We perform three-dimensional particle tracking measurements on droplets in a turbulent airflow. The droplets display the well-known preferential concentration of inertial particles, with an additional extreme clustering at the smallest scales. We explain this additional clustering phenomenon theoretically based on a Stokes-flow description of two spheres including their mutual hydrodynamic interaction and a perturbative small-inertia expansion.

中文翻译：

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水动力相互作用驱动的湍流中的液滴极小规模聚集

我们对湍流中的液滴执行三维粒子跟踪测量。液滴表现出众所周知的惯性粒子优先浓度，并在最小尺度上具有额外的极端聚类。我们基于两个球的斯托克斯流描述从理论上解释了这种附加的聚类现象，这两个球包括它们相互的流体动力相互作用和微扰动的小惯性膨胀。