of the version, the REEFS model proved to be able to dissipate part of the incident wave energy. This capacity exhibited a dependence on the wave period, globally decreasing as the wave period increased. The version equipped with stay vanes always exhibited a substantially higher energy dissipation. From a relative point of view, stay vanes showed to be more important for long waves. REEFS energy dissipation was not far from the inferior values reported in literature review for submerged breakwaters of comparable dimensions, confirming the expectations about its shore protection functionality.

中文翻译：

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新型REEFS波浪能转换器护岸潜力的实验评价

摘要 REEFS 是一种新型的多用途专利波浪能转换器（WEC），将电能生产与海岸保护相结合。该装置与天然珊瑚礁和独立的水下防波堤有一些相似之处。然而，与以前的不同，它的安装与海岸线垂直对齐，并具有更大的干舷。外撑叶片是该装置的另一个明显特征。因此，海岸保护的 REEFS 差异化功能不能直接从独立的淹没式防波堤研究中推断出来，应该研究考虑到其特定特性的新 WEC 的有效能量耗散能力。在本文中，对 REEFS WEC 的能量耗散潜力进行了实验研究。一个小比例的物理模型（1.5：100) 安装在活塞造波器水槽中，并在通过将 Froude 相似性应用于典型的西葡萄牙海况条件而建立的规则波浪条件下进行测试。电阻波计安装在装置的上游和下游，以记录水位时间序列。离散傅立叶变换技术用于计算波能谱（WES）。通过比较上游和下游 WES 来评估能量耗散。测试了该装置的两个版本：i) 没有外部撑杆；ii) 带有外部支撑叶片。无论版本如何，REEFS 模型都证明能够消散部分入射波能量。这种能力表现出对波浪周期的依赖性，随着波浪周期的增加而整体下降。配备撑杆的版本总是表现出明显更高的能量耗散。从相对的角度来看，拉力叶片对长波更重要。REEFS 能量耗散与文献综述中报告的具有可比尺寸的水下防波堤的较差值相差不远，证实了对其海岸保护功能的期望。