Abstract The present work aimed to conduct the visualization study on the effect of the ethylene glycol concentration on the interfacial behavior of successive droplets during the impacting onto a horizontal hot solid surface. The tested liquid droplets were pure water and two ethylene glycol-water mixtures, which contain 10% and 20% of ethylene glycol. A polished cylindrical plate of stainless steel (SUS 304), with the surface roughness of 0.06 μm, was utilized as a solid surface. The surface varies for temperatures of about 110 °C–240 °C. The detailed phenomena during the droplet impact were recorded by using a high-speed video camera with the frame speed of 2000 fps and the resolution of the 1024 × 768. In addition, an own developed image processing technique was also implemented to obtain the quantitative parameters, such as the spreading ratio and the apex height during the droplet impacting onto a hot solid surface. As a result, the interfacial dynamics of the successive droplets were clarified. The addition of the concentration of ethylene glycol leads to the decrease of droplet oscillation during the spreading phase and delays both the bubble formation and the presence of secondary droplets. In addition, the research also reveals that the presence of the second droplet successfully improves the wetting area of the droplet.

中文翻译：

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乙二醇浓度对连续液滴撞击水平热固体表面的界面动力学的影响

摘要 目前的工作旨在对乙二醇浓度对连续液滴撞击水平热固体表面时的界面行为的影响进行可视化研究。测试的液滴是纯水和两种乙二醇-水混合物，分别含有 10% 和 20% 的乙二醇。表面粗糙度为 0.06 μm 的不锈钢（SUS 304）抛光圆柱板用作固体表面。表面在大约 110 °C–240 °C 的温度范围内变化。使用帧速度为2000 fps、分辨率为1024 × 768的高速摄像机记录了液滴撞击过程中的详细现象。此外，还采用了自己开发的图像处理技术来获取定量参数, 例如液滴撞击热固体表面期间的扩散率和顶点高度。结果，澄清了连续液滴的界面动力学。乙二醇浓度的增加导致扩散阶段液滴振荡的减少，并延迟了气泡的形成和二次液滴的存在。此外，研究还表明，第二个液滴的存在成功地提高了液滴的润湿面积。乙二醇浓度的增加导致扩散阶段液滴振荡的减少，并延迟了气泡的形成和二次液滴的存在。此外，研究还表明，第二个液滴的存在成功地提高了液滴的润湿面积。乙二醇浓度的增加导致扩散阶段液滴振荡的减少，并延迟了气泡的形成和二次液滴的存在。此外，研究还表明，第二个液滴的存在成功地提高了液滴的润湿面积。