This study focuses on the formulation of a spectral approach to obtain the transmission coefficient (Ct ) of floating breakwaters (FB) in irregular waves based on Ct in regular waves. Additionally, it provides a performance comparison of two quite similar rectangular and circular pontoons as FB. It starts with the comparison of Ct and extends to motions in regular waves by experiment. Overall, the rectangular section showed better performance for both Ct and motions. The spectral approach is formulated and validated. A parametric study on the performance of rectangular and circular FBs has been conducted by applying large scale physical modelling. The study shows that the rectangular section has considerably better performance than the circular section in almost all irregular waves. It is concluded that the spectral approach for irregular waves is a comprehensive method. It is also easy for implementation having FB performances in a limited number of regular waves.

中文翻译：

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基于规则波浪实验的光谱法比较两个类似浮筒作为浮动防波堤的性能

本研究的重点是基于规则波浪中的 Ct 制定一种光谱方法，以获得不规则波浪中浮动防波堤 (FB) 的透射系数 (Ct)。此外，它还提供了与 FB 非常相似的两个矩形和圆形浮筒的性能比较。它从Ct的比较开始，通过实验扩展到规则波中的运动。总体而言，矩形截面在 Ct 和运动方面表现出更好的性能。谱方法被制定和验证。通过应用大规模物理建模，对矩形和圆形 FB 的性能进行了参数研究。研究表明，矩形截面在几乎所有不规则波浪中都比圆形截面具有明显更好的性能。结论是不规则波的谱方法是一种综合方法。在有限数量的规则波中具有FB性能的实现也很容易。