Motion Response and Wave Attenuation of Linked Floating Breakwaters

Abstract

A mathematical model has been developed for the motion response and wave attenuation of two linked floating breakwaters moored to the ocean floor. The two‐body interaction problem is divided into a hydrodynamic problem and a motion response problem. The hydrodynamic problem deals with the calculation of the wave‐exciting, added mass, and damping forces on the two bodies induced by incident regular waves and the waves caused by the motion of the bodies. The motion response problem considers a mechanical system subjected to the harmonic hydrodynamic forces and restrained by the mooring lines and the elastic links between the two bodies. The mathematical model has been programmed using a three‐dimensional finite element technique. The numerical model accounts for all three‐dimensional effects, including the incidence of oblique waves, the interaction of the two breakwaters, their finite length‐to‐width ratio, the finite water depth, and the proximity of solid boundaries. Both frequency‐domain (linear) and time‐domain (nonlinear) solutions of the breakwater motion can be obtained. The results of example calculations are presented to demonstrate the use of the numerical model.