考虑叶片桨距角和干扰效应的大型风力机体系风致效应研究

STUDY ON WIND-INDUCED EFFECTS OF LARGE WIND TURBINE SYSTEM CONSIDERING BLADE PITCH ANGLE AND INTERFERENCE EFFECT

以某5 MW大型风力机为对象,首先基于大涡模拟(LES)技术进行考虑不同叶片桨距角影响的大型风力机体系非定常流场和气动力模拟,并与规范及实测结果进行对比,验证大涡模拟的有效性。在此基础上,结合有限元方法系统分析不同叶片桨距角下风力机塔架-叶片耦合体系的动力特性、风振响应、屈曲稳定性能和极限承载能力。研究表明:0°叶片桨距角下塔架显著干扰区段迎风面0°处出现负压,叶片顺风向位移响应极值最大值为3.98 m。随着叶片桨距角的增大,塔顶径向位移、各叶片顺风向位移和叶根剪力的均值和均方差均呈逐渐减小的趋势,且叶片桨距角在30°~50°范围内出现显著变化。叶片桨距角为0°时风力机体系风致响应最为不利,当叶片桨距角为90°时,体系屈曲性能和极限承载力最为不利。

5 MW large wind turbine taken as the study object,large eddy simulation method is used to simulate the unsteady flow field and aerodynamic force of large-scale wind turbine system considering different blade pitch angles(0°,10°,20°,30°,40°,50°,60°,70°,80°and 90°).The simulation results are compared with the standard and measured results to validate effectiveness of large eddy simulation.On this basis,Dynamic characteristics,wind-induced vibration response and stability of wind turbine tower-blade coupling system under different blade pitch angles are systematically analyzed combining finite element method.The main conclusions are as follows:when the blade pitch angle is 0°,negative pressure appears at 0°windward side on the significant interference zone of the tower,the maximum extreme value windward displacement of blade is 3.98 m.With the increase of blade pitch angle,the mean value and mean square error of radial displacement of tower top,blade windward displacement and shear of each blade root all show a decreasing trend,and significantly change in the range of pitch angle of 30°-50°.Under the condition of 0°blade pitch angle,windinduced response of wind turbine system is the most disadvantageous.With 90°pitch angle,buckling behavior and ultimate bearing capacity of the system are the most disadvantageous.