Research On Dynamic Response Of Floating Wind Turbine Blade Based On Moving Boundary

The development and utilization of wind energy has become a new trend in energy development,and the wind power industry has developed rapidly,and its scale is also expanding.However,during the operation of the wind turbine,the blade,which is a key part of energy conversion,will be deformed by various loads,causing many problems such as blade cracking and failure.Therefore,it is extremely necessary to carry out research on the strain/stress and displacement of floating wind turbine blades.Based on the dynamic boundary,this paper uses NREL’s 5MW floating wind turbine as a prototype to study the dynamic response of the blades.The main work carried out is as follows:(1)Using FAST software to simulate the movement of the 5MW floating wind turbine under various working conditions,the time history curves of the blade tip displacement,shear force,platform pitch(heave)and other parameters were obtained.After analyzing these curves,it is found that the wind speed is the main factor affecting the dynamic response of the blade,the influence caused by the change of wave period and wave height is small.(2)According to similar criterion,the scale ratio of the test model was determined to be 1:30,and the Solidworks digital model of the 5MW floating fan blade was established.And using Nastran software to carry out finite element analysis on small-scale blades,the distribution law of blade stress along the span direction and the blade stress and displacement under various wind speeds are obtained.The results show that the blade with larger stress area mainly appears in the middle of the blade,and the maximum displacement occurs at the blade tip,and the stress and displacement both increase with the increase of wind speed.(3)Created a 3D blade model based on the scale ratio,and the other components of the floating wind turbine(tower,hydraulic cradle,hub,etc.)are processed in the same proportion.Then the dynamic response model test of floating wind turbine blade based on dynamic boundary was carried out to obtain the strain distribution law of multiple blade positions under different working conditions.(4)The stress data obtained from the numerical analysis was converted into strain,and compared with the test results,it was found that the strain in the middle of the blade was larger,and the strain increased with the increase of wind speed.