## 4 Results and Discussion
#### 4.1.2 Crosswind Speed  
Figure 10 depicts the change in aerodynamic load coefficients for the train passing through the wind barrier area with a 30% porosity under different crosswind speeds. The speed of the HST is 300 km/h. Tables 3 and 4 present the amplitude of changes in the aerodynamic load coefficients during the process. According to Figure 10 and Tables 3 and 4, it can be observed that the crosswind speed significantly influences the aerodynamic load coefficient of the HST when passing through the wind barrier area. As the crosswind speed increases, the aerodynamic load coefficients also increase. Moreover, the amplitude of the aerody \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Porosity**} & \multirow{2}{*}{**Carriage**} & \multicolumn{5}{c}{\(\Delta\mathcal{C}\)} \\  & & \(C_{D}\) & \(C_{L}\) & \(C_{M}\) & \(C_{D}\) & \(C_{L}\) & \(C_{M}\) \\ \hline \multirow{3}{*}{10\%} & Head & 0.1067 & 0.0399 & 0.0235 & 0.1004 & 0.0430 & 0.0212 \\  & Middle & 0.0299 & 0.0546 & 0.0050 & 0.0277 & 0.0599 & 0.0049 \\  & Tail & 0.0315 & 0.0249 & 0.0066 & 0.0278 & 0.0279 & 0.0060 \\ \hline \multirow{3}{*}{30\%} & Head & 0.0824 & 0.0429 & 0.0117 & 0.0771 & 0.0396 & 0.0116 \\  & Middle & 0.0234 & 0.0566 & 0.0021 & 0.0233 & 0.0515 & 0.0021 \\  & Tail & 0.0211 & 0.0125 & 0.0042 & 0.0191 & 0.0113 & 0.0042 \\ \hline \multirow{3}{*}{50\%} & Head & 0.0552 & 0.0343 & 0.0081 & 0.0514 & 0.0291 & 0.0077 \\  & Middle & 0.0205 & 0.0290 & 0.0015 & 0.0182 & 0.0293 & 0.0014 \\ \cline{1-1}  & Tail & 0.0126 & 0.0095 & 0.0040 & 0.0091 & 0.0030 & 0.0036 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Amplitude of changes in aerodynamic load coefficients for the HST passes through curved wind barriers with different porosities. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Porosity**} & \multirow{2}{*}{**Carriage**} & \multicolumn{5}{c}{\(\Delta\mathcal{C}_{\text{max}}^{\prime}\)} \\  & & \(C_{D}\) & \(C_{L}\) & \(C_{M}\) & \(C_{D}\) & \(C_{L}\) & \(C_{M}\) \\ \hline \multirow{3}{*}{10\%} & Head & 0.8269 & 0.2306 & 0.1369 & 0.6249 & 0.2029 & 0.11 \\  & Middle & 0.1494 & 0.1797 & 0.0201 & 0.1163 & 0.2514 & 0.0177 \\  & Tail & 0.2286 & 0.1046 & 0.0289 & 0.1727 & 0.1003 & 0.0351 \\ \hline \multirow{3}{*}{30\%} & Head & 0.5794 & 0.2220 & 0.0923 & 0.5269 & 0.1837 & 0.0797 \\  & Middle & 0.0829 & 0.1657 & 0.0106 & 0.0791 & 0.1871 & 0.0094 \\  & Tail & 0.1011 & 0.0857 & 0.0171 & 0.1146 & 0.0551 & 0.0183 \\ \hline \multirow{3}{*}{50\%} & Head & 0.3717 & 0.1651 & 0.058 & 0.342 & 0.1317 & 0.0546 \\  & Middle & 0.0654 & 0.1026 & 0.008 & 0.0617 & 0.0946 & 0.0063 \\ \cline{1-1}  & Tail & 0.0540 & 0.0406 & 0.0146 & 0.0489 & 0.0271 & 0.012 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Amplitude of the rate of changes in aerodynamic load coefficients for the HST passes through curved wind barriers with different porosities. namic load coefficient variation becomes more pronounced when entering and exiting the wind barrier area. For example, at a wind speed of 10 m/s, the amplitude of the change in the lateral force coefficient and the amplitude of the rate of change in the lateral force coefficient of the head car are 0.0519 and 0.3611, respectively. However, when the wind speed escalates to 25 m/s, the corresponding indicators are 0.1467 and 0.9594, respectively, increasing by 182.66% and 164.33%. Therefore, it becomes evident that as the crosswind speeds rise, the degree of the sudden change in the aerodynamic load of the HST when entering and exiting the wind barrier area of a bridge is significantly intensified.