加热基板上硅油液滴蒸发诱发的Marangoni对流失稳现象实验研究

发布时间：2018-04-25 00:16

本文选题：液滴 + 蒸发　；参考：《工程热物理学报》2017年09期

【摘要】：实验观察了加热基板上0.65cSt硅油液滴蒸发过程Marangoni对流失稳现象及其演变规律,测量了Marangoni对流失稳的临界条件,分析了润湿半径和Ma数对液滴内Marangoni对流稳定性的影响。结果发现:只有当液滴的接触角减小到某一临界值以下时,液滴内才产生Bénard-Marangoni对流涡胞,涡胞呈"花瓣"状,液滴顶点处较尖细,三相接触线附近为圆弧形,涡胞相互挤压处呈直线形。随着蒸发的进行,涡胞变短变粗。涡胞数随润湿半径、Ma数的增大而增多。产生Bénard-Marangoni对流涡胞的临界接触角θ_c随Ma数的增大而增大。液滴边缘处始终为热毛细对流,无Bénard-Marangoni对流涡胞。
[Abstract]:The phenomenon and evolution of Marangoni convection instability in the evaporation process of 0.65cSt silicon oil drop on heated substrate were observed experimentally. The critical conditions of Marangoni convection instability were measured. The effects of wetting radius and Ma number on the convection stability of Marangoni in the droplet were analyzed. The results show that B 茅 nard-Marangoni convective vortex cell is produced in the droplet only when the contact angle of the droplet decreases below a certain critical value, the vortex cell is "petal" shaped, the tip of the droplet is thin, and the three-phase contact line is circular arc. The vortex cells are in a linear shape at each other's squeezing place. As evaporation progresses, the vortices become shorter and thicker. The number of vortexes increases with the increase of wetting radius and Ma number. The critical contact angle 胃 _ c of B 茅 nard-Marangoni convection vortex cell increases with the increase of Ma number. At the edge of the droplet, the hot capillary convection is always present, and there is no B 茅 nard-Marangoni convection vortex cell.
【作者单位】：重庆大学动力工程学院;重庆大学低品位能源利用技术及系统教育部重点实验室;
【基金】：国家自然科学基金项目(No.51676018)
【分类号】：O35

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