Study On Hydrodynamic Coefficients Of Plate-Pontoon Type Breakwater

With the development of ocean engineering, great interest has been focused on floating breakwater for deep sea wave protecting problem because of its easy manufacturing and removing, low cost and excellent water exchange ability. As a new type device for deep sea application, the plate-pontoon type breakwater presented in this paper considered the real sea conditions. The hydrodynamic study of submerged plate-pontoon type breakwater and floating plate-pontoon type breakwater has been systematically investigated on the basis of wave radiation and diffraction theory and the boundary element method is utilized in numerical simulation. The influence of different parameters such as space between plate and pontoon, thickness of the pontoon on these two types breakwater is discussed. It is found that:(1) Submerged plate-pontoon type breakwater is efficient for mid-and-Long wave elimination. The space between plate and pontoon, thickness of the pontoon has weak influence on the reflection coefficient and transmission coefficient.(2) Floating plate-pontoon type breakwater is efficient for mid-and-short wave elimination. The space between plate and pontoon, thickness of the pontoon also has a weak influence on the reflection coefficient and transmission coefficient.(3) Both Submerged and Floating plate-pontoon type breakwater, the value of added mass and damping coefficient for heave is greater than the other two directions (sway and roll). But the space between plate and pontoon, thickness of the pontoon has more influence on the added mass and damping coefficient for sway and roll than that for heave.(4) When the submergence is small, the value of added mass for submerged plate-pontoon type breakwater is negative.