Abstract In this paper, hydrodynamic characteristics of two-dimensional submerged breakwaters in water of finite depth and infinite domain interacting with sinusoidal waves are studied from both analytical and numerical approaches. Added mass and damping coefficients are obtained following the determination of radiation potentials in three degrees of freedom (sway, heave and roll). Diffraction problem is then solved according to the linear wave theory and the resulting forces are derived. To verify the results, a comparison of the solution from the analytical method with those obtained by the boundary element method is made and a good agreement is observed. Additionally, high aspect ratio horizontal and vertical flat submerged breakwaters are proposed and their hydrodynamic characteristics are analysed using the numerical and analytical methods. Results show that the horizontal flat submerged breakwater generates low transmitted waves. However, the vertical flat submerged breakwater transmits almost the entire incident wave energy. A parametric study on the effect of submergence depth and the width of the structure on the maximum diffraction wave amplitude, which is responsible for the transmitted wave energy, is carried out and a better understanding of the variation of diffraction wave amplitudes with respect to dominant parameters and wave frequency is achieved.

中文翻译：

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大纵横比矩形水下防波堤上的衍射波

摘要 本文从解析和数值方法研究了有限深度和无限域水中二维淹没式防波堤与正弦波相互作用的水动力特性。在确定三个自由度（摇摆、升沉和滚动）的辐射势之后，获得附加质量和阻尼系数。然后根据线性波理论解决衍射问题并导出合力。为了验证结果，将解析法的解与边界元法的解进行了比较，观察到了良好的一致性。此外，提出了高纵横比水平和垂直平坦的淹没式防波堤，并使用数值和解析方法分析了它们的水动力特性。结果表明水平平坦的淹没式防波堤产生低透射波。然而，垂直平坦的淹没式防波堤几乎传输了全部入射波能量。对淹没深度和结构宽度对最大衍射波振幅的影响进行了参数研究，最大衍射波振幅负责传输波能量，并更好地理解衍射波振幅相对于主要参数的变化并达到波频率。