三维效应对大型风力机叶片气动-结构特性影响的数值研究

NUMERICAL STUDY ON AERODYNAMIC-STRUCTURE CHARACTERISTICS OF LARGE WIND TURBINE BLADES CONSIDERING THREE-DIMENSIONAL EFFECTS

研究以NREL 5 MW风力机叶片为对象,建立了考虑三维效应的叶片气动-结构数值模型,对比研究了CFD和BEM两种数值模拟方法对复合材料叶片的表面流动、气动载荷特性以及结构变形计算结果的影响。研究结果表明:对于梁帽碳纤维增强的叶片,CFD与BEM气动模型计算得到的载荷集中力大小差异对结构变形的计算结果几乎不产生影响;与传统四分之一弦长气动中心相比,考虑三维效应计算得到的叶片压力中心在距离前缘相对弦长0.30~0.35范围内波动,不同的气动载荷作用位置会对弯扭耦合角位移计算结果产生影响;与传统气动中心相比,以压力中心为载荷作用位置计算得到的角位移曲线峰值点前移,最佳铺层角度减小。因此,建立考虑三维流动效应的叶片气动-结构数值模型,对大型风力机叶片的设计和分析具有重要的指导意义。

The aero-structural numerical model of the blade considering the three-dimensional effect is established for the NREL 5 MW wind turbine blade.Calculation results for the surface flow,aerodynamic load characteristics and structural deformation of the composite blade by two numerical simulation methods of CFD and BEM are comparatively studied.It is demonstrated that for the spar cap carbon fiber reinforced blade,the difference of the load concentration force calculated by the CFD and BEM aerodynamic models has little effect on the calculation results of the structural deformation.Compared with the traditional quarter chord-wise aerodynamic center,the pressure center of the blade considering the three-dimensional effect fluctuates in the range of 0.30-0.35 relative to the chord length from the leading edge,and different aerodynamic loading positions affect the calculation results of bending-torsional coupling angular displacement.Different from the traditional aerodynamic center,the peak point of the angular displacement curve calculated by taking the pressure center as the load action position moves forward,and the optimal laminate layout angle decreases.Therefore,the establishment of a blade aero-structural numerical model considering the three-dimensional flow effect has important guiding significance for the design and analysis of large wind turbine blades.