Dynamic Characteristics Analysis Of Multi-field Coupling Single Point Mooring System

With the continuous development of marine technology,the scope of development using renewable energy to generate electricity is gradually expanding.In the harsh marine environment,the wave power generation device will undergo various changes with the change of the environment,which will have different degrees of impact on the efficiency of power generation.Therefore,it is possible to accurately simulate the harsh conditions of the mooring system in the power generation device.Various movements in the environment are particularly important for wave power generation.Based on the single-point mooring system as the research object,based on the potential flow theory,terminal condition and control equation of the catenary mooring system in the wind,wave and flow mathematical model is set up under the function of environmental load.Research under the condition of the different environmental parameters,floating body movement characteristics of the six directions and the size of tension of mooring line.In addition,the motion characteristics of the two mooring methods caused by environmental loads in different directions are studied.Firstly,the related types of wind,wave and current environmental loads suffered by wave power generation devices on the ocean and the empirical theoretical calculation formulas are introduced.Because of the complexity of wave load,many researches and calculations have been carried out.Then,based on the three-dimensional potential flow theory,boundary conditions and governing equations,the kinematics equations of the mooring system under the multi-field coupling environment are established.Secondly,this paper introduces the mooring system: catenary mooring and mooring tension type,at the same time the mooring line material for mooring system and a variety of mooring distribution and classified.And by different methods in detail to calculate the catenary equation under different conditions.Then,using ANSYS software's hydrodynamic simulation module AQWA to model and simulate the mooring system,the radiant damping force,additional mass force,and wave cycle change of the floating body's six degrees of freedom with the wave frequency change are obtained.The amplitude response operator(RAO).Subsequently,on the one hand,the motion response of different water flow shape models to the mooring system and the tension change of the mooring line under the multi-field coupling environment were studied,and the comparison and analysis were carried out.On the other hand,the movement characteristics of the mooring system under normal wind and extreme sea breeze are discussed.Finally,it discusses the changes in the motion response of the mooring system and the tension of the mooring line in the two different mooring methods under the action of wind,waves,currents and other environmental loads in the same direction under various conditions,and then compares and analyzes them.