基于涡旋升力线模型的风机后掠叶片性能优化

Performance optimization of back-swept blades for wind turbines based on vortex lift line model

为精确模拟后掠叶片的气弹特性,基于升力线理论建立后掠叶片非线性气弹耦合模型,并通过计算国家可再生能源实验室(NREL)5 MW直叶片和后掠叶片的稳态响应,验证模型的有效性和准确性.以运行变桨角为设计变量,年发电量为目标函数,以额定功率、叶尖挥舞位移和轴向推力作为约束条件,选择5 MW后掠叶片为原型,寻找5~25 m/s风速范围内各风速对应的最优变桨角,并将结果进行对比分析.结果显示,变桨角优化的后掠叶片,相比于原型叶片以及直叶片,年发电量分别提高8.58%、7.59%.

In order to accurately simulate the aero elastic characteristics of back-swept blades,a nonlinear aero elastic coupling model of back-swept blades based on lift line theory was established.Through calculating the steady-state response of 5 MW straight blades and back-swept blades in the national renewable energy laboratory(NREL),the validity and accuracy of models were verified.Taking the operating pitch angle as design variable,the annual energy production as objective function,the rated power,the flap wise tip deflection and the axial thrust as constraint criterions,the 5 MW back-swept blades were chosen as prototypes,the optimal pitch angles at each wind speed ranging from 5 m/s to 25 m/s were determined,the results were compared and analyzed consequently.The results show that the annual energy production of back-swept blades with the optimized pitch angles increases by 8.58%and 7.59%,respectively,compared with the prototype and straight blades.