基于时间推进自由尾迹法的水平轴风力机气动特性分析

Computation on Aerodynamic Performance of Horizontal Axis Wind Turbine Based on Time-marching Free Vortex Method

建立适合于水平轴风力机气动特性分析的自由尾迹计算方法。该方法中,桨叶模型采用Weissinger-L升力面模型,转子自由尾迹的求解采用时间推进方法,数值求解方法采用4阶Adams-Moulton预估–校正算法以提高计算精度。应用所建立的方法对模型风力机处于轴向来流工况时的尾迹形状和气动特性进行计算,并与文献实验数据进行比较,验证了该方法的有效性。最后计算了来流风偏转和桨叶桨距角增加时尾迹形状的非定常畸变及气动载荷特性,得出一些有意义的结论。

A computational method based on rotor free-wake model was developed for horizontal axis wind turbine＇s aerodynamic performance prediction. The analytical method combined a Weissinger-L lifting surface model with a time-marching free vortex method to simulate the rotor flow field. Adams-Moulton predictor-corrector scheme was used to improve computational order of accuracy. The comparison between the calculated results of model wind turbine under axis flow condition, including tip vortex geometry and aerodynamic performance, and available experimental data shows that this method is suitable for wind turbine aerodynamic performance analysis. Finally, a series of numerical calculations were made to investigate the evolving of tip vortex geometry and aerodynamic performance of the wind turbine when yawing 30° out of the wind and pitch angle increasing from 2° to 4°, some significant conclusions were obtained.