Dynamic Response Analysis Of Single-point Mooring Wave-powered Floating Platform

Single-point mooring system plays an important role in island construction,marine development,marine agricultural production and other fields.In order to ensure the single-point mooring system has high reliability and good environmental adaptability in different marine environmental loads,as well as the normal operation of the equipment on the platform and the safety of staff,it is very important to accurately simulate the motion characteristics of single mooring system under environmental load.With reference to the DNV offshore floating platform design specifications,this paper studies under the mooring state,the whole coupling system composed of the wave-powered platform-cable-buoy-anchor chain as a integrity to analysis the stability of the platform under the sea environment such as wind,wave and flow.The main researchcontents include the following four aspects:(1)Based on the potential theory,the governing equations and boundary conditions,the mathematical model of " wave-power generation platform-connecting cable-mooring buoy-chain-anchor " is established.The motion of two floating bodies is decomposed,and then the diffraction potential and radiation potential of each floating body are calculated by the velocity potential integral.The overall motion equation of mooring system for floating wave generating platform is obtained.(2)Dynamic analyses were made for mooring anchor chain by geometric nonlinear finite element.Examples shows that this method can correctly derive the motion state of the mooring anchor chain,the mooring force and position of anchor chain are analyzed under different control parameters.Finally,the nonlinear dynamic response of mooring anchor chain is summarized.(3)The coupling analysis for mooring force of anchor chain between the floating wave-powered generation platform and the mooring buoy,under the action of regular wave,is realized by using the hydrodynamic software AQWA.The additional mass force,radiation damping force and six degrees of freedom response of the wave power generation platform with the wave frequency are analyzed.And an analysis of the influence of the wave power generation platform under the change of the incident angle of the environmental load and the pre-tension inclination of the mooring anchor chain ispresented.The simulation results are compared with the experimental data,which shows that the simulation results can reflect the experimental results.(4)Considering the movement of single-point mooring floating wave power generation platform and its mooring cable under the extreme sea conditions of wave,wind and flow.The influence of the spectral peak factor on the power generation platform and the movement of the mooring anchor chain and the platform in the wind,wave,flow collinear and non-collinear are analyzed.