CFD-DEM coupling simulation of gas–solid two-phase powder feeding path in a powder feeding system

Aiming at common challenges of unstable flow regime, easy deposition and uneven distribution in the pneumatic conveying of fine powders, this paper adopts coupled simulation of Computational Fluid Dynamics and Discrete Element Method (CFD-DEM) to systematically investigate the effects of carrier gas velocity and hopper arch height on the flow characteristics of micron-sized powders in a thin tube and bend system. A three-dimensional refined model is established to investigate the particle velocity distribution, collision frequency, energy dissipation, and spatiotemporal evolution of the particle concentration field under varying operational parameters. Results indicate that a carrier gas velocity within optimal range of 7–9 m/s effectively balances conveying efficiency and energy consumption, while simultaneously reducing particle deposition and pipe wall erosion. Furthermore, optimizing the hopper arch height to 1.62 mm enhances the uniformity of the powder flow field by 31% and reduces collision-induced energy loss by 45%. This study reveals the microscopic mechanism of flow and energy dissipation of fine powders in confined spaces, provides a theoretical basis for the design and parameter optimization of high-performance precision powder feeding devices, and has reference value for improving the stability and economy of powder conveying in fields such as additive manufacturing and surface engineering.