Wave response of a novel breakwater concept with oscillating water columns

A novel concept of a mega floating breakwater-windbreak is proposed for reducing both wave height and wind speed on its leeward side. L-shaped internal channels are installed inside the breakwater hull that surface from the floating breakwater as tubes that function like “trees” to break the wind. The channel openings are on the vertical walls at the upstream side of the breakwater, so that water is allowed to oscillate inside the channels and create extra viscous damping. Numerical studies using both linear boundary element method and CFD were carried out to determine the wave transmissibility and wave force on the breakwater with and without the internal channels. The wave condition in the Gold Coast, Australia was selected as an environmental input. Operating wave condition and extreme wave condition were separately investigated. Scaled dimensions were used to study the breakwater behavior in a wave flume. The results show that when water oscillates inside the channels, the transmitted wave height and lateral wave force acting on the breakwater will be reduced. In addition, since the viscous effect influences waves of all lengths, the internal channels improves the breakwater performance in blocking long waves