Niu Dong, Gao Hongtao, Tang Guihua, Yan Yuying
Institute of Refrigeration & Cryogenics Engineering, Dalian Maritime University, Dalian 116026, P. R. China.
MOE Key Laboratory of Thermo-Fluid Science and Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an 710049, P. R. China.
Langmuir. 2021 Aug 3;37(30):9009-9016. doi: 10.1021/acs.langmuir.1c00961. Epub 2021 Jul 23.
The presence of noncondensable gas (NCG) followed by undesirable heat transfer deterioration cannot be avoided in some situations. In this work, droplet nucleation and growth for the Ar-Ne mixed system are investigated using molecular dynamics simulation. Different droplet state transition modes corresponding to the subcooling degree or NCG content are obtained. The interaction between NCG and a droplet caused by gas enrichment near the solid surface is considered to explain the droplet wetting state during the condensation process. Finally, the disappearance mechanism of the flooding mode on the nanostructured surface under a large amount of NCG is clarified from the nanoscale, which could encourage a clear understanding of the NCG effect on dropwise condensation heat transfer on nanostructured superhydrophobic surfaces.
在某些情况下,不可避免地会出现不凝性气体(NCG),进而导致不良的传热恶化。在这项工作中,使用分子动力学模拟研究了Ar-Ne混合系统中的液滴成核和生长。获得了与过冷度或NCG含量相对应的不同液滴状态转变模式。考虑了固体表面附近气体富集引起的NCG与液滴之间的相互作用,以解释冷凝过程中的液滴润湿状态。最后,从纳米尺度阐明了大量NCG存在下纳米结构表面上淹没模式的消失机制,这有助于清晰理解NCG对纳米结构超疏水表面上滴状冷凝传热的影响。