Numerical investigation of erosion phenomena in curved ducts

Solid particle erosion is a complex phenomenon that depends on many factors such as particle and flow characteristics, type of material being eroded and flow Geometry. Bends, which are integral parts of piping system, are vulnerable in erosive environments because solid particles can not follow the streamlines of the flow and impinge on the pipe wall. Thus, this paper investigates numerically the erosion phenomenon that occurs in 90 degrees and 180 degrees curved ducts. The numerical calculations are performed by Eulerian approach for gas-phase taking into account the mutual effects of the solids on the gas and Lagrangian approach for dispersed-phase. The effects of particle rotation and lift forces are included in the particle tracking model while the effect of inter-particle collisions is neglected. The erosion prediction model comprises three stages: flow modeling, particle tracking and erosion calculations. Many of the previous published data are taken to validate the three stages of the present model. Comparisons between predicted penetration rate and published experimental data show a good agreement. The effects of bend orientation, inlet gas velocity, bend dimensions, loading ratio and particle size on the penetration rate are also simulated. The present results show that the penetration rate increases as the curvature ratio, particle diameter, inlet gas velocity increase and as the mass loading, ratio and pipe diameter decrease. Furthermore, the present results show also that the bend orientation and flow direction have no significant effect on the penetration rate.