## 3. Experimental Results and Discussion
### Orthogonal Simulation Results and Analysis
#### 3.1.2 Pressure Distribution within the Pressurized Tube  
Pressure distribution contour plots within the pressurized tube for different structural configurations were obtained through post-processing using CFD-Post(14.0) software, as shown in Figure 5. In the straight segments of the pressurized tubes, the pressure distribution is uniform and pressure losses are relatively small, with consistent upper and lower pressure. When corrugations appear, pressure changes occur. The central pressure decreases, while the pressure at the pressurized tube wall increases. The depth of the corrugations affects the pressure changes, with deeper corrugations resulting in more pronounced pressure variations. Pressure losses within the pressurized tube also increase with longer pressurized tube lengths and a higher number of corrugations. As corrugation width increases, the pressure changes within the corrugated section first decrease and then increase. Through variance analysis, it is evident that corrugation depth, corrugation width, corrugation count, and pressurized tube length have \(p\)-values of less than 0.05 for both the pressure difference and distribution uniformity coefficient, indicating their significant influence. Furthermore, the primary and secondary order of impact on pressure difference is pressurized tube length > corrugation count > corrugation width > corrugation depth, while the primary and secondary order of impact on the distribution uniformity coefficient is corrugation depth > corrugation width > corrugation count > pressurized tube length. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & **Source of Variation** & **Sum of Squares** &
\begin{tabular}{c} **Degrees of** \\ **Freedom** \\ \end{tabular} & **Mean Square** & **F-Value** & \(p\)**-Value** \\ \cline{2-6}
**Variance Analysis** & Wave Width & 457.188 & 3 & 152.396 & 0.955 & 0.049 \\
**of Pressure Loss** & Wave Depth & 228.188 & 3 & 76.063 & 0.477 & 0.037 \\  & Wave Number & 5746.187 & 3 & 1915.396 & 12.004 & 0.025 \\  & Pipe Length & 16,091.187 & 3 & 5363.729 & 33.615 & 0.008 \\ \hline  & **Source of Variation** & **Sum of Squares** &
\begin{tabular}{c} **Degrees of** \\ **Freedom** \\ \end{tabular} & **Mean Square** & **F-Value** & \(p\)**-Value** \\ \cline{2-6}
**Variance Analysis** & Wave Width & 0.029 & 3 & 0.01 & 0.710 & 0.006 \\
**Uniformity** & Wave Depth & 0.027 & 3 & 0.009 & 0.667 & 0.026 \\
**Coefficient** & Wave Number & 0.052 & 3 & 0.017 & 1.271 & 0.042 \\  & Pipe Length & 0.047 & 3 & 0.016 & 1.151 & 0.045 \\ \hline  & & & & & & \\ \end{tabular} Note: \(p\) < 0.001 (highly significant), \(p\) < 0.05 (significant).  
\end{table} 
Table 5: Analysis of variance for experimental results. By conducting variance analysis on the experimental results and determining the primary and secondary orders of the factors' impact on pressure loss and distribution uniformity coefficient, a further single-factor mean analysis was performed to determine the optimal structural parameters of the pressurized tube. The results of the single-factor mean analysis are presented in Table 6.  
In the context of pressure loss, lower pressure loss results in reduced energy loss in the seeding system, indicating better seeding performance. Based on the comprehensive analysis of single-factor mean pressure loss, the minimum pressure loss value was achieved with a corrugation depth of 4 mm, corrugation width of 50 mm, corrugation count of 4, and a pressurized tube length of 700 mm. However, having too few corrugations can lead to an uneven airflow distribution within the vane, resulting in decreased seed distribution uniformity. A pressurized tube that is too short may not facilitate the uniform mixing of air and seeds, leading to reduced seed distribution uniformity. A shallow corrugation depth may not adequately disperse the two-phase airflow of air and seeds, reducing the distribution uniformity of the seeding system. Figure 5: Pressure distribution cloud map inside the baffle.