## 2 Numerical Model and Parameters  
### Computational Domain and Grid Settings  
The greenhouse dimensions were based on five commonly used sizes in the alpine cold regions of China, with an east-west length of 60 m. While the spans and ridge heights varied, the ratios of north wall height to ridge height and ridge height to span remained constant. The greenhouse model features a rear roof inclination of approximately 42\({}^{\circ}\) (\(\alpha\)) and a front roof inclination of approximately 30\({}^{\circ}\) (\(\theta\)). The north wall height is denoted as \(H_{1}\), the ridge height as \(H_{2}\), the horizontal projection of the rear slope as \(B_{1}\), and the north-south span as \(B_{2}\), as detailed in Table 1. The surface profile of solar greenhouse is shown in Figure 1. Since the greenhouse dimensions were derived from practical applications, strict equal proportions were not maintained, resulting in localized variations in the model. The computational domain was enlarged by three times the model span before the model in the X-axis direction, six times the model span after the model and four times the model length in each of the left/right directions in the Z-axis direction, and more than five times the model height in the Y-axis direction, as shown in Figure 2.  
An unstructured grid methodology was employed, with grid sizes determined according to reference [11]. The computational domain featured a maximum grid size of 5 m, while the greenhouse surface grid was refined to 0.3 m [11]. Given the significant gradients in velocities, pressures, and other physical quantities near the greenhouse, a boundary layer was implemented. The initial layer had a thickness of 0.1 m with a growth rate of 1.2, resulting in a boundary layer thickness of 0.74 m. Beyond the boundary layer, the bulk mesh had a growth rate of 1.08, yielding a total grid count exceeding \(10^{7}\). The closer the mesh quality is to 1 [11], the higher the quality of the mesh. More than 80% of the total number of grids for all conditions have a mass of not less than 0.8, with a minimum mass of 0.4.  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline
**Span (m)** & \(H_{1}\) **(m)** & \(H_{2}\) **(m)** & \(B_{1}\) **(m)** & \(B_{2}\) **(m)** & \(\alpha\) (\({}^{\circ}\))** & \(\theta\) (\({}^{\circ}\)) & \(H_{1}\)/\(H_{2}\) & \(H_{2}\)/\(B_{2}\) \\ \hline
8 & 2.8 & 3.9 & 1.2 & 8 & 43 & 30 & 0.7 & 0.49 \\
10 & 3.4 & 4.8 & 1.6 & 10 & 41 & 30 & 0.7 & 0.48 \\
12 & 4 & 5.7 & 1.9 & 12 & 42 & 29 & 0.7 & 0.48 \\
14 & 4.5 & 6.6 & 2.4 & 14 & 41 & 30 & 0.7 & 0.47 \\
16 & 5 & 7.5 & 2.8 & 16 & 42 & 30 & 0.7 & 0.47 \\ \hline \end{tabular}
\end{table}
Table 1: Dimensions of different greenhouse models.  
Figure 1: Surface profile of solar greenhouse.  
Figure 2: Size of calculation domain under \(0^{\circ}\) wind angle. Note: X-axis is parallel to the direction of incoming wind, Y-axis is height direction, Z-axis is perpendicular to the direction of incoming wind; \(10\)\(L\), \(9\)\(W\), \(5\)\(H\) are the length, width, and height of the calculation domain, respectively; \(L\) is the length of the greenhouse profile perpendicular to the incoming flow, m; \(W\) is the length of the greenhouse profile parallel to the incoming flow, m; and \(H\) is the height of the greenhouse, m.