Research on Start-up Performance of the Vertical Axis Wind Turbines with Symmetrical and Asymmetrical Airfoils at Low Wind Speeds

In this paper, the start-up performance of vertical axis wind turbines (VAWTs) with symmetric and asymmetric airfoils in low wind speed environments was investigated by numerical simulation methods. Simultaneously, two kinds of VAWTs were compared and analyzed in terms of their self-starting capabilities within a context of low wind speeds. The airfoils NACA0021 were chosen as the symmetric airfoils, and the asymmetric airfoils chosen airfoils DU97-W-300. The research compared the static starting moment coefficients of the two airfoils at various azimuths. Furthermore, the effects of various blade numbers and blade rotation radii on the start-up performance of symmetric and asymmetric airfoil wind turbines were also compared. Three low wind speed environments (v=4m/s, 5m/s, 6m/s) were chosen for this exploration. The research demonstrates that the wind turbines with airfoils DU97-W-300 had more effective self-starting properties in low wind speed environments than the wind turbines with airfoils NACA0021.