摘 要：叶片偏航和干扰会显著改变大型风力机表面气动力分布模式，进而影响风力机体系的风振响应和稳定性能.以某5 MW大型风力机为研究对象，首先采用大涡模拟（LES）方法进行了最不利叶片位置下考虑6个偏航角（0°、5°、10°、20°、30°和45°）影响的风力机体系流场和气动力模拟，并与规范及国内外实测结果进行对比验证了大涡模拟的有效性.在此基础上，结合有限元方法系统分析了不同偏航角下风力机塔架-叶片耦合模型的动力特性、风振响应和稳定性能.结果表明：不同偏航角下塔架径向位移均值和均方差的最大值均出现在塔架环向0°和180°处，最大塔底弯矩均出现在环向20°处.0°偏航时各叶片顺风向位移响应极值均大于2.7 m，随着偏航角的增大，塔架顶部径向位移、叶片顺風向位移和叶片根部内力的均值及均方差均逐渐减小，而临界风速则呈现先减后增再减小的趋势.综合表明：0°偏航角下风力机体系气动性能和风振响应均最为不利，45°偏航角下风力机体系的稳定性能最为不利.
关键词：风力机；大涡模拟；偏航效应；气动力分布；风振响应；稳定性能
中图分类号：TK83 文献标志码：A
文章编号：1674—2974（2018）07—0061—10
Abstract： The aerodynamic performances of large wind turbine systems are significantly affected by blade yaw and interference， and then the wind-induced response and stability of the wind turbine system are changed. Taking the 5 MW wind turbine as the example，the flow field and aerodynamic forces of the wind turbine systems considering the six yaw angles （0， 5， 10， 20， 30 and 45 degrees） were simulated by large eddy simulation method， and the numerical simulation results were compared with standard curves to verify the validity of the numerical method. On this basis， the dynamic characteristics， wind-induced response and stability of the wind turbine systems under different yaw angles were analyzed by the finite element method. Main conclusions are as follows： The maximum values of the mean value and the mean square deviation of the radial displacement forthe tower under different yaw angles appearat 0 and 180 degrees， the maximum bending moment at the bottom of the tower appears in the circumferential direction of 20 degrees， and the peak value of three blade tip displacement response under 0 degrees yaw is more than 2.7 m. With the increase of the yaw angle， the mean value and mean square deviation of the radial displacement at the top of the tower， the forward displacement of the blade and the internal force of the blade root are gradually reduced， and the critical wind speed decreases first， then increases and decreases again. The results show that the aerodynamic performance and the wind-induced response of large wind turbine systems is the most unfavorable andthe largest under the 0 degree yaw angle， and the stability performance under 45 degrees yaw angle is the most unfavorable.
Key words： wind turbines；large eddy simulation；yaw effect； aerodynamic force distribution；wind-induced response；stability
由于风向连续变化且风力机偏航系统转速较慢，风力机的叶轮转轴无法及时对准来流风向，导致风力机在日常运营时常处于偏航状态[1-2].由于不同偏航角下处于最不利位置[3]的叶片对塔架的遮挡程度不同，风力机体系的表面流场和气动力分布发生明显变化，进而使得风力机体系的风振响应和稳定性发生改变.因此，对不同偏航角下大型风力机体系的风振响应和稳定性进行系统研究具有重要的工程和理论价值.