Semi-analytical study of reduction of wave impact on an elastic plate in the presence of a vertical porous structure

Based on the small-amplitude water wave theory, the usefulness of a vertical porous structure extending from top to bottom of finite width to reduce the wave-induced hydrodynamics responses of an elastic plate that is floating freely on the free surface is studied. The fluid flow inside the porous structure is based on Sollitt and Cross model, and the elastic plate is modeled using the thin plate theory. A generalized code based on the eigenfunction expansion method is developed for solving the boundary value problem. Scattering coefficients and various hydrodynamic parameters related to the wave scattering, such as wave forces on the porous structure, free surface elevation, elastic plate deflection, shear force, and strain, are analyzed for various waves and structural parameters of porous structure and elastic plate. It is found that the values of the scattering coefficients are less with progressively increasing width and frictional coefficient of the porous structure. As more wave is dissipated by the porous structure with an increase in frictional coefficient, as a result, the free surface elevation, plate deflection, shear force, and strain decrease with an increase in frictional coefficient. Moreover, with the distance between the porous structure and the elastic plate, the scattering coefficients and forces on the porous structure follow a periodic and oscillatory pattern. This model is expected to be of great help in protecting different coastal assets.