Wave diffraction from an array of porous cylinders with porous plates fixed inside

The interaction between water wave and an array of porous cylinders with porous plates fixed inside is investigated theoretically in this study. The porous cylinders are bottom-mounted and surface-piercing, which contain porous plates fixed below the free water surface. The analytical solution of velocity potential in the flow field is derived using eigenfunction expansion and Graf’s addition theorem for Bessel functions under the assumptions of potential flow theory and linear wave theory. This paper focus on investigating the influence of the porous plates on the diffraction process of the multiple porous cylinders. The results show that the existence of the porous plates has little effect on the surge force of the porous cylinders, but it can reduce the wave run up inside the cylinders. The behavior of the porous plates and porous cylinders in combination is similar to that of a wave absorber, which may cause a setdown of the free surface elevation on the array’s downstream side.