Wave attenuation and amplification by an abreast pair of floating parabolic breakwaters

An abreast pair of floating parabolic breakwaters is proposed as part of a breakwater-WEC (wave energy converter) hybrid system. An objective is providing a basis for tackling the problem of unreasonable shape while applying an isolated parabolic breakwater along a long shore. The other is providing multiple wave amplification chambers for the WECs. Wave attenuation and amplification are investigated using an open-source code HAMS. The effects of gap length and connection manner between the two parts in the pair are analyzed. Results show that for non-zero gap length, the application of a rigid connection slightly improves the wave attenuation by increasing the area of the low wave region on its lee side and greatly improves the wave amplification by increasing the area of the high wave amplification region on the weather side. An increase in the gap length intensifies the separation of low and high wave regions on the lee side by increasing both their areas, whereas it has negligible influence on the wave amplification. The worst wave amplification is obtained for rigidly connected breakwaters with no gap in between. A small gap is therefore recommended to be retained to improve the wave amplification without damaging the wave attenuation.