Optimal design of wind turbine airfoils based on functional integral and curvature smooth continuous theory

The current airfoil design methods are based on one point of design angle of attack, in order to seek the local maximum aerodynamic performance without considering the whole aerodynamic performance within continuous design angle of attack. Based on airfoil functional integral and complicated profile curvature smooth continuity theory, a novel airfoil design method considering continuous angle of attack is presented. It not only can make the aerodynamic force convergence, but also has the whole aerodynamic performance increased. A parametric optimal mathematical model of wind turbine airfoil profiles is established to maximum the overall high aerodynamic performance. The aerodynamic comparison of the WQ-B airfoil series which are designed considering continuous angle of attack and the WQ-A airfoil series which are designed without considering continuous angle of attack is analyzed. Meanwhile, the comparison of WQ-B210 airfoil and DU96-W-210 airfoil is studied. Compared with WQ-A210 airfoil and DU96-W-210 airfoil, the WQ-B airfoil series exhibit high aerodynamic performance, especially for the average lift coefficient and lift–drag ratio. At last, the WQ-B airfoil series are used to a real 2MW wind turbine blade. The results are shown that, compared with the actual blade, the new wind turbine blade exhibit better whole performance. This study verifies the feasibility for the novel design method. Moreover, it also indicates that the WQ-B airfoil series have broad generality and substitutability.