An experimental study on hydrodynamic performance of a box-floating breakwater in different terrains

An experimental investigation on the hydrodynamic performance of a box-floating breakwater in different terrains is performed in a 2D wave flume under regular wave actions and irregular wave actions, respectively. The wave transmission coefficients, motion responses and mooring forces are focused to validate the hydrodynamic performance of the box-floating breakwater. The performance of the box-floating breakwater in flat terrain is also experimentally investigated for comparison. The influences of the terrain width and quantity on the hydrodynamic behaviors of the box-floating breakwater are discussed and analyzed. The results indicate that the box-floating breakwater in different terrains has a better wave attenuating ability than the box-floating breakwater in flat terrain due to wave energy loss caused by the interaction between the breakwater and terrain. However, the width of terrain has a limited effect on the hydrodynamic performance of the floating breakwater. For double terrains, the wave attenuation performance of the box-type floating breakwater increases with the decrease of the spacing between double terrains, especially for long-period waves. It is also found that terrain has significant influences on the roll and heave motions, while terrain hardly affects the sway motions. In addition, terrain plays an important role in the mooring forces, while the width and quantity of terrain weakly affect the mooring forces of box-floating breakwater. To investigate the hydrodynamic performance of rectangular floating breakwater in different terrains systematically, Smoothed Particle Hydrodynamics (SPH) methods is used. It can be concluded that the results of SPH show a good agreement with the experimental results.