On the correlation between particle dynamics and erosion pattern in pipe bends: Insights via numerical simulation

Erosion poses a significant threat to gas transportation pipelines, particularly at pipe bends where sand particle impingement can lead to equipment malfunction and pipeline failure. In this work, we employ a one-way coupling simulation approach for flow–particle interactions across various bend geometries to understand sand dynamics in gas pipelines. First, Large-Eddy Simulations (LESs) are conducted to analyze flow patterns in 45°, 75°, 90°, and 180° pipe bend geometries with gas flow velocities of 8.5 m/s at the inlet. Our LES reveals that an energetic separation forms near the bend apex. Second, particle trajectory analysis indicates that particle impingement predominantly occurs downstream of the pipe bend across all geometries. Third, experimental studies utilizing the paint removal technique are also performed to correlate with the numerical prediction. Comparing the numerical results with the corresponding experimental observations, our results show that complex flow patterns control particle trajectories and potential erosion sites in bends. Finally, a detailed statistical analysis using probability density functions of particle velocity and rebound angle provides quantitative insights into particle behavior within each bend. Our study reveals distinct trends depending on the bend angle (α). This research develops a comprehensive engineering approach to predict particle trajectories and particle–wall interactions within pipe bends, ultimately informing erosion prediction.