# The Influence of Mountain Height and Distance on Shape Factor of Wind Load of Plastic Tunnel
## 5 Conclusions  
In this paper, three models featuring different mountain heights have established by numerical simulation to analyze the influence of mountain height and mountain distance on wind pressure distribution and the shape factor of the wind load on the surface of a greenhouse. The sine model was chosen as the contour equation of the mountain model. Therefore, the conclusions are mainly applicable to the mountain in the form of a sine curve. The main conclusions are as follows:  
(a) When the inflow direction is parallel to the mountain valley, regardless of the distance between the mountains and the height of the mountain, the distribution law of wind pressure on the surface of the greenhouse located in a valley is similar to that for a greenhouse on a plain area, and only the values of positive/negative pressure coefficients are different;  
(b) When the greenhouses are located in valley areas with different mountain heights, the valley will have a greater influence on the shape factor of the wind load on areas LW3/RW3, B, T1 and T3 of the greenhouse. The mountain will weaken the positive pressure on the windward side, which is beneficial to the windward area F. The suction on each surface of the greenhouse decreases with the increase in the distance \(d\) between the greenhouse and the mountain, while the shape factor of the wind load on each pressure area increases with the increase in the distance \(d\);  
(c) When the ratio of the distance \(d\) to the height of the mountain \(H\) is less than 5, that is, \(d/H\) < 5, the mountain will have a large influence on the shape factor of the wind load of the greenhouse. When \(d/H\) > 10, the influence of the mountain's height on the shape factor of wind load will be negligible;  
(d) A computational model for deriving the shape factor of the wind load is here proposed, and this can be used to calculate the wind load acting on the surface of a greenhouse in a valley area, and it can also provide data support for the revision of load codes regarding the design of greenhouse structures.  
Conceptualization, J.X. and Z.L.; software, G.H. and X.R.; data curation, Z.S. and J.X.; writing--original draft preparation, X.R. and S.D.; writing--review and editing, J.X.; visualization, G.H. and J.X. All authors have read and agreed to the published version of the manuscript.  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline
**Coefficient** & **F** & **B** & **LW1/RW1** & **LW2/RW2** & **LW3/RW3** & **T1** & **T2** & **T3** \\ \hline \(A\) & 0.495 & \(-\)0.271 & \(-\)0.887 & \(-\)0.570 & \(-\)0.236 & \(-\)0.245 & \(-\)1.217 & \(-\)0.329 \\ \(C\) & 0.419 & 0.957 & 1.205 & 1.076 & 0.972 & 0.863 & 1.020 & 0.925 \\ \(D\) & 0.585 & 0.646 & 0.675 & 0.661 & 0.632 & 0.670 & 0.672 & 0.676 \\ Correlation coefficient \(R^{2}\) & 0.973 & 0.995 & 0.993 & 0.996 & 0.995 & 0.992 & 0.941 & 0.993 \\ \hline \end{tabular}
\end{table}
Table 1: The fitting coefficients of the model in each area of the greenhouse.  
**Funding:** This research work was supported by the National Natural Science Foundation of China (U20A2020), Beijing Innovation Consortium of Agriculture Research System (BAIC01-2023-20) and Ministry of Education of the People's Republic of China (C21 JB0100060).  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** The data presented in this study are available in article.  
**Conflicts of Interest:** The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.