Li, R.; Maestri, R.; Lecrivain, G. CFD simulation of aerosol separation in rising Taylor bubbles in vertical tube; 98% efficiency in constricted channel
CFD simulation of aerosol separation in rising Taylor bubbles - Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf, HZDR
CFD simulation of aerosol separation in rising Taylor bubbles
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Li, R.; Maestri, R. ; Lecrivain, G.
Wet scrubbing is an important gas purification method in which aerosol particles in the gas phase can migrate across the gas-liquid interface into the liquid phase and be removed. Compared to free-rising bubbles, Taylor bubbles in confined tubes have a more stable shape and a clearer flow structure, making them suitable for studying the mechanism of particle migration from the bubble into the liquid phase. This study employs a three-phase (gas-liquid-solid) numerical simulation method to investigate the separation behavior of particles within rising Taylor bubbles in a vertical tube. The gas-liquid two-phase flow field was simulated using a Volume of Fluid (VOF) method in OpenFOAM, while the particles were tracked using the Lagrangian Particle Tracking (LPT) method. First, the shape, rise velocity, liquid film thickness, and internal and external recirculation structures of the Taylor bubble were validated. The results indicate that the numerical model can effectively reproduce the main hydrodynamic characteristics of the Taylor bubble, providing a reliable foundation for subsequent particle transport analysis. Subsequently, this study quantitatively investigated the effects of bubble length, particle diameter, and particle density on separation efficiency. The results indicate that when the initial number of particles reaches 104, the separation efficiency exhibits good statistical stability. As bubble length increases, particle separation efficiency decreases, conversely, as particle diameter and particle density increase, particles are more likely to enter the liquid phase, thereby improving separation efficiency. Compared with freely rising bubbles, Taylor bubbles exhibit lower separation efficiency for the same rise time but demonstrate higher particle removal capacity for the same rise distance. Furthermore, the periodic constrictions in the wavy channel enhance bubble deformation and internal particle motion, increasing the separation efficiency from 89.0% in a straight tube to 98.0%. The results indicate that Taylor bubbles and constricted channel geometries have potential application value in the wet scrubbing of aerosols.
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