Erosion of oval elbows in turbulent particulate natural gas flow with different aspect ratio of cross-sections

Abstract

In this study, the erosion of the oval elbow duct pipe due to the natural gas–solid particles in the turbulent flow (k-epsilon) by (CFD) is investigated with specific consideration to the effect of the oval aspect ratio. The natural gas–solid particle turbulent flow is simulated by utilizing the two-way coupling, Eulerian–Lagrangian approach; while an enhanced wall treatment method is used because the flow has unique behavior when is close to the walls. Effects of most important erosion variable like channel geometry change, natural gas rate, and velocity on the erosion rate in all geometries were evaluated and discussed. Simulation results were verified with existing experimental results of the circular duct. Our results show that the geometry change has a severe effect on the erosion rate, and also the pipe aspect ratio has a considerable effect on the Dean Flow, the particle path line, and finally, the erosion rate of the elbow channel. Particle trajectory shows that the particles have an intense focus on inside the convex wall of the high-aspect-ratio cross-sections. Our result shows that the erosion will be decreased by reducing the aspect ratio to 0.4.