Numerical analysis of particle shape influence on erosion and flow behavior in a 90-Degree elbow pipe under Solid-Liquid flow

Abstract

In this study, an investigation was conducted to examine the influence of particle shape on erosion behavior in curved pipe systems, a critical component in fluid-conveying systems. A combination of numerical and experimental methodologies was utilized, employing the discrete phase model (DPM) and a coupled computational fluid dynamics-discrete element method (CFD-DEM) to simulate particle–fluid interactions within a 90° elbow pipe. The simulations explored how non-spherical particles, shaped with different degrees of corner sharpness, influence erosion rates, particle dynamics, and localized wear patterns. Experimental observations revealed that maximum erosion was concentrated at the outlet region, where the interaction between particle flow dynamics and pipe geometry intensified localized wear. The erosion rates predicted by numerical DPM simulations were overestimated, particularly in the outlet zone, highlighting the model’s limitations in accurately capturing particle interactions. In contrast, a more accurate representation of localized erosion patterns was provided by CFD–DEM simulations, particularly when non-spherical particles were incorporated. It was demonstrated that angular particles with fewer corners caused more concentrated wear due to higher impact forces, whereas particles with more corners distributed forces more evenly, resulting in less severe erosion. Additionally, Higher particle velocities and kinetic energy intensified impact forces, exacerbating wear, while drag and pressure gradient forces shaped particle trajectories, localizing erosion on the elbow’s outer wall. By integrating these findings, the importance of accounting for particle shape and system geometry in erosion prediction models was emphasized. It was established that the CFD–DEM approach, mainly when applied to non-spherical particles, is reliable for predicting wear in complex geometries, providing valuable insights for designing more durable fluid-conveying systems.