偏航对风力机气动性能影响的数值模拟研究

摘要

采用基于滑移网格模型的三维非定常数值模拟方法,对NREL Phase VI风力机在轴流工况下的气动性能进行计算,并与参考文献提供的实验值进行比较,验证了方法的可靠性.然后对该风力机在偏航工况下的尾迹结构和气动性能进行计算,结果表明:偏航工况时,风力机尾迹呈现明显的偏斜特性,且尾迹区的速度恢复比轴流工况慢;旋转周期内,叶片根部和中部受偏航入流的影响较大,导致叶片表面压力变化较大且吸力面流动分离严重,而叶尖区域受偏航的影响较小.计算结果能够为研究风力机的动态失速以及风场中风机群的优化布置等问题提供指导.%The aerodynamic characteristics of NREL Phase VI wind turbine under axial inflow are computed based on sliding meshing of 3D unsteady CFD method. The comparison between calculated results and available experimental data shows that the method is suitable for wind turbine analysis. The wake structure and aerodynamic characteristics of NREL Phase VI under yawed inflow condition are computed. Results show that: the wake of rotor presents deflection under yawed inflow, and the recovery of wake velocity is slower than axial inflow; the flow at inboard blade sections is affected by yawed inflow greatly, which result in change of pressure and separate of flow at suction side more severe than outboard regions. The conclusions can provide guidance for research of dynamic stall and optimal arrangement of wind turbine.