Wave interactions with perforated breakwater

The present paper describes a theoretical analysis and an associated numeri cal model used to assess the performance of a breakwater consisting of a pe rforated front wall, an impermeable back wall, and a rock-filled core. The numerical method is based on an eigenfunction expansion and utilizes a boun dary condition at the perforated wall that accounts for energy dissipation. The numerical model is validated by comparison with previous numerical stu dies of the limiting cases of a permeable seawall and a perforated breakwat er with an impermeable back wall. Relevant numerical results that are prese nted relate to the reflection coefficient, the wave runup, and the wave for ce. The effects of porosity, breakwater geometry, and relative wavelength a re discussed; the choice of suitable parameters needed to model the permeab ility of the breakwater is described; and an example application to a pract ical design situation is given.