Analysis Of Hydrodynamics And Motion Response Of Floating Wind Turbine Semi-submersible Platform

Energy is an indispensable part of social and economic development and plays an significant role in social civilization.Traditional fossil energy is limited and its consumption will cause a series of environmental problems such as the greenhouse effect.As a renewable energy source,wind energy has many advantages such as abundant storage,clean and pollution-free,and wide distribution.It will play an significant role in maintaining the green ecological environment,improving the energy structure,and mitigating the greenhouse effect in the future.our country’s offshore wind resources are particularly rich,suitable for developing offshore wind power generation,offshore floating wind turbines have broad prospects,and its design and performance research is of great significance.Based on the current advanced platform design,according to the three-dimensional potential fluid theory,this paper has carried out the conceptual design of various forms of semi-submersible platforms,using two aerodynamic load equivalent treatment methods and ANSYS AQWA software to measure the water under different sea conditions.The dynamic and motion response characteristics are compared and analyzed,and the main research is as follows:Firstly,the conceptual design of three-pontoon(Deep Cwind),four-pontoon,and two floating cabin semi-submersible platform floating wind turbines are introduced.The simulation models of various wind turbine platforms are established by ANSYS AQWA for hydrodynamic analysis.The first chapter has used the Fer module to do a frequency domain analysis under the same irregular wave and compared the motion response of various floating wind turbine platforms.Secondly,the method of using the equivalent wind coefficient to deal with the wind load of the wind turbine is explained,and the time domain analysis when only the wave load environmental conditions is carried out.The motion response of the three-pontoon type,the four-pocket type and the two floating cabin type semi-submersible platform floating wind turbines are compared.Afterwards,using the environmental conditions of the combined action of wind,wave and current,the equivalent wind coefficient method was used to analyze the time domain of various platform floating wind turbines,and the motion response of various floating semi-submersible platform floating wind turbines were compared analysis.Finally,the equivalent load method is proposed to couple the wind load of the wind turbine,and the fitting toolbox of MATLAB is used to fit the relationship between the horizontal thrust,torque and output power of the NREL 5MW wind turbine with the incident wind speed.Programming with C++ language was used to simulate the wind of two kinds of NPD pulsating wind spectrum,and the output power of the wind turbine was simulated.Then call the AQWA User-Force module,adopt the aerodynamic-hydrodynamic coupling model,and use the equivalent load method to couple the wind load method of the wind turbine.Under the multiple environmental conditions of the combined action of wind and waves,the time domain of various floating wind turbine platforms is carried out.The top tension of the mooring line of its mooring system was analyzed and checked.Finally,the effects of the equivalent wind coefficient method and the equivalent load coupling method on the floating wind turbine semi-submersible platform under the same environmental conditions are compared.