Dynamic Response Analysis Of Floating Offshore Wind Turbine In Combined Wind And Wave

In recent years,the reserves of traditional energy represented by fossil energy are declining rapidly,and it has been increasingly difficult to meet the needs of the economic development and the progress of civilization in human society.At the same time,the pollution of these traditional energy to the environment is aggravating and directly endangering human health.In order to solve this energy dilemma,people are devoted to the development and utilization of renewable energy,especially for the clean,pollution-free and widely distributed wind energy.Wind power firstly has been developed rapidly on land.However,due to the geographical and scale restrictions of wind turbines on the land and the damage to the surrounding ecology caused by wind farms,the transfer of wind farms from land to sea has become a new trend.With the expansion of wind power development,offshore wind turbines(OWTs)also have a tendency to develop from offshore,fixedbottom OWTs to deep-sea and floating OWTs.Floating offshore wind turbines(FOWTs)are the targets of this paper.FOWT will encounter variety of harsh sea condition composed of wind and wave,in order to ensure safety and reliability,it is necessary to analyze and study the dynamic response of FOWTs under different sea conditions,and this is exactly the subject of this paper.In this paper,the time-domain motion equation is obtained by indirect time-domain method which is based on the three-dimensional frequencydomain potential flow theory and the impulse response function method.What's more,the mooring force is considered,and the quasi-static cable model is used to solve the mooring force;wind forces is also consider,and the forces is obtained by blade element momentum method,and the viscous effect is considered,too,viscous damping coefficient is used to account for the viscous effect,while the viscous damping coefficient is calculated by computational fluid dynamics.Finally,the time-domain equation of FOWTs in combined wind and wave is obtained.The dynamic response of the FOWTs in combined effect of wind and wave can be obtained by solving this equation.In this paper,the dynamic response of FOWTs under five conditions of steady wind,dynamic wind,regular waves,irregular waves and combined wind and wave are analyzed.The results are compared with the experimental results and numerical simulation results of other institutions.It is shown that the method of potential flow theory and viscous flow theory used in this paper is suitable for the dynamic response simulation of FOWTs.