Droplet deformation, oscillation and detachment on a vibrating plate by a controlled airflow
Droplet deformation, oscillation and detachment on a vibrating plate by a controlled airflow
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受控气流在振动板上的液滴变形、振荡和分离
DOI：
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
U. Janoske
中科院分区：
文献类型：
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作者：
Beawer Barwari;S. Burgmann;U. Janoske
在这项工作中，详细的实验研究的流体性质的影响，受到剪切流和谐波表面振动的液滴行为进行。实验在矩形通道中进行，并利用丙烯酸酯通道壁来分析液滴润湿行为。本文研究了在5 - 40 µl液滴体积范围内，气流引起的剪切机制和电磁振动器引起的谐波振动的影响。此外，流体粘度对液滴的运动的影响进行了分析，为水和甘油的混合物的比例范围很广。实验表明，液滴运动开始时的临界体积速度是流体性质和液滴尺寸的函数。液滴体积的增加导致临界体积速度的降低，而液滴的变形增加。相反，增加液滴的甘油含量导致临界体积速度和液滴变形的增加。基于实验观察，液滴运动可以被分类为三种运动模式：（i）液滴形状在很大程度上保持，在后端形成小的尾部，（ii）小液滴在主液滴的后端从尾部分离，（iii）液滴在其整个长度上变形，导致形成膜。
In this work, a detailed experimental study on the influence of fluid properties on the droplet behavior subjected to a shear flow and harmonic surface vibration is conducted. The experiments were executed in a rectangular channel and an acrylic channel wall was utilized to analyze the droplet wetting behavior. Both the effect of shearing mechanism induced by airflow and harmonic vibration induced by an electromagnetic shaker for droplet volumes in the range of 5−40 µl are studied here. Furthermore, the effect of fluid viscosities on the motion of droplets is analyzed for a wide range of water and glycerine mixture ratios. Experiments show that the critical bulk velocity at which the droplet movement begins is a function of fluid properties and droplet sizes. Increasing the droplet volume results in a decrease of the critical bulk velocity, while the droplet deformation increases. On the contrary, increasing the glycerine content of the liquid droplets results in an increase in both the critical bulk velocity and droplet deformation. The droplet movement can be categorized into three motion patterns based on experimental observations: (i) the droplet shape is largely retained with a small tail formation at the rear end, (ii) small droplets detach from the tail at rear end of the main droplet, (iii) the droplet deforms over its entire length resulting in forming of a film.