Investigation on Foaming Performance of a Swirl-Venturi Micrometer Bubble Generator Based on the Coupling CFD-PBM Method

To further reduce microbubble size and deviation, this study investigated the foaming performance of a novel swirl-venturi microbubble generator featuring four tangential inlets using a coupled CFD-PBM model. The design utilized the tangential inlets to induce gas phase and generate a swirling flow that increased the throat region’s maximum velocity and significantly enhanced the turbulence intensity in the throat region, effectively promoting bubble fragmentation. The results showed that the average bubble diameter was reduced by up to 31.45% compared to conventional designs. Moreover, increasing the divergent angle not only boosted the inlet pressure but also significantly increased the proportion of microbubbles in the 20–50 μm range. Empirical correlations between structural parameters and forming performance were established through ANOVA analysis. These findings provide valuable guidance for the efficient design and scale-up of microbubble generators in industrial applications and offer a solid theoretical foundation for optimizing foaming processes.