Study On The Interaction Of Wave And Circle Floating Bodies Based On The SPH Method

In this paper,a smoothed particle hydrodynamic method(SPH method)based on Lagrangian is used to establish a numerical model to simulate the interaction of waves and buoys.Through the establishment of numerical model,the comparison between the unsteady motion response of the wave and the floating body and the restraining motion response are analyzed,and the SPH method is applied to the establishment and calculation of the numerical net cage,which provides the numerical basis for the floating frame system of the main force components of the cage.The content of this paper is included.Firstly,the basic theory and basic idea of SPH method are introduced,and the construction condition and type of smooth function are introduced.The control equations of SPH method are summarized,including continuity equation,momentum equation,energy equation and state equation.The motion of SPH particle has been introduced.This paper introduces the numerical techniques of SPH method,including boundary,particle action and time integral,and introduces the application of SPH method in rigid body motion and the realization process of SPH program.Secondly,based on the SPH method,three numerical models of fluid motion are established.First,the numerical model of dam break is established to simulate the free flow of water body during the process of dam formation,the water flow,wall collision,and the reflection of the wave comparing with the experimental results.By selecting the pressure monitoring,the pressure changes over time curve is drew.The second is to establish the wedge into the water numerical model.When the wedge is introduced into the water,the surface of the water body is squeezed by the wedge.Under the combined action of various factors such as gravity,pressure and surface tension,the free liquid surface generates pressure with the descending of the wedge,and then draw the curve of its acceleration over time.Third,the numerical model of rigid body motion is established to simulate the impact of water flow on the square floating body and the disturbance of water flow.Thirdly,a numerical wave trough model is established based on the SPH method.Wave propagation is carried out by the wave plate,and the displacement equation of the wave plate is numerically simulated by SPH method.The wave number is established by introducing the first order linear wave,the second order linear wave and the isolated wave.At the same time,two kinds of wave propagation methods,active absorption wave and viscous wave are introduced.Based on the numerical model of viscous elimination wave,three wave height monitoring points has been set.The wave can be verified through the three monitoring points of the wave height.Finally,based on the SPH method,the motion model of the wave and the floating body is established.The response of the buoyant movement of the square,the ring and the cylindrical under the wave action is simulated and analyzed.The velocity,displacement,surge,sway,heave,roll,pitch and yaw are analyzed,and the simulation value of the square floating body is compared with the test value,so as to provide the basis for the numerical calculation of the floating body.