## 6 Conclusions  
The erosion and wear patterns of pipeline elbows under different structural parameters were analysed in this study. The following conclusions were obtained:  
1. The degree of influence of each structural parameter on the erosion wear in descending order is as follows: bending angle, bending diameter ratio and spatial angle. 2. With the increase in the bending diameter ratio, the erosion wear rate of the pipeline structure gradually decreases. With the increase in the bending angle of the elbow, the maximum erosion rate of the pipeline elbow changes less before \(90^{\circ}\) and gradually  
Figure 28: Comparison of erosion rates for two pipelines. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Pipeline Type** & \begin{tabular}{c} **Upper End Elbow** \\ **Erosion Rate** \\ **kg/(m\({}^{2}\cdot\)s)** \\ \end{tabular} & \begin{tabular}{c} **Lower End Elbow** \\ **Erosion Rate** \\ **kg/(m\({}^{2}\cdot\)s)** \\ \end{tabular} & \
\begin{tabular}{c} **Maximum** \\ **Erosion Rate** \\ **kg/(m\({}^{2}\cdot\)s)** \\ \end{tabular} &
\begin{tabular}{c} **Reduction from** \\ **Original** \\ **Structure** \\ \end{tabular} \\ \hline Typical pipeline structure & \(2.34\times 10^{-6}\) & \(2.47\times 10^{-6}\) & \(2.47\times 10^{-6}\) & — \\ T-type blind through short header pipe & \(1.98\times 10^{-7}\) & \(5.14\times 10^{-7}\) & \(7.19\times 10^{-7}\) & \(70.89\%\) \\ T-type blind through long header pipe & \(3.43\times 10^{-7}\) & \(3.24\times 10^{-7}\) & \(3.81\times 10^{-7}\) & \(84.57\%\) \\
70 mm round head blind pipe & \(3.12\times 10^{-7}\) & \(5.86\times 10^{-7}\) & \(7.81\times 10^{-7}\) & \(68.38\%\) \\
100 mm round head blind pipe & \(3.02\times 10^{-7}\) & \(5.29\times 10^{-7}\) & \(1.15\times 10^{-6}\) & \(53.44\%\) \\ Minispherical & \(4.04\times 10^{-7}\) & \(2.83\times 10^{-7}\) & \(4.04\times 10^{-7}\) & \(83.64\%\) \\ Mesopherical & \(5.94\times 10^{-7}\) & \(2.67\times 10^{-7}\) & \(5.94\times 10^{-7}\) & \(75.95\%\) \\ Hemispherical & \(4.39\times 10^{-7}\) & \(6.58\times 10^{-7}\) & \(2.19\times 10^{-6}\) & \(11.34\%\) \\ Spherical & \(1.21\times 10^{-6}\) & \(2.43\times 10^{-7}\) & \(1.21\times 10^{-6}\) & \(51.01\%\) \\ Stripe & \(8.82\times 10^{-7}\) & \(1.47\times 10^{-6}\) & \(5.88\times 10^{-6}\) & \(-138.06\%\) \\ Striation & \(6.63\times 10^{-7}\) & \(1.99\times 10^{-6}\) & \(1.33\times 10^{-5}\) & \(-438.46\%\) \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Erosion rate. increases beyond 90\({}^{\circ}\). When the space clamping angle increases, the maximum erosion rate of the pipeline structure gradually decreases. 3. The bend to increase the blind tube can effectively reduce the erosion rate and slow down the erosion effect. An appropriate increase in the length and volume of the blind pass tube can also reduce erosion wear at the bend. Spherical bends make the particle distribution more uniform. The spherical diameter of the smaller bend has a greater anti-erosion effect than the larger diameter of the spherical bends. The maximum erosion rate of the corrugated pipe is higher than that of other structures, but its low erosion rate distribution area is wider, and the peak is more distributed in point form. 4. A new structure based on the bionic structure for optimizing the erosion resistance of pipe elbows is proposed. The influence of different structure sizes and other factors at the bends in resisting erosion is studied comparatively. It is then verified that the corrugated structure has a better erosion-resistance effect. This provides a reference for the further design and optimization of the pipeline. 5. As a result of the oil and gas extraction process, multiple factors working together have an impact on bend erosion wear. The method of controlling a single variable used in this study has caused the erosion wear numerical simulation results to deviate from the experimental, and even actual, working conditions. In subsequent studies, more situations will be considered to ensure that the numerical simulation results are more accurate.