Mitigation of Wave Impact on Sea Wall by a Floating Elastic Plate and a Porous Structure

Abstract

The purpose of the present study is to reduce the high wave load on a sea wall by utilizing an elastic plate (EP) kept at fixed distance from a porous structure (PS). Thin plate theory is used to model the flow past EP, while Sollit and Cross theory is used to model the flow past PS. A linear potential theory-based analytical solution to the current problem is developed using the eigenfunction expansion technique. To understand the effect of PS and EP in creating tranquility zone and minimum wave loads on the rigid wall, horizontal wave force on the wall, reflection coefficient, dissipation coefficient and free surface elevation are computed and analyzed for different values of width and friction factor of PS, flexural rigidity and length of EP, angle of incidence, and distance between PS and EP, and the distance between EP and rigid wall. The study demonstrates that both structures considerably reduce the stress on the rigid wall and the wave reflection. It is found that the force on the wall shifted to the left as the width and frictional factor of PS increased. It is observed that PS effectively minimises the free surface elevation in the region between EP and the wall. It is also found that an effective tranquility zone may be produced, which will put less wave force on the rigid wall, with sufficient spacing between PS and EP, and EP and wall. The given model is expected to assist in preserving various coastal assets significantly.