Interaction between oblique waves and multiple bottom-standing flexible porous barriers near a rigid wall

Abstract

The interaction between oblique surface waves and multiple bottom-standing flexible porous barriers under the combined effects of a neighboring rigid vertical wall and a step of arbitrary profile on the bottom is investigated. The problem is analyzed under the assumptions of small-amplitude water waves and structural response. The solutions are found using the methods of least-squares approximation, eigenfunction expansion and multi-mode approximation associated with the modified mild-slope equation. To keep the barriers at a desired position of interest, clamped-free or clamped-moored edge conditions are considered. Effects of various wave and structural parameters are studied for single, double and multiple barriers by looking into the reflection coefficient, wave force exerted on the rigid wall, free-surface elevations, and plate deflection of the barriers. The model is validated by comparing with results available in the literature for the special case of wave interaction with single and double rigid porous barriers near a rigid wall in the presence of a vertical step. The study reveals that the presence of multiple flexible porous barriers may effectively reduce the wave reflection and wave force exerted on the rigid wall. Further, full and nearly zero wave reflection can be found in the case of single and/or multiple barriers.