Scattering of oblique water waves by thick porous structure and thin elastic plate

Abstract

The present study deals with the usefulness of the partial porous structure of finite width placed at a finite distance from the elastic plate to mitigate the hydrodynamic response of the elastic plate. Two different configurations of the porous structure namely bottom-standing and surface-piercing structures are analyzed. The elastic plate is modeled using thin plate theory, and the wave past the thick porous structure is based on Sollitt and Cross model, the problems are investigated based on the small-amplitude water wave theory in water of finite depth. With the aid of the eigenfunction expansion method, the associated boundary value problem is reduced to a system of linear algebraic equations, which is solved numerically. For both configurations, the effects of various system parameters such as wavenumber and angle of incidence are analyzed. The impacts of structural parameters such as length, width of the porous structure, porosity are investigated from the graphs plotted on the reflection coefficient, transmission coefficient and dissipation coefficient and hydrodynamic forces. Further, detailed analysis on free surface elevation, elastic plate deflection, shear force and strain is presented. The study reveals that with an increase in length, width, porosity, and friction factor of the porous structure the dissipation of wave energy increases which helps in diminishing the wave impact on the elastic plate.