The paper reports a numerical investigation into the effect of rubble mounds inside perforated caisson breakwaters (PCBs), in which a line-shaped mass source wavemaker is proposed for generating random waves. A series of experiments are employed to validate the numerical model, and good agreements are observed in the comparison of the experimental and numerical results. With the use of the validated numerical model, the numerical investigation is performed, in which the attention is mainly paid to two parameters: the slope angle and porosity of the inner rubble mound. The result shows that, as the slope angle of the inner rubble mound increases, the reflection coefficient is observed to decrease first and then increase, and compared to the experiment, both the positive and negative hydrodynamic pressure acting on the solid rear wall of PCBs is weakened. On the other hand, although a larger inner rubble mound porosity is beneficial to diminish the reflection coefficient, the reduction is not obvious especially when the front wall porosity is small. Furthermore, as the increase of front wall porosity and relative wave absorption chamber length (the ratio of wave absorption chamber length to significant wavelength), the effect of the slope angle and porosity of the inner rubble mound becomes more significant because more waves could enter the wave absorption chamber. The relative wave absorption chamber length considered in the present study ranges from 0.06 to 0.21, and the recommended slope angle is approximately 45 degrees.

该论文报告了对穿孔沉箱防波堤 (PCB) 内碎石堆影响的数值研究，其中提出了一种线形质量源造波器来产生随机波。一系列实验被用来验证数值模型，在实验和数值结果的比较中观察到良好的一致性。利用经过验证的数值模型进行数值研究，主要关注两个参数：坡角和内部碎石丘的孔隙度。结果表明，随着内部碎石堆坡角的增大，观察到反射系数先减小后增大，与实验相比，作用在 PCB 实心后壁上的正负流体动压都减弱了。另一方面，虽然较大的内部碎石丘孔隙度有利于减小反射系数，但减小并不明显，尤其是前壁孔隙度较小时。此外，随着前壁孔隙度和相对吸波室长度（吸波室长度与有效波长之比）的增加，内部碎石丘的倾斜角和孔隙度的影响变得更加显着，因为更多的波可以进入吸波室。本研究中考虑的相对吸波室长度范围为 0.06 至 0.21，推荐的倾斜角约为 45 度。虽然较大的内部碎石丘孔隙度有利于减小反射系数，但减小并不明显，尤其是前壁孔隙度较小时。此外，随着前壁孔隙度和相对吸波室长度（吸波室长度与有效波长之比）的增加，内部碎石丘的倾斜角和孔隙度的影响变得更加显着，因为更多的波可以进入吸波室。本研究中考虑的相对吸波室长度范围为 0.06 至 0.21，推荐的倾斜角约为 45 度。虽然较大的内部碎石丘孔隙度有利于减小反射系数，但减小并不明显，尤其是前壁孔隙度较小时。此外，随着前壁孔隙度和相对吸波室长度（吸波室长度与有效波长之比）的增加，内部碎石丘的倾斜角和孔隙度的影响变得更加显着，因为更多的波可以进入吸波室。本研究中考虑的相对吸波室长度范围为 0.06 至 0.21，推荐的倾斜角约为 45 度。随着前壁孔隙度和相对吸波室长度（吸波室长度与有效波长之比）的增加，内部碎石丘的倾斜角和孔隙率的影响变得更加显着，因为更多的波可以进入吸波室。本研究中考虑的相对吸波室长度范围为 0.06 至 0.21，推荐的倾斜角约为 45 度。随着前壁孔隙度和相对吸波室长度（吸波室长度与有效波长之比）的增加，内部碎石丘的倾斜角和孔隙度的影响变得更加显着，因为更多的波可以进入吸波室。本研究中考虑的相对吸波室长度范围为 0.06 至 0.21，推荐的倾斜角约为 45 度。