针对高湿、寒冷地区覆冰造成机组出力减少的问题,以 NREL S809二维翼型及某型300kW风力机三维风轮为研究对象,采用计算流体力学(CFD)数值仿真方法,结合覆冰粗糙度模型,研究分析覆冰粗糙度对风力机叶片气动性能的影响规律.计算结果表明:对于改变翼型气动外形较小的覆冰,二维翼型的气动性能随着覆冰粗糙度大小、覆冰相对宽度的增加而降低,随着攻角的增加影响变大;对于改变翼型气动外形较大的覆冰(雾凇或雨凇),雨凇覆冰的破坏作用更大,但雾凇覆冰翼型受覆冰粗糙度影响更大;叶片覆冰导致三维风轮气动性能降低,在大风速下更为显著;随着覆冰粗糙度大小的增加,三维风轮输出转矩和轴向推力降低,且随着风速的增加,降低程度变大.该文的计算结果对覆冰地区风电场运行及机组性能评估有一定的参考价值和借鉴意义.%Wind turbines in humid and cold regions often suffer blades icing problems resulting in the loss of power generation. In the paper, the CFD methods combining with ice equivalent roughness model are carried out on NREL S809 airfoils and a 300kW wind turbine rotor to investigate the influence of ice roughness on aerodynamic performance of wind turbine blades. The conclusions are as follows. For slight ice not to change the airfoil shape, the 2D profile aerodynamic performance decreases with the increase of ice surface width and ice roughness height, especially more remarkably in higher AOAs (angle of attack). For rime or glaze ice, glaze ice causes greater damage, however, the rime-iced profile is influenced by ice roughness more significantly. In terms of 3D rotor with iced blades, the aerodynamic performance declines more dramatically at higher wind speed. In addition, both the output torque and axial thrust of the rotor decrease with the increase of ice roughness, and the downtrends are becoming more apparent with the increase of the wind speed. The results will provide a valuable reference for both wind farm operation and generator system evaluation in icing districts.
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