冲击作用下液滴在环境液体中的变形破碎行为

采用基于液-液体系的坠落实验装置对冲击作用下单个液滴在环境液体中的变形破碎行为进行了实验研究。针对高速摄影捕捉到的5种液滴典型变形破碎模式进行了定量化考察和规律性分析。结果表明，液滴初始直径、液滴与环境液体的密度比和粘度比、界面张力系数以及坠落高度等实验参数相互组合可以得到相似的实验结果，其中We数是区分液滴变形破碎模式的关键参数。进一步研究液滴变形破碎模式与无量纲参数的依赖关系发现，在1 < We < 700、0.001 < Oh < 0.005的实验条件范围内，液滴变形破碎模式与Oh数无明显依赖关系，而在We数相近情况下，液滴变形破碎模式呈现明显的相似性。

Deformation and breakup behaviors of a drop in ambient liquid under impact

In this study, we carry out an experimental investigation of the behaviors as well as the mechanism of the liquid-liquid drop deformation and breakup process following an impact. With high speed photography, five distinct deformation and breakup modes are captured, for which the key factors that dominate the transition are quantitatively analyzed. The results show that similar deformation behaviors may occur for a proper combination of drop sizes, density ratios between drop and ambient fluid, interfacial tensions and free falling heights. Two non-dimensional parameters, i.e. Weber number (We) and Ohnesorge number (Oh), are calculated to estimate these effects. It is found that, similar deformation behaviors may have a strong correlation with the Weber number. After a further survey of the test range of present study (1 < We < 700, 0.001 < Oh < 0.005), it can be concluded that the deformation and breakup pattern is barely affected by the Ohnesorge number, whereas exhibits a strong dependence on the Weber number.