Mesoscale bubble dynamics play a critical role in governing the overall performance of gas-liquid-solid systems. In this study, the volume of fluid method coupled with a discrete element method is utilized to scrutinize the mesoscale bubble dynamics within a gas-liquid-solid system featuring a dense particle bed. The results reveal that the squeezing effect of the particle bed induces a bubble pairs regime, which causes the bubble collision, coalescence and breakup, thereby generating daughter bubbles. Additionally, the combined influence of large size, flattened shape, off-center collisions and the exists of particles facilitate bubble wakes to transform from closed into asymmetrical open patterns, further causing particles released from bubble wakes. Finally, the high-speed region is predominantly confined to the bubble wake area, resulting in a diminished overall stirring capability compared with two-phase system. The insights obtained from this study shed valuable light on bubble behaviors within gas-liquid-solid systems, offering implications for further study in this field.

中文翻译：

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气-液-固三相流系统中介尺度气泡动力学的 VOF-DEM 数值研究


介尺度气泡动力学在控制气-液-固系统的整体性能方面起着关键作用。在本研究中，利用流体体积法与离散元法耦合来仔细研究具有致密颗粒床的气-液-固系统内的中尺度气泡动力学。结果表明，颗粒床的挤压效应诱导了气泡对状态，导致气泡碰撞、聚结和破裂，从而产生子气泡。此外，大尺寸、扁平形状、偏心碰撞和颗粒存在的综合影响有助于气泡尾迹从闭合转变为不对称的开放图案，进一步导致颗粒从气泡尾迹中释放出来。最后，高速区域主要局限于气泡尾流区域，导致与两相系统相比，整体搅拌能力降低。从这项研究中获得的见解为气-液-固系统中的气泡行为提供了有价值的启示，为该领域的进一步研究提供了启示。