Abstract

The complex behavior of multi-scale droplets in Hydro-jet Cyclone (HJC) systems constrains the parametric study of gas–liquid separation and interfacial transfer. To investigate droplet dynamics at a specific scale in swirling flows, this study employed 500-μm simulated droplet particles (SDPs) and examined the effects of inlet gas rate, column height, and cone angle on trajectories, revolution speed, and self-rotation speed using the Computational Fluid Dynamics-Discrete Phase Model (CFD-DPM). The results demonstrate that SDPs exhibit suspended circulation within the cyclone. The suspension zone expands toward the overflow pipe with increasing gas rate and cone angle, but migrates downward with increasing column height. The revolution speed increases from about 50 rad/s to 80 rad/s as inlet gas rate rises, but decays with increasing column height, while cone angle has little influence. The self-rotation speed is driven by near-wall shear, reaching an instantaneous peak of 4500 rad/s at the inlet; after stable suspension, it increases markedly with gas rate, from <3500 rad/s at 12 m/s to 12,000 rad/s at 22 m/s. Inlet gas rate is the dominant factor governing self-rotation, followed by cone angle, whereas column height mainly affects suspension position. This study provides a numerical reference for droplet dynamics in HJC gas–liquid systems.

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