Impact of a vertical porous barrier in the reflection of water waves and mitigation of wave forces on a rigid floating structure in the presence of an elevated bottom and a trench

Abstract

This study deals with an oblique wave interaction by a floating rigid rectangular structure in the presence of a porous barrier which is placed in front of the floating structure. By considering the bottom topography as an elevated-type and a trench-type bottom, it is assumed that the train of water waves interacts with the porous barrier and the floating structure due to which it undergoes partial reflection. The boundary value problem in the fluid domain, which is split into five sub-regions, is solved by the utilization of separation of variables technique and eigenfunction expansion. The impact of the porous barrier and bottom topography on the reflection coefficient and hydrodynamic forces acting on the floating structure is discussed. As the distance of the porous barrier from the floating structure increases, an oscillatory pattern in the reflection coefficient is observed. Further, when the height of the elevated bottom or trench-bottom increases, the reflection coefficient increases in both cases; the reflection is higher in the presence of a trench than that due to the elevated sea-bed. The obtained results are validated against an established result which shows a very close match.