The interaction of flexural-gravity waves with a submerged porous elliptic disk in deep water: Scattering and radiation analysis

In this paper, linear wave theory is applied to study the flexural-gravity wave radiation as well as scattering by a submerged porous elliptic disk in deep water with an ice-covered surface. The problems are transformed into two-dimensional hypersingular integral equations on the disk surface, which are then computed numerically via a spectral method. Numerical results are initially compared with published results for a porous circular disk. A detailed parametric analysis is then conducted for the porous elliptic disk. The main focus of this study is to examine how parameters such as submersion depth, disk geometry, and ice-cover flexibility affect various hydrodynamic parameters associated with wave radiation and scattering. The results indicate that porous elliptic disks exhibit reduced wave scattering and lower hydrodynamic forces compared to rigid disks. The presence of ice-cover significantly attenuates scattering energy. A notable shift in the pressure field around the disk occurs as it approaches the ice-cover, resulting in resonance effects. The elliptic shape, combined with variations in porosity and submersion depth, leads to profound changes in both the added mass and damping coefficient in radiation cases. Furthermore, the radiation analysis reveals critical shifts in the added mass and damping coefficients for non-circular bodies, particularly for large aspect ratios and submersion depths. All these factors indicate the importance of taking into account the effects of ice as well as geometric and material properties in the design of structures operating in cold marine environments.