Study Of Hydrodynamic Characteristics For Horizontal Plate Breakwater Based On Smoothed Particle Hydrodynamics

The submerged horizontal plate is an open-type breakwater structure.Compared with traditional breakwater structures,it has many advantages:(1)Convenient to be constructed because of its simple shape;(2)No damage to the ocean environment because of its permitting water exchange from inside and out of the breakwater;(3)Be able to satisfy the requirements of wave dissipation performance with different tidal range.Up to now,studies on the hydrodynamic characteristics of horizontal plate breakwater has been widely carried out and some excellent findings have been found.However,it is necessary to conduct further investigation on practical engineering application of the horizontal plate breakwater.In this work,a Smoothed Particle Hydrodynamics(SPH)model is established,and a new method of thin plate structure treatment,the multilayer dynamic boundary particle method,is proposed.The SPH model verified by experiments is used to study the hydrodynamics of the horizontal plate breakwater interaction with waves,and the functionality of wave energy utilization of the horizontal plate breakwater is further studied.On the basis of the SPH model,a coupled SPH-FEM model is established to analyze the interaction between waves and elastic submerged horizontal plate.The main research results are as follows:(1)In the sea area with moderate tidal range,a single-plate breakwater is insufficient to the wave dissipation.The twin-plate breakwater system formed by setting a horizontal plate under the high and low tidal levels respectively,can meet the requirements of the tidal level fluctuation,and it is suggested that the vertical spacing of the twin-plates breakwater should be set as the height of tidal range.(2)SPH-FEM coupling model is used to calculate the hydrodynamics of elastic plates with different bending stiffness.The results show that the 1th-order transmission coefficient of horizontal plate breakwater is positively corr elated with the plate stiffness,while the 2th-order transmission coefficient is opposite.The maximum upward wave force is positively related to the plate stiffness,while the maximum downward wave force is opposite.(3)Apart from being a breakwater,the submerged horizontal plate can also be regarded as a wave energy convertor(WEC).When the horizontal scale of the plate is relatively larger and its immersion depth is shallower,the submerged horizontal plate can dissipate more incident waves.On the contrary,When the horizontal scale of the plate is relatively shorter and its immersion depth is deeper,the submerged horizontal plate can convert more wave energy.The conclusions drawn in this work provide theoretical support for engineering application of horizontal plate breakwater.