LAUSR

Abstract The interaction of Airy waves with a bottom-mounted surface-piercing concentric dual-arc porous wall was theoretically investigated in this study via the eigenfunction expansion approach. The outer and inner arc-shaped walls were considered to be thin in thickness and rigidly fixed on a flat seabed. As critical elements, two virtual concentric cylinders extending the dual-arc wall structure were introduced to divide the entire fluid domain into three major sub-domains. Subsequently, a set of linear equations of unknown coefficients in the velocity potential was derived and solved by matching the boundary conditions between different regions. The current results of the three cases were consistent with the literature reports. Moreover, the dual-arc wall delivered a better shielding performance than the single-arc wall. In addition, parametric studies on porosity, annular spacing, opening angle, and incident wave angle were given and discussed. Furthermore, the hydrodynamic loads and wave elevations for a concentric structure with an outer arc-shaped wall and a concentric two-cylinder structure were compared using the same parameters. The hydrodynamic performance of the two structures were found to be similar, which reveals that former structure can replace the latter in certain water areas.