壁面浸润性对液滴撞击液面行为的影响

Effect of wall wettability on droplet impacting on limited liquid surface

研究壁面浸润性对液滴撞击液面行为的影响.采用纳米喷涂方法,制备内壁具有超亲水、疏水、超疏水浸润性的3种试管.采用高速摄影机记录不同浸润性试管内液滴撞击凹凸气液界面的实验现象.利用镜面成像原理校准液滴撞击点,使液滴撞击试管液面正中央.实验结果表明:壁面越疏水,产生射流现象的撞击高度范围越大.将撞击形成的凹坑简化成圆锥,对液滴撞击液面前后状态进行能量分析,解释了壁面越疏水液滴撞击液面越容易产生射流的实验现象.

The effect of wall wettability on droplet impacting on limited liquid surface was researched.Three types of test tubes with inner wall behaving super-hydrophilic,hydrophobic and super-hydrophobic were prepared by nano-spraying technology.The experimental phenomena of droplet impacting on these water-air interfaces were recorded by high-speed camera.In the experiment,the principle of specular imaging was used to make sure that droplet could impact the center of the liquid surface in test tube.The experimental results showed the impacting height range to form jetting enlarged with the enhancement of surface wettability.This paper utilized energy analysis based on the simplified model that the cavity formed by droplet impacting was treated as a cone.This analysis explained that the droplet jetting could be generated more easily while the wall hydrophocity was enhanced.