Transient Aeroelastic Interaction FSI Simulation And Aerodynamic Performance Analysis Of Large Offshore Wind Turbine

With the rapid development of the world economy,the development and utilization of energy are becoming more and more important.The development and utilization of renewable energy will become the object of vigorous development of all countries in the future.Wind energy,as a clean and renewable energy source,has developed rapidly in recent years due to its mature technology and large storage capacity.Wind turbine usually works in an open environment in the field.The constantly changing load and the flexible structure will have a coupling effect,and the blades will be deformed and twisted.When the deformation is too large,the vibration is too large or the stability is unstable,the blades will suffer from fatigue damage.Therefore,it is of practical significance to study the aerodynamic performance,deformation stress and mode of wind turbine under the condition of rated wind speed by means of fluid-solid coupling.In this paper,NREL 5MW wind turbine is taken as the research object.The aerodynamic performance of wind turbine under different grids and different wind speeds is calculated respectively,and compared with the design value in the literature,so as to verify the correctness of wind turbine modeling and flow field model.Under the rated wind speed of wind turbine two-way fluid-structure coupling calculation,the results show that blade can produce large deformation,blade maximum deformation of about 1 m,the maximum deformation occurs at the tip.The maximum deformation of three blades is different,the maximum deformation difference of the blades is about 0.15m The largest deformation stress larger central area mainly focused on the windward side.After coupling,the axial thrust and output power of the wind turbine are increased.In order to study the aerodynamic characteristics of wind turbine blades,a concrete method is proposed to integrate the velocity circulation value around the two-dimensional airfoil.Taking NACA64 A17 airfoil as an example,this paper shows how to find the optimal integral path to calculate the circulation.Through the analysis of the circulation of two-dimensional airfoil,the influence of integrated path and airfoil angle of attack on the integral value is studied.The integration results are compared with the classical kuta-zhukowski theorem,and then the research results are applied to the three-dimensional calculation of the circulation distribution of wind turbine blades.Velocity circulation distribution of blades with different inlet flow speeds is analyzed,and the influence of the circulstion distribution of blades on the aerodynamic characteristics of blades is compared.