## 4 Characteristics of Outdoor Wind Field at National Sliding Centre
### Comparative Analysis of Outdoor Wind Field Characteristics  
Based on the above analysis of the wind field distribution characteristics of the NSC, we established a line graph showing the variation in the global wind speed dispersion \(\overline{\text{L}}_{\text{a}}^{\text{b}}\) with the area and wind direction, as shown in Figures 9 and 10. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multicolumn{2}{c}{**Area**} & \multicolumn{1}{c}{**Area I**} & \multicolumn{1}{c}{**Area II**} & \multicolumn{1}{c}{**Area III**} & \multicolumn{1}{c}{**Area IV**} \\ \hline \multirow{4}{*}{**Windward region**} & **Wind speed** & 1.58–3.56 m/s & 2.28–3.65 m/s & 1.99–3.63 m/s & 0.32–4.74 m/s \\ \cline{2-6}  & **Wind pressure** & 0.79–6.19 Pa & 0.21–5.05 Pa & 0.23–5.79 Pa & \(-\)13.30–5.80 Pa \\ \cline{2-6}  & **Average wind pressure** & 1.73 Pa & 0.49 Pa & 0.60 Pa & 0.13 Pa \\ \hline \multirow{4}{*}{**Venue region**} & **Wind speed** & 0.0020–5.94 m/s & 0.0011–8.38 m/s & 0.0021–7.33 m/s & 0.0011–6.82 m/s \\ \cline{2-6}  & **Maximum wind speed** & 5.94 m/s & 8.38 m/s & 7.33 m/s & 6.82 m/s \\ \cline{2-6}  & **Global wind speed** & \(\overline{\text{L}}_{1}^{3}=1.8248\) & \(\overline{\text{L}}_{2}^{3}=0.2498\) & \(\overline{\text{L}}_{3}^{3}=1.6657\) & \(\overline{\text{L}}_{4}^{3}=0.1749\) \\ \hline \multirow{4}{*}{**Leeward region**} & **Wind pressure** & \(-\)4.28–\(-\)\(-\)0.58 Pa & \(-\)2.69–0.56 Pa & \(-\)2.53–0.26 Pa & \(-\)3.39–0.64 Pa \\ \cline{2-6}  & **Average wind pressure** & \(-\)2.16 Pa & \(-\)0.15 Pa & \(-\)0.31 Pa & 0.04 Pa \\ \hline \multicolumn{2}{c}{**Pressure difference between windward region and leeward region**} & 10.47 Pa & 7.74 Pa & 8.32 Pa & 9.19 Pa \\ \hline \hline \end{tabular}
\end{table} 
Table 4: The wind field distribution characteristics when the wind direction is NWN. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multicolumn{2}{c}{**Area**} & \multicolumn{1}{c}{**Area I**} & \multicolumn{1}{c}{**Area II**} & \multicolumn{1}{c}{**Area III**} & \multicolumn{1}{c}{**Area IV**} \\ \hline \multirow{4}{*}{**Windward region**} & **Wind speed** & 1.62–3.52 m/s & 2.25–3.64 m/s & 1.94–3.63 m/s & 2.09–4.07 m/s \\ \cline{2-6}  & **Wind pressure** & 1.06–7.07 Pa & 0.01–5.06 Pa & 0.21–5.98 Pa & \(-\)1.91–5.50 Pa \\ \cline{2-6}  & **Average wind pressure** & 2.21 Pa & 0.56 Pa & 0.58 Pa & 0.25 Pa \\ \hline \multirow{4}{*}{**Venue region**} & **Wind speed** & 0.0007–6.56 m/s & 0.0029–7.57 m/s & 0.0012–6.04 m/s & 0.0018–8.90 m/s \\ \cline{2-6}  & **Maximum wind speed** & 6.56 m/s & 7.57 m/s & 6.04 m/s & 8.90 m/s \\ \cline{2-6}  & **Global wind speed** & \(\overline{\text{L}}_{1}^{2}=2.0187\) & \(\overline{\text{L}}_{2}^{2}=0.2879\) & \(\overline{\text{L}}_{3}^{2}=1.6350\) & \(\overline{\text{L}}_{4}^{2}=0.2590\) \\ \hline \multirow{4}{*}{**Leeward region**} & **Wind pressure** & \(-\)7.99—\(-\)0.54 Pa & \(-\)4.34–0.77 Pa & \(-\)2.02–0.41 Pa & \(-\)5.74–0.64 Pa \\ \cline{2-6}  & **Average wind pressure** & \(-\)2.33 Pa & \(-\)0.25 Pa & \(-\)0.10 Pa & 0.00 Pa \\ \hline \multicolumn{2}{c}{**Pressure difference between windward region and leeward region**} & 15.06 Pa & 9.39 Pa & 7.99 Pa & 11.25 Pa \\ \hline \hline \end{tabular}
\end{table} 
Table 3: The wind field distribution characteristics when the wind direction is NW. As can be seen from Figures 9 and 10, the global wind speed dispersion in Area I is generally larger than that in other areas. When the wind direction is NWN, the global wind speed dispersion is the smallest, and the wind speed distribution is relatively uniform. The global wind speed dispersion in Area III is generally smaller than that in Area I, but it is larger than the global wind speed dispersion in Area II and IV. When the wind direction is NWW, the global wind speed dispersion in Area III is the smallest, and the wind speed distribution is the most uniform. The global wind speed dispersions in Area II and IV are generally close, and both are smaller than those in Area I and III.