Wave attenuation by floating and submerged porous elastic plates under oblique wave incidence

An analytical framework is developed to investigate oblique wave scattering by floating and submerged porous elastic plates within the context of linearized water wave theory. The complex dispersion relation governing the wave–structure interaction is examined in detail, and the nature of its roots is identified through a combination of the argument principle and contour plotting techniques. The resulting boundary-value problem is solved using the eigenfunction expansion method. Reflection, transmission, and energy dissipation coefficients, together with their corresponding surface plots, are computed to elucidate the influence of key wave and structural parameters on the formation of a tranquil wave zone. The free-surface elevation and deflection of both floating and submerged plates are also investigated. The results demonstrate that the presence of porous plates significantly reduces wave reflection while enhancing energy dissipation, highlighting the effectiveness of porosity in attenuating wave motion. A similar trend is observed with increasing submergence depth of the plate, which further promotes wave energy dissipation. In contrast, an increase in the incident wave angle and plate rigidity leads to a reduction in dissipated energy, indicating a diminished damping capability under such conditions. Overall, the study reveals that floating and submerged porous elastic plates are highly efficient in dissipating wave energy, resulting in substantially lower levels of wave reflection and transmission. These findings provide valuable theoretical insight for the design of coastal and offshore structures aimed at wave attenuation and energy dissipation.