论文标题
冷凝引起的两个相邻液滴的内部对流
Condensation induced internal convection of two neighboring droplets
论文作者
论文摘要
本工作研究了相互作用期间水溶液的两个冷凝液滴的内部流量结构。通过共聚焦微型PIV技术研究了液滴内流体的速度。液滴上的凝结是通过在室温下液滴界面和周围液滴周围的储层液之间造成蒸气压的差异，而无需冷却。液滴上的凝结导致液滴内部溶质浓度的空间变化，从而导致浮力驱动的瑞利对流。单个冷凝液滴内部的流体流动模式本质上是对称的，因为两个相互作用的液滴的流体流动模式本质上是不对称的。相邻的液滴通过两个冷凝液滴之间的蒸气介导的相互作用来影响内部对流。在这里，冷凝液滴从远处感觉到相邻的液滴，而无需任何物理接触。流动模式的不对称性质归因于在相邻液滴存在下液滴的凝结通量分布的修饰。凝结过程中相互作用的液滴观察到的流动模式与蒸发液滴相反。相邻液滴对冷凝液滴内部对流的影响随着液滴之间的分离距离的增加而减少。
The present work investigates the internal flow structure of two condensing droplets of aqueous solution during interaction. The velocity of fluid inside the droplets was investigated by confocal micro-PIV technique. Condensation on the droplets was carried out inside a closed chamber by creating a difference in vapor pressure between the droplet interface and a reservoir fluid surrounding the droplet in the room temperature without any cooling. Condensation on the droplet leads to spatial variation of solute concentration inside the droplet causing buoyancy driven Rayleigh convection. Fluid flow pattern inside a single condensing droplet is symmetric in nature where as the fluid flow pattern for two interacting droplets is asymmetric in nature. The neighboring droplet influences the internal convection through vapor mediated interaction between the two condensing droplets. Here, the condensing droplet senses the neighboring droplet from a distance without any physical contact. The asymmetric nature of the flow pattern is attributed to the modification in the distribution of condensation flux of the droplet in the presence of the neighboring droplet. The flow pattern observed for interacting droplets during condensation is opposite to that of evaporating droplets. The effect of the neighboring droplet on the internal convection of the condensing droplet reduces with increase in separation distance between the droplets.
