Numerical Analysis on the Dropwise Condensation of a Binary Vapor Mixture
Numerical Analysis on the Dropwise Condensation of a Binary Vapor Mixture
复制标题
DOI：
10.1115/imece2001/htd-24130
复制
发表时间：
2001-11
期刊：
影响因子：
--
通讯作者：
H. Akiyama;T. Nagasaki;Yutaka Ito
中科院分区：
文献类型：
--
作者：
H. Akiyama;T. Nagasaki;Yutaka Ito
对水和乙醇混合蒸汽在水平壁面上的凝结进行了二维数值模拟。该分析解决了不稳定的流动和传热传质的液体和蒸汽在界面处的相平衡条件，使用有限差分和边界拟合坐标跟踪界面的变形。计算是从一个非常薄的光滑液膜开始的，并且发现当膜厚度达到一定值时会发生不稳定性，从而导致形成相对较小的液滴。随着液滴的增长，它们合并成更大的液滴。在液滴之间存在极薄的液膜，并且表面张力梯度维持液滴。随着壁面过冷度的增加，由于Marangoni效应的增强，最大液滴变大。
A numerical simulation was performed on the condensation of water and ethanol vapor mixture on a horizontal wall in a plane two-dimensional field. The analysis solves unsteady flow and heat-and-mass transfer both for liquid and vapor with the phase equilibrium condition at the interface, using FDM and boundary-fitted coordinates to track the deformation of interface. The calculation was started from a very thin smooth liquid film, and it was found that instability occurs when the film thickness reaches a certain value resulting in the formation of relatively small droplets. With the growth of the droplets, they coalesce into larger ones. Between the droplets an extremely thin liquid film exists, and the surface tension gradient sustains the droplets. With the increase of the wall subcooling the maximum droplet becomes large due to the increase of the Marangoni effect.