Performance of a floating breakwater by the use of wave slamming loss

A new type of floating breakwater, mainly using the wave dissipation mechanism caused by wave slamming to a bundle of cylindrical members near the water surface as developed. It aims attenuation of both reflected and transmitted waves about the floating breakwater. Model tests show that the basic model of floating breakwaters, which consists of a bundle of horizontal circular cylinders and rectangular floating unit at both ends of the cylinders, is not sufficient to reduce transmitted waves compared to the conventional pontoon-type floating breakwater. To activate the wave energy dissipation due to the wave slamming, various improvements, such as additions of footing plates and vertical thin plates to the basic model, were extensively examined. It was seen that the improved floating breakwater is very effective to reduce both reflected and transmitted waves for comparatively short waves. The numerical analysis based on the wave source distribution method was employed to theoretically examine the wave transmission and reflection characteristics about the floating breakwater. In the analysis, the damping wave theory was used to partly account for the wave energy loss caused by the wave slamming phenomena.