摘要
以某33 kW两叶片水平轴风力机的风轮为研究对象,采用CFD方法,研究风剪切来流下水平轴风力机流场特性与风轮气动载荷的分布规律。结果表明:在剪切来流下,风轮上游来流风速随方位角的波动曲线偏离由理论计算得到的风速波动曲线;尾流区轴向速度呈现非对称性分布,轮毂上方叶尖涡和叶根涡的移动速度大于轮毂下方叶尖涡和叶根涡的移动速度;同时,风力机叶片和风轮的气动载荷随方位角呈现正余弦的变化趋势,风轮气动载荷功率谱曲线的峰值对应的频率与叶片通过频率的整数倍相关。当风剪切指数由0.1增大到0.5时,风轮转矩和推力的均方根分别减小2.28%和1.43%,但其波动幅值随风剪切指数的增大而增大,并且风轮转矩和推力随方位角的波动曲线存在相位偏移现象,风剪切指数越大,相位偏移现象越明显;风轮偏航力矩和倾覆力矩的均方根分别增大4.07倍和4.04倍,且其波动幅值随风剪切指数的增大而增大。
A rotor of 33 kW two-blade horizontal axis wind turbine is simulated under the shear inflow conditions. The flow field characteristics and the aerodynamic loads of the horizontal axis wind turbine are studied by CFD method. The results show that the fluctuation curves of velocity with azimuth angle at the upstream of rotor deviate from the curves obtained from the theoretical calculation in shear inflow,and the axial velocity of wake region presenting asymmetry distribution. The moving speed of the tip vortex and root vortex above the hub is faster than that of below the hub.Meanwhile,the aerodynamic loads of wind turbine blade and rotor vary with azimuth angle in a sine or cosine way and the frequency corresponding to the peak of the power spectrum of the rotor load are related to the integral multiples of the blade passing frequency. When the wind shear exponent increases from 0.1 to 0.5,the average torque and axial force of rotor decrease 2.28% and 1.43% respectively,but the fluctuation amplitude increases gradually. Moreover,a phase shifting of the torque and axial force as functions of azimuth angle is found,and the larger the wind shear exponent,the more obvious of the phase shifting. The root mean square of yaw moment and tilt moment of rotor is increased by 4.07 times and 4.04 times respectively,and the fluctuation amplitude of rotor yaw moment and tilt moment increases gradually with the increase of wind shear exponent.
作者
张旭耀
杨从新
李寿图
郜志腾
罗颂
Zhang Xuyao;Yang Congxin;Li Shoutu;Gao Zhiteng;Luo Song(School of Energy and Power Engineering,Lanzhou University of Technology,Lanzhou 730050,China;Key Laboratory of Fluid Machinery and Systems,Lanzhou 730050,China)
出处
《太阳能学报》
EI
CAS
CSCD
北大核心
2019年第11期3281-3288,共8页
Acta Energiae Solaris Sinica
基金
国家重点基础研究发展（973）计划（2014CB046201）
国家自然科学基金（51566011)
关键词
风剪切
风力机
流场特性
气动载荷
wind shear
wind turbine
flow field characteristics
aerodynamic loads
