# Comparative Study on Vibration Characteristics of Biaxial Carbon/Glass Hybrid Wind Turbine Blades
## 4 Numerical Simulation
### Wind Turbine Model Establishment and Laying  
This article uses ANSYS software to model a blade with an airfoil of NACA0012 and a power of 10 kW. The shell extraction entity is shown in Figure 9.  
Establish a grid division model for the sector blade periodic symmetric impeller model. The entire model adopts tetrahedral surface grid division, using global settings, and selecting tetrahedral and triangular grid types for the free surface grid. The number of model nodes obtained is 79,849 and the total number of units is 79,886. The grid quality is evaluated using the unit quality coefficient, which provides a comprehensive quality measurement standard ranging from 0 to 1. The closer the value is to 1 the better the grid quality. After inspection, the average grid quality of the model is 0.82834, which can ensure the normal operation of subsequent solving steps.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Section** & **Chord Length** & **Torsional Angle** & **a** & **b** \\ \hline
0.1R & 0.698 & 22.57 & 0.323831 & 0.350373 \\
0.2R & 0.609 & 10.21 & 0.335469 & 0.106903 \\
0.3R & 0.475 & 3.74 & 0.336935 & 0.049591 \\
0.4R & 0.379 & \(-\)0.04 & 0.337211 & 0.028315 \\
0.5R & 0.312 & \(-\)2.48 & 0.337791 & 0.018288 \\
0.6R & 0.264 & \(-\)4.17 & 0.339174 & 0.012825 \\
0.7R & 0.229 & \(-\)5.43 & 0.342193 & 0.009572 \\
0.8R & 0.202 & \(-\)7.42 & 0.34914 & 0.007571 \\
0.9R & 0.178 & \(-\)7.30 & 0.367484 & 0.0065 \\
1.0R & 0.133 & \(-\)8.39 & 0.432106 & 0.007097 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Section Airfoil Parameters Table.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \multicolumn{3}{c}{**NACA0012 Airfoil, Re = 1.5 \(\times\) 106**} \\ \hline \(\alpha/^{\circ}\) & \(C_{L}\) & \(C_{D}\) & \(C_{L}/C_{D}\) & \(C_{M}\) \\ \hline \(-\)5 & \(-\)0.5404 & 0.00767 & \(-\)70.456 & \(-\)0.0052 \\ \(-\)4 & \(-\)0.4317 & 0.00672 & \(-  
Figure 10: Blade Layer Model.  
\begin{table}
\begin{tabular}{c c c c c c} \hline
**Area (m)** & **0–0.8** & **0.8–1.8** & **1.8–2.8** & **2.8–3.8** & **3.8–4.8** \\ \hline Layers & 8 & 7 & 6 & 5 & 4 \\ \hline \end{tabular}
\end{table}
Table 5: Limination Methods of Composite Material Blades.  
Figure 9: 10 kW Wind Turbine Blade Model.  
Set the fluid velocity inlet section and average static pressure outlet section in CFD, with a fluid inlet velocity of 10 m/s. Set the entire blade and flow field boundary as a fluid solid coupling surface. The minimum length of the dynamic grid is 0.0082, the maximum length is 0.56, and the twist degree does not exceed 0.9. After coupling the Fluent module with the ACP (pre) module and achieving stability, the pressure cloud map of the fluid on the entity is obtained as shown in Figure 12.  
According to the figure, the maximum positive pressure value on the blade surface is 64.4024 Pa, distributed in the middle section of the blade. The maximum negative pressure of the blade is \(-127.789\) Pa, mainly distributed at the root of the blade. Set the hub surface as the constraint surface, rotate the entire blade around the Y-axis at the rated speed of  
Figure 11: Flow Field Domain Grid Division.  
Figure 12: Blade surface pressure distribution diagram.  
160 rad/min, set the entire blade as the fluid-structure interaction surface, set the time step as 0.01 s, and calculate and solve the blade.  
The entire simulation process is shown in Figure 13: