双液滴间距对低速撞击超疏水管壁的动态特性影响研究

The effect of distance between double droplets on the dynamic behaviors of impacting super-hydrophobic tube surfaces with low velocity

中文关键词: 双液滴竖直间距  超疏水管面  同向撞击  异向撞击  断裂

英文关键词: vertical spacing between two droplets  super-hydrophobic tube  rebound  in-phase impact  out-of-phase impact  breakup

中文摘要:

      液滴撞击壁面过程研究应用广泛。采用相界面追踪的Coupled Level Set and Volume of Fluid (CLSVOF)方法对双液滴连续撞击超疏水管面的动态过程进行了数值模拟研究，得到了双液滴撞击后的动态行为特征，并分析了两液滴的竖直间距对液滴撞击结果的影响。研究结果表明：大小相同的双液滴在低速（0.5m/s）撞击接触角为160°的超疏水管壁时，液滴间距为dp时发生同相撞击，液膜在铺展过程中产生中心断裂现象并卷吸气泡，其反弹高度较2dp、3dp时高；液滴间距为2dp、3dp时发生异相撞击，反弹过程中两液滴发生挤压形变，液滴间距较大时还会在反弹阶段出现液膜断裂现象。

英文摘要:

      The research of droplet impact on surfaces is widely used. A coupled level set and volume of fluid (CLSVOF) method was applied to simulate the dynamic process of two successive droplets impacting a super-hydrophobic tube, further, the dynamic behaviors were obtained and the influence of the two droplets spacing was analyzed. Double droplets with the same size successively impacted the super-hydrophobic tube whose contact angle is 160° at low velocity (0.5m/s). When the vertical droplet spacing was dp, ‘in-phase’ impact occurred, center breakup took place and an air bubble was entrained during the spread of the liquid film. In addition, the rebound height is higher than that in 2dp and 3dp cases. The ‘out-of-phase’ impact occurred when the droplet spacing is 2dp or 3dp, the extrusion between the trailing droplet and the film formed by the leading droplet happened at the contact surface. Moreover, the liquid film breakup took place with large vertical spacing between two droplets during the rebound stage.