Analysis Of Coupling Effect Of Wave And Structure Based On Smooth Particle Hydrodynamics Method

The effects of waves on structures are common in practical engineering,such as the effects of waves and offshore drilling platform columns,the foundation platform of offshore wind turbines,floating breakwater and offshore floating wave energy generating devices.The structure is subject to the impact and erosion of waves and it is prone to structural fatigue damage and erosion damage,which further affects the stability and reliability of the structure.Based on the above research background,by using the open source program Dual SPHysics,a numerical water tank is established.In this paper,a numerical simulation of the coupling effect of three-cylindrical tube bundle structure,three cylinders with equilateral-triangular arrangement,free-style and moored floating structure is carried out with considering the wave action.The main fingdings are as follows:(1)With the effects of the regular waves and the irregular waves,the influence of different wave incidence angles on its force characteristics is analyzed for the triple-pipe bundle(TPB)structure.The wave period,wave height and water depth are selected as the key parameters to analyze the influence of different parameters on the structural force characteristics.The result shows that the wave force of TPB structure under the action of regular waves is greater than that of irregular wave.As the wave height of the incident wave increases,the statistical value of the wave force on the structure gradually increases.In addition,the flank of the structure is strongly eroded by the wave.The pressure distribution presents a strong three-dimensional characteristic along the spanwise direction of the TPB structure.On the other hand,with the range of Z/D=0.8?1.25,the wave breaking effect is relatively strong and the three-dimensional characteristic of the pressure distribution is further enhanced.(2)With the action of regular waves,the wave force characteristics and wave field of the three cylinders with equilateral-triangular arrangement are considered by different wave direction angles(?=0°?105°)and different wave parameters(wave height and wave period).The influence of the distribution characteristics is compared and analyzed with the cases of the three-cylinder system without a center cylinder,focusing on the analysis of the wave field distribution characteristics of the interaction between the wave and the cylinder,as well as the wave force phase difference distribution characteristics of each cylinder structure.The research results show that the wave statistical value of each cylinder in the three-cylinder system fluctuates significantly as the wave direction angle changes.The statistical value of the wave force of the cylinder shows a decreasing trend with the wave direction angle changing for two cylinders when there is no center cylinder.When the wave direction angle is 30°,the statistical value of the wave force of each cylinder in the three-cylinder system reaches the minimum;the phase difference of the two cylinders in the three-cylinder system is close to 0°,which is in the "in-phase" mode.The center cylinder has a certain influence on the wave field distribution characteristics of the three-cylinder system.(3)With the action of the regular waves,the influence of the force characteristics and the response characteristics of the degrees of freedom of three-dimensional floating bodies with different shape parameters is explored under the action of the waves.The force characteristics and degrees of freedom response of the three-dimensional free-style floating body with different wave incidence angles characteristic are focused on investigating.In addition,the interaction between the waves and three-dimensional moored floating bodies with different shape parameters is calculated,the influence of different wave parameters on the structural force characteristics and the response characteristics of the degrees of freedom are analyzed.The results show that the wave force on the structure gradually increases with the shape parameters of the free floating body increasing under different incidence angles of waves.The longitudinal displacement of the structure is less sensitive to changes in shape parameters.When the shape parameter is A/B=1,the maximum pitch angle of the floating body and its maximum kinetic energy also reach the maximum.Under the action of the waves,the vertical time-average wave force of the moored floating body gradually decreases with the shape parameter A/B increasing,while the time-average wave force in the streamwise direction gradually increases.