Droplet Coalescence is Initiated by Thermal Motion
Droplet Coalescence is Initiated by Thermal Motion
复制标题
DOI：
10.1103/physrevlett.122.104501
复制
发表时间：
2019-03-13
影响因子：
8.6
通讯作者：
Reese, Jason M.
中科院分区：
文献类型：
--
作者：
Perumanath, Sreehari;Borg, Matthew K.;Reese, Jason M.
两个相同半径R的液滴聚结的经典概念是表面张力驱动初始奇异流。在这封信中，我们表明，使用分子动力学模拟的聚结水nanodroplets，由于热毛细波的存在下，形成单个或多个桥梁后，桥梁生长开始在一个热制度。在这里，由于桥前沿附近的集体分子跳跃，桥在时间上线性膨胀比粘性毛细管速度快得多。只有当桥半径超过类似于根R的热长度尺度l（T）时，才发生向经典流体动力学状态的转变。
The classical notion of the coalescence of two droplets of the same radius R is that surface tension drives an initially singular flow. In this Letter we show, using molecular dynamics simulations of coalescing water nanodroplets, that after single or multiple bridges form due to the presence of thermal capillary waves, the bridge growth commences in a thermal regime. Here, the bridges expand linearly in time much faster than the viscous-capillary speed due to collective molecular jumps near the bridge fronts. Transition to the classical hydrodynamic regime only occurs once the bridge radius exceeds a thermal length scale l(T) similar to root R.