SPH Modeling Of Wave Interaction With Floating Breakwater

Compared with traditional bottom mounted breakwaters Floating Breakwaters(FBs)have many advantages.They can be equally effectively used in offshore or coastal areas with poor foundation.They generally also have relatively less environmental impact and involve short duration of installation and potentially lower construction cost.This has led to the development and application of various types of FBs during the last decades.Therefore,increasing attention has been recently received on the interaction between waves and a moored floating breakwater.In order to overcome the problems associated with grid-based methods,the Smoothed Particle Hydrodynamics(SPH)method is used to model the interaction between waves and a moored floating breakwater.The application of a Smoothed Particle Hydrodynamics(SPH)model to simulate the nonlinear interaction between waves and a moored floating breakwater is presented.A 2D numerical wave tank(NWT)based on SPH method is developed.An active absorbing wave maker is set at the upstream boundary of the NWT to generate a propagating wave,and a damping layer is used to absorb the waves at the downstream boundary of the NWT.The Euler equations together with an artificial viscosity are used as the governing equations to describe the flow field.Boundaries of the NWT and the floating structure are treated by the dynamic boundary particles(DBPs)proposed by Dalrymple.The calculated densities of the dynamic boundary particles are corrected by weight averaging of the densities of the neighboring fluid particles.The motion of the moored floating body is described using the Newton's second law of motion.The floating body is taken as a rigid body and a light spring model is employed to calculate the mooring force.The water surface elevations near the floating structure are recorded using four wave gauges.The artificial viscosity parameter is obtained by a series of tests.The water surface elevations,the movements of the floating body and the moored forces are all calculated and compared with the available experimental data.Good agreements are obtained for the dynamic response and hydrodynamic performance of the floating body.The application of a Smoothed Particle Hydrodynamics(SPH)model to simulate the nonlinear interaction between waves and a moored floating breakwater is presented.The main aim is to predict and validate the response of the moored floating structure under the action of periodic waves.The numerical results of different immersed depths of the floating body are presented and the effects of the relative length and the density of the structure on the performance of the floating body are analyzed.A series of numerical experiment results show that the SPH model is accurate for wave breaking and overtopping on the top of the floating body.The reflected wave heights and transmitted wave heights are shown to discuss the wave attenuation effect of the floating body.The velocity fields and pressure fields for different floating structure are displayed to analyse the hydrodynamic performance of the floating body.In conclusion,the numerical model presented in this paper can be used as a powerful tool to study the interactions of waves with floating structure.