Damping of Oblique Ocean Waves by a Vertical Porous Structure Placed on a Multi-step Bottom

倾斜的海浪由放在多步底部地形学上的垂直多孔的结构抑制在线性水波浪理论的帮助下被学习。倾斜的波浪的某部分，多孔的结构上的事件，变得被多步底部反映了，多孔的结构，和剩余的宣传进跟随多孔的结构的水媒介。二个盒子被考虑：在跟随多孔的结构然后跟随多孔的结构的无界的水媒介的一种特殊情况的水媒介从多孔的结构在有限距离放的第一面一稳固的垂直的墙。在两个盒子中，边界价值问题在三不同媒介被建立，是的第一媒介水，是的第二媒介由 p 组成的多孔的结构在每个步骤上面的垂直区域一个和是的第三媒介水再。由沿着 virtualvertical 边界使用匹配的条件，线性方程的一个系统被推出。思考系数和播送进步波浪的无尺寸的振幅的行为由于不同相关参数被学习。由于倾斜的水的繁殖，通过多孔的结构的波浪也是的精力损失执行了。各种各样的参数的效果例如迅速凋落的模式的数字，孔，磨擦因素，结构宽度，步骤和入射角的数字，在思考以后，系数和播送波浪的无尺寸的振幅为两个盒子图形地被学习。迅速凋落的模式的数字仅仅影响散布现象。但是孔表演的更高的价值相对为更低的孔比那降低思考。在思考系数的摆动为磨擦因素的更低的价值被观察，但是它随磨擦因素的价值的增加消失。播送进步波浪的振幅独立于结构的孔。但是磨擦因素的更低的价值引起更高的传动。调查然后为第二个盒子被执行，即，当墙是不在的时。这里考虑的二个盒子之间的重要差别是思考由于薄多孔的结构很高稳固的墙什么时候作为与盒子相比存在没有墙什么时候是在场的。精力损失也由于不同的孔，磨擦因素，结构宽度和入射角被检验。我们的模型的有效性被与可得到的匹配它查明。

Oblique ocean wave damping by a vertical porous structure placed on a multi-step bottom topography is studied with the help of linear water wave theory. Some portion of the oblique wave, incident on the porous structure, gets reflected by the multi-step bottom and the porous structure, and the rest propagates into the water medium following the porous structure. Two cases are considered： first a solid vertical wall placed at a finite distance from the porous structure in the water medium following the porous structure and then a special case of an unbounded water medium following the porous structure. In both cases, boundary value problems are set up in three different media, the first medium being water, the second medium being the porous structure consisting ofp vertical regions-one above each step and the third medium being water again. By using the matching conditions along the virtualvertical boundaries, a system of linear equations is deduced. The behavior of the reflection coefficient and the dimensionless amplitude of the transmitted progressive wave due to different relevant parameters are studied. Energy loss due to the propagation of oblique water wave through the porous structure is also carried out. The effects of various parameters, such as number of evanescent modes, porosity, friction factor, structure width, number of steps and angle of incidence, on the reflection coefficient and the dimensionless amplitude of the transmitted wave are studied graphically for both cases. Number of evanescent modes merely affects the scattering phenomenon. But higher values of porosity show relatively lower reflection than that for lower porosity. Oscillation in the reflection coefficient is observed for lower values of friction factor but it disappears with an increase in the value of friction factor. Amplitude of the transmitted progressive wave is independent of the porosity of the structure. But lower value of friction factor causes higher transmission. The investigation is then carried out for the second case, i.e., when the wall is absent. The significant difference between the two cases considered here is that the reflection due to a thin porous structure is very high when the solid wall exists as compared to the case when no wall is present. Energy loss due to different porosity, friction factor, structure width and angle of incidence is also examined. Validity of our model is ascertained by matching it with an available one.