On the splashing of high-speed drops impacting a dry surface
On the splashing of high-speed drops impacting a dry surface
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DOI：
10.1017/jfm.2020.168
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发表时间：
2020-06-10
影响因子：
3.7
通讯作者：
Bansmer, Stephan E.
中科院分区：
文献类型：
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作者：
Burzynski, David A.;Roisman, Ilia, V;Bansmer, Stephan E.
当液滴以高速撞击干燥表面时，它雾化成二次液滴。这些小液滴是由两种类型的飞溅之一产生的：要么是由表面扩展边缘的迅速飞溅，要么是由从表面悬浮的薄电晕飞溅。本研究采用多台高分辨率相机，通过实验研究了飞溅机制，并描述了高韦伯数和雷诺数下两种飞溅类型的结果。我们表明，迅速飞溅的瑞利-泰勒不稳定性的快速推进的液体薄层和确定的边界定义这个飞溅制度，这使我们能够区分提示电晕飞溅。此外，我们提供了一个表达式来估计产生二次液滴的经过时间，然后在Riboux & Gordillo的理论（Phys. Rev. Lett.，第113（2）卷，2014，024507）。这种理论方法与飞溅结果的详细量化一起使我们能够完全预测两种飞溅类型的结果，包括二次液滴的平均尺寸、速度和总喷射体积。这里提出的详细模型确实可以用来更准确地理解，解释和预测在几个应用程序中的基本物理。
When a drop impacts a dry surface at high velocity, it atomises into secondary droplets. These small droplets are generated by one of two types of splashes: either by a prompt splash from the spreading rim at the surface or by a thin corona splash, which levitates from the surface. This study investigates the splashing mechanisms experimentally using multiple high-resolution cameras and characterises the outcome of both splashing types at high Weber and Reynolds numbers. We demonstrate that the prompt splash is well described by the Rayleigh-Taylor instability of the rapidly advancing liquid lamella and determine the boundaries defining this splashing regime, which allows us to distinguish the prompt from the corona splash. Furthermore, we provide an expression to estimate the elapsed time during which the secondary droplets are generated, which is then implemented in the theory of Riboux & Gordillo (Phys. Rev. Lett., vol. 113 (2), 2014, 024507). This theoretical approach together with detailed quantification of the splashing outcome allows us to completely predict the outcome of both splashing types, which includes the mean size, velocity and total ejected volume of the secondary droplets. The detailed model proposed here can be indeed used to understand, characterise and predict more accurately the underlying physics in several applications.