School of Mechanical Engineering , Shiraz University , Shiraz 71936-16548 , Iran.
School of Civil & Environmental Engineering , UNSW Water Research Laboratory , 110 King Street , Manly Vale , New South Wales 2093 , Australia.
Langmuir. 2018 May 1;34(17):5149-5158. doi: 10.1021/acs.langmuir.8b00625. Epub 2018 Apr 17.
The spreading and rebound patterns of low-viscous droplets upon impacting spherical solid surfaces are investigated numerically. The studied cases consider a droplet impinging onto hydrophobic and superhydrophobic surfaces with various parameters varied throughout the study, and their effects on the postimpingement behavior are discussed. These parameters include impact Weber number (through varying the surface tension and impingement velocity), the size ratio of the droplet to the solid surface, and the surface contact angle. According to the findings, the maximum spreading diameter increases with the impact velocity, with an increase of the sphere diameter, with a lower surface wettability, and with a lower surface tension. Typical outcomes of the impact include (1) complete rebound, (2) splash, and (3) a final deposition stage after a series of spreading and recoiling phases. Finally, a novel, practical model is proposed, which can reasonably predict the maximum deformation of low Reynolds number impact of droplets onto hydrophobic or superhydrophobic spherical solid surfaces.
本文数值研究了低粘性液滴撞击球形固体表面时的铺展和回弹模式。研究案例考虑了液滴撞击具有不同参数的疏水性和超疏水性表面，讨论了这些参数对撞击后行为的影响。这些参数包括冲击韦伯数（通过改变表面张力和撞击速度）、液滴与固体表面的大小比，以及表面接触角。根据研究结果，最大铺展直径随冲击速度增加而增加，随球体直径增加而增加，随表面润湿性降低和表面张力降低而增加。撞击的典型结果包括（1）完全回弹，（2）飞溅，以及（3）在一系列铺展和回弹阶段后进入最终沉积阶段。最后，提出了一种新的实用模型，该模型可以合理预测低雷诺数液滴撞击疏水性或超疏水性球形固体表面的最大变形。
