ABSTRACT

The scattering of surface gravity waves by a skirt wall breakwater is analysed in two dimensions under the assumption of small-amplitude wave theory. The oscillatory wave past the porous skirt walls is assumed to follow Darcy’s law. The boundary value problem is solved using multi-domain boundary element method to obtain the numerical results for the different number of porous skirt walls, relative pontoon width, relative submergence and different porosity of the skirt walls. The study reveals that an increase in the number of skirt walls from one to four can reduce the wave transmission by 61% but at the expense of an increase in horizontal wave force by 90% and decrease in the vertical force by 31%. A minimum of two-skirt walls is needed for reducing wave transmission. Skirt wall porosity of 0.40 is recommended for field applications considering the trade-off between the wave transmission and wave forces.

摘要

在小振幅波理论的假设下，对裙墙防波堤对地表重力波的散射进行了二维分析。假定通过多孔裙壁的振荡波遵循达西定律。采用多域边界元法求解边值问题，得到了不同多孔裙壁数量、相对浮筒宽度、相对淹没度和不同孔隙率的裙壁数值结果。研究表明，裙墙数量从 1 个增加到 4 个可以减少 61% 的波传输，但代价是水平波力增加 90%，垂直力减少 31%。至少需要两层裙墙来减少波传输。裙壁孔隙率为0。