Study On Motion Response Of Floating Wind Turbine Foundation With A Wave-energy Floater

In recent years,the increasing exploration and utilization of fossil fuels has resulted in many problems such as resource depletion and environmental pollution.Development of renewable,clean and green energy becomes a mainstream trend to replace the traditional fossil fuels.With rich marine resources and large offshore wind energy density,the comprehensive utilization of wind and wave energy has great potential in the future.To combine the wind and wave energy effectively for achieving optimal resource distribution has become hot point in research now,but not a lot of research on the project has been done.As background to this article,study on motion response of floating wind turbine foundation with a point-absorber type wave-energy converter in both regular and irregular waves is conducted.The following topics are studied in detail.Firstly,mooring system of the floating wind turbine platform is designed.The hydrodynamic parameters of the floating wind turbine platform are calculated using AWQA software based on three dimensional potential flow theories.Two different types of mooring systems with six chains,symmetrical and asymmetrical,are designed for the platform.The motion response of floating wind turbine platform and the chain tension of mooring system are studied in the time domain using OrcaFlex software.According to the results,the asymmetrical mooring system which meets the factor of safety is better than the symmetrical one.Secondly,the numerical model of point-absorber type wave-energy converter is built and verified.Hydrodynamic parameters of the point-absorber type wave-energy converter are calculated using AWQA software in frequency domain.Modeling approach using OrcaFlex software based on a model test campaign which was conducted in the UC Berkeley is given detailedly.The validity and applicability of the numerical model is verified by comparing the results of numerical calculation with the model test results involving the natural periods,motion RAOs and force RAOs.Finally,the motion response of floating wind turbine platform with a point-absorber type wave-energy converter is studied.The mutual response between the platform and the wave-energy converter is studied in regular waves.Besides,the impact of different line stiffness coefficients and different line damping coefficients on the motion response and the normalized capture width of the wave-energy converter is discussed in regular waves.On this basis,the motion response and the normalized capture width of the wave-energy converter is studied in irregular waves considering different wave period,different wave height,different line stiffness coefficients and different line damping coefficients.In conclusion,study on motion response of floating wind turbine platform with a point-absorber type wave-energy converter is carried out in this paper to get the regulation of motion response.Technical support and advices are provided for the comprehensive utilization of wind and wave energy.