Deformation and motion characteristics of bubble in swirling flow field

To investigate the occurrence mechanism and motion law of bubble deformation in a swirling flow field, the bubble breakup process was studied experimentally using high-speed camera technology. By defining the equivalent diameter of bubbles, an evaluation model for the breakup time of bubbles in the swirling flow field was derived, and the relationship between bubble breakup time and Weber number was obtained. Additionally, the computational fluid dynamics （CFD） theory was applied to simulate and verify the interaction between bubbles and the flow field.The results showed that bubbles were impacted by the liquid flow at the inlet, resulting in slight wrinkles on their surfaces with a small degree of deformation. As the bubbles entered the swirling flow field, the degree of deformation intensified under the combined action of shear force and centrifugal force: bubble necks were formed at the edges of the bubbles, and depressions appeared inside the bubbles, followed by breakup. At the moment of bubble breakup, the surface area ratio was 2.69, and the average surface velocity was 2.1 times the initial incident velocity. After breakup, the values of various characteristic parameters gradually decreased and tended to stabilize. Based on these observations, the migration characteristics and deformation law of bubbles in the swirling flow field were obtained. The research provides a reliable theoretical basis and experimental reference for the exploration of bubble morphology changes and their migration characteristics in the swirling flow field.