Study On Aeroelastic Response Of Large Floating Offshore Wind Turbine Based On FAST

With the development of wind energy and technology,the design of wind turbines tends to be large-scale and has gradually shifted from onshore wind turbines on land to floating wind turbines on the sea to obtain better wind energy resources.FOWT(Floating Offshore Wind Turbine)is a coupled system with multi degree of freedom,which often bear turbulent wind field,ocean currents and waves in the complicated working environment.Under the action of these coupling effects in these highly allostatic load,floating wind turbine have shown complex motion response,and the motion response will further affect the wind aerodynamic load of the FOWT.On the one hand,the instability of aerodynamic loads will have a great influence on the power of the wind turbine,and on the other hand.As a typical slender structure,the blades of the FOWT are usually designed more than 60m length,the complex and variable aerodynamic loads of wind turbines will put forward higher requirements on the structural strength and aeroelastic performance of blades.Therefore,it is necessary to study the aerodynamic load and the elastic deformation response of the blade of offshore floating wind turbine.In this paper,a large floating wind turbine model is studied with the BEM(Blade Element Momentum)theory and modal superposition method based on the open source code of FAST.The NREL-UAE PhaseVI wind turbine and DTU-10MW wind turbine are used as the simulation models to calculate the aerodynamic load and the elastic deformation response of the blade.Details are as follows:(1)Research was carried out on BEM modified models,which contain tip loss model,dynamic stall model,3D rotation effect modified model and dynamic wake modified model,and the influence and correction effect of each modified model were studied using NREL-UAE PhaseVI wind turbine model test as reference.(2)Based on the open source code of FAST and modified BEM theory,the DTU-10 MW fixed wind turbine was simulated to study the affect of the elastic deformation of blades and tower on the aerodynamic performance of the wind turbine;The aerodynamic loads and elastic deformation responses of the blades in different turbulent wind fields were calculated,and the effects of turbulence intensity on aerodynamic performance and elastic deformation of the blades were summarized.(3)The DTU-10MW semi-submersible floating wind turbine was simulated by using FAST code.Firstly,the hydrodynamic coefficient of the semi-submersible platform is calculated with Sesam.And then the hydrodynamic coefficient calculated by Sesam which are as the input data coupled with the Hydrodyn module to complete the simulation of the whole floating wind turbine.The dynamic response and aerodynamic loads of the FOWT under wind and wave coupling were calculated,and the effects of wind and wave load on the aerodynamic performance were studied respectively.In this paper,the relevant calculation and result analysis of FOWT provide a certain theoretical support and reference for the designs of large-scale FOWT in the future.