Wave Interactions with Perforated Breakwater

Abstract

The present paper describes a theoretical analysis and an associated numerical model used to assess the performance of a breakwater consisting of a perforated front wall, an impermeable back wall, and a rock-filled core. The numerical method is based on an eigenfunction expansion and utilizes a boundary condition at the perforated wall that accounts for energy dissipation. The numerical model is validated by comparison with previous numerical studies of the limiting cases of a permeable seawall and a perforated breakwater with an impermeable back wall. Relevant numerical results that are presented relate to the reflection coefficient, the wave runup, and the wave force. The effects of porosity, breakwater geometry, and relative wavelength are discussed; the choice of suitable parameters needed to model the permeability of the breakwater is described; and an example application to a practical design situation is given.