Hydrodynamic Efficiency of a New Design of Half-Submerged Breakwater Compared to a Rectangular Caisson

In this paper, the wave transmission, reflection, and energy dissipation characteristics as well as the hydrodynamic forces of two partially submerged breakwaters are compared. The breakwaters under consideration are designed to be installed in coastal areas where the water depth may be important (typically 50 m), making traditional bottom seated configurations unsuitable. They are composed of a free-surface piercing caisson mounted on vertical piles. The first breakwater considered in this study, as a matter of reference for comparison, is a rectangular caisson. The second one is a new profile proposed by Colmard and called BYBOP by the writer. The seaside face, fronting the ocean, is an elliptic profile while the harbor side is a plane inclined 55° to the vertical. A numerical simulation on both these shapes, at model scale, was carried out in two numerical wave tanks. The first one, CANAL, is based on fully nonlinear potential flow theory while the second one, ICARE, is a Reynolds averaged Navier–Stoke...