## 1 Introduction
The results showed that irregularly shaped ice structures greatly disturbed airflow around the blades, leading to the shedding of unstable vortex structures from the surface of the accumulated ice and causing significant degradation in aerodynamic performance [20]. [PERSON] and [PERSON] et al. simulated the aerodynamic and structural performance of a wind turbine on an iced-up NACA 4412 airfoil and a NACA 64-618 airfoil. The results showed that when ice accumulates on the surface of a blade, the shape of its profile is changed, the lift and drag coefficients change significantly, and the aerodynamic and structural performance of the wind turbine is degraded [21; 22]. [PERSON] et al. investigated the aerodynamic characteristics of S832 and S826 airfoils with icing profiles based on CFD numerical analysis, and the CFD analysis showed that the airflow behavior of iced blades changed compared with that of un-iced blades, which led to the degradation of aerodynamic performance, and that the change in the aerodynamic characteristics of S832 was more obvious than in S826 [23]. [PERSON] and [PERSON] et al. simulated different icing shapes and aerodynamic characteristics of icing airfoils. The results showed that the aerodynamic characteristics of the icing airfoils were degraded by a decrease in the lift coefficient and an increase in drag compared to un-iced shapes [24; 25]. [PERSON] et al. suggested an improved icing calculation model based on different time scales to reveal the effects of yaw icing on aerodynamic characteristics. The results showed that aerodynamic properties, such as the lift and drag coefficients of localized airfoils, are further reduced under yaw icing conditions, leading to a reduction in wind turbine power, thrust, and blade root moment; the results are summarized in the following table [26]. [PERSON] et al. investigated the effects of glaze ice and freezing ice conditions on wind turbine aerodynamics through numerical simulations. It was found that more ice is formed at lower temperatures in freezing ice conditions, and the wind turbine performance was reduced by a maximum of 40% [27]. [PERSON] et al. investigated the static performance of a wind turbine at different uniform wind speeds between cut-in and cut-out wind speeds by simulating and analyzing a 5 MW wind turbine blade with light icing. The results showed that mild icing changed the aerodynamic and dynamic characteristics of the wind turbine by increasing the cut-in and rated wind speeds and decreasing the thrust and maximum power coefficient by 5.5% and 13.35%, respectively [28]. [PERSON] et al. investigated the effect of icing on the performance of a pitch-regulated large wind turbine by performing numerical simulations of six blade sections of an NREL 5 MW wind turbine at different free-stream speeds. The results showedthat the blade tips were most affected by icing and the maximum degradation of wind turbine performance was about 24% [29]. Till now, most studies have focused on the blade icing requirement or ice shape change and ice accumulation distribution under different icing conditions. There are few quantitative studies on the change of airfoil shape under different icing conditions along the chord length direction and blade spanwise direction. By quantitatively analyzing the changes in airfoil data from quantitative studies, the changes in aerodynamic characteristics of wind turbine icing blades were refined. The 600 W wind turbine blade under nonicing and different icing conditions was scanned by using a 3D scanner. The thickness and shape of icing on the blade surface were measured and calculated. A database of the ice shape of the wind turbine blade and its icing airfoil was established, and the icing state parameters of the wind turbine blade and its airfoil as a whole under different icing conditions were investigated.