Rajendran S, Jog M A, Manglik R M
Thermal-Fluids and Thermal Processing Laboratory, Department of Mechanical and Materials Engineering, University of Cincinnati, 2901 Woodside Drive, Cincinnati, Ohio 45221-0072, United States.
Langmuir. 2023 Oct 17;39(41):14764-14773. doi: 10.1021/acs.langmuir.3c02185. Epub 2023 Sep 27.
An experimental study is carried out to investigate droplet-film interactions when a drop impinges on a thin stagnant film of the same liquid. The impacting drop causes either liquid deposition or splash, consisting of prompt generation of secondary drops or a delayed process. By varying the drop diameter and impact velocity, measurements are made to characterize the phenomena using five different liquids that are chosen to cover a wide range of liquid properties (viscosity and surface tension). The drop impact dynamics are captured with a high-speed digital camera with real-time, high-resolution image processing. The drop-splash threshold is found to scale with inertial and viscous forces, or Reynolds number (Re), as well as capillary forces, as described by the balance of gravitational and interfacial tension forces, or Bond number (Bo); fluid properties are described by their Morton number (Mo). A correlation, functionally expressed as = ϕ(,), is devised to determine the splash/no-splash (or deposition) boundary, and the predictions for the splash/no-splash outcomes agree well with the experimental outcomes as well as those readily available in the literature.
进行了一项实验研究，以探究当一滴液体撞击到相同液体的静止薄膜时液滴与液膜之间的相互作用。撞击的液滴会导致液体沉积或飞溅，飞溅包括瞬间产生二次液滴或一个延迟过程。通过改变液滴直径和撞击速度，使用五种不同的液体进行测量以表征这些现象，这些液体被选来涵盖广泛的液体特性（粘度和表面张力）。利用高速数码相机结合实时、高分辨率图像处理来捕捉液滴撞击动力学。发现液滴飞溅阈值与惯性力和粘性力（即雷诺数（Re））以及毛细力有关，毛细力由重力和界面张力的平衡（即邦德数（Bo））来描述；流体特性由其莫顿数（Mo）来描述。设计了一个函数表达式为 = ϕ(,) 的关联式来确定飞溅/无飞溅（或沉积）边界，并且对于飞溅/无飞溅结果的预测与实验结果以及文献中现成的结果吻合得很好。
