Simulation of liquid film effects on vortex formation with gas-liquid two-phase flow around a spherical particle

Recently, most research on gas-liquid flow through packed particulate beds has focused on macro scale parameters, such as the bed pressure drop, liquid holdup, and so on. However, very few efforts have focused on the local flow behavior, which is essential for understanding the concept of flow mal-distribution. Therefore, in this study, the CFD (Computational Fluid Dynamics) - VOF (Volume-of-Fluid) method, which is able to track the position of the interface between multiphase fluids and the effects of surface tension, was employed to investigate the gas-liquid two-phase flow across a spherical particle. By observing the whole process of the liquid flow pattern as well as vortex production, we found that the gas vortex was strongly related to the liquid flow pattern, whose shape and scale vary with the liquid flow stages. Moreover, parametric studies were conducted to determine how the vortices beneath and on the surface of the particle change. The fully revealed mechanism of vortex formation on the bottom of a particle could significantly benefit the understanding of gas-liquid flow hysteresis inside packed beds and thus be applied to improve the reactor performance. Figure reveals the whole process of vortex generation, developing and elapse beneath the particle [Display omitted] •The generation and development of vortex are related to liquid flow pattern, the scale of it vary with liquid flow stages.•The breakage extent of the liquid film is mainly affected by the gas velocity rather than liquid velocity.•The vortex radius increases with the increment of both gas and liquid velocities stage.