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    旋流场内气泡形变及运移特性

    Deformation and motion characteristics of bubble in swirling flow field

    • 摘要: 为探究旋流场内气泡形变的发生机理以及运移规律,文中运用高速摄像技术对气泡破碎过程进行实验研究,通过定义气泡的等效直径,推导出旋流场内气泡破碎时间的评价模型,得出气泡破碎时间与韦伯数的关系。此外,运用计算流体动力学(CFD)对气泡与流场间的相互作用进行仿真分析。结果表明,气泡在入口处受到液流的冲击作用,表面出现微小褶皱,变形程度较小。随着气泡进入旋流场,在剪切力和离心力的共同作用下形变程度加剧,气泡边缘产生气泡颈,内部出现凹陷并发生破碎。气泡在破碎瞬间,表面积比为2.69,表面平均速度是初始入射速度的2.1倍,破碎后各项表征参数数值逐渐下降并趋于稳定,得出气泡在旋流场内运移特性及形变规律。研究结论为旋流场内气泡形态变化及其运移特性的探究提供了可靠的理论依据与实验参考。

       

      Abstract: 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.

       

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