ABSTRACT The wave transformation due to the presence of stratified porous structure lying on flat seabed, elevated seabed, and stepped seabed is analyzed under the oblique wave incidence. The stratified porous structure in the absence and presence of the leeward wall along with the confined region is examined using the matched eigenfunction expansion technique. The direct analytical relations are obtained to examine the wave transformation for the case of long-wave approximations for multilayered porous structure lying on various types of seabed. The wave reflection coefficient, transmission coefficient, energy damping, and wave force on the vertical wall in the presence of stratified porous block are analyzed with variation in the sea-bed characteristics, porosity, friction factor, structural width, and water chamber length. The study shows that the energy damping increases with the increase in the porosity of the seaside porous layer due to the presence of high void spaces. Further, the stratified porous structure shows a considerable impact in decreasing the resonating peaks and troughs for the wave force acting on the seawall. In addition, the stepped seabed is observed to reduce the wave force on the leeward wall as compared with the uniform and elevated seabed in the presence of stratified porous block.

中文翻译：

---

层状多孔块存在下海床特征对波浪变换的意义

摘要 分析了在斜波入射情况下，由于位于平坦海床、高架海床和阶梯海床的分层多孔结构的存在而引起的波浪变换。使用匹配的本征函数扩展技术检查在不存在和存在背风壁以及受限区域的情况下的分层多孔结构。获得了直接解析关系以检查位于各种类型海床上的多层多孔结构的长波近似情况下的波浪变换。分析了存在分层多孔块时垂直壁面的波浪反射系数、透射系数、能量阻尼和波浪力随海床特征、孔隙度、摩擦系数、结构宽度和水室长度的变化。研究表明，由于高空隙空间的存在，能量阻尼随着海边多孔层孔隙率的增加而增加。此外，分层多孔结构对降低作用在海堤上的波浪力的共振波峰和波谷有相当大的影响。此外，在分层多孔块存在的情况下，与均匀和升高的海床相比，阶梯状海床减少了背风壁上的波浪力。