We perform quantitative visualization experiments on the vertical (z‐direction) motion of a spherical solid particle being lifted off a horizontal flat bottom due to laminar fluid flow generated by a revolving impeller. Describing the observed motion of the particle in terms of a constant vertical hydrodynamic force overcoming gravity and the lubrication force has limited success. For this reason, we hypothesize that the hydrodynamic force on the particle quickly increases with its distance from the bottom. This hypothesis is supported by detailed numerical simulations of the flow around the particle. Integrating the equation of motion of the sphere with the vertical hydrodynamic force as a linear function of z derived from simulations provides an adequate description of the experimentally observed vertical motion of the particle.

中文翻译：

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层流流体从平坦的底部升起固体球体

由于旋转叶轮产生的层流，我们对球形固体颗粒的垂直（z方向）运动从水平平坦底部提起进行了定量可视化实验。以恒定的垂直流体动力克服重力和润滑力来描述观察到的颗粒运动有限，仅能获得成功。因此，我们假设粒子上的流体动力会随着其与底部的距离而迅速增加。该假设得到粒子周围流动的详细数值模拟的支持。将球体的运动方程与垂直流体动力作为z的线性函数进行积分 从模拟中得出的结论对实验观察到的粒子的垂直运动提供了充分的描述。