The flow of dispersed microbubbles was studied with an Eulerian–Lagrangian technique using large eddy simulation to predict the continuous liquid flow and Lagrangian tracking to compute bubble trajectories. The model fully accounts for bubble coalescence and breakup and was applied to horizontal and vertical channel flows. With low levels of turbulence, gravity in horizontal, and lift in vertical, channel flows govern the bubble spatial and collision distribution. When turbulence is sufficiently high to, at least partially, oppose bubble preferential concentration, more uniform collision and coalescence distributions are found, although these remain peaked near the wall in both configurations. Almost 100% coalescence efficiency was always found, due to bubbles colliding along similar trajectories, with breakup only recorded in a flow of low surface tension refrigerant R134a. Models like this can provide the required quantitative understanding of the microbubbles complex behavior, as well as supporting the development of more macroscopic modeling closures.

中文翻译：

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使用大涡模拟和拉格朗日跟踪的微气泡聚结和破裂的计算模型

用欧拉-拉格朗日技术研究了分散的微气泡的流动，使用大涡模拟来预测连续的液体流动，并使用拉格朗日跟踪来计算气泡的轨迹。该模型充分考虑了气泡的聚结和破裂，并应用于水平和垂直通道流动。在低水平的湍流，水平的重力和垂直的升力的情况下，通道流控制气泡的空间和碰撞分布。当湍流足够高以至少部分地反对气泡优先集中时，尽管在两种构造中它们都在壁附近保持峰值，但是发现更均匀的碰撞和聚结分布。由于气泡沿相似的轨迹碰撞，总是发现几乎100％的聚结效率，仅在低表面张力制冷剂R134a的流动中才记录有破裂。这样的模型可以提供对微气泡复杂行为的必要定量理解，并支持开发更多的宏观建模闭包。