浓度边界层中成长汽泡的界面特性

INTERFACIAL BEHAVIOR OF GROWING BUBBLES IN CONCENTRATION BOUNDARY LAYER

对于双组分池内核态沸腾，热边界层中生成的汽泡，同时也处于浓度边界层中．本文建立了边界展中汽泡表面张力模型，对温度和浓度引起的表面张力变化进行分析．结果表明，表面张力从汽泡顶部到底部是递增的，从而形成液体沿界面自上而下的Marangoni流．通过汽泡底部微层相界面方程的求解，探讨了微层变形特征，由此分析汽泡脱离机理．微层变形与文献[1]中指出的接触线的变化从本质上是一致的．

The nucleate pool boiling of binary mixtures is characterized by growing vapor bubblesexisting in a nonuniform concentration field. The vapor bubble interface is subject to bothconcentration gradients and temperature gradients which give rise to interfacial shear. Amodel for surface tension at the interface is developed. The results show that surface tensionincreases from the top of bubble to the bottom for positive binary mixtures, which will resultin Marangoni flow directed from bubble top to bubble bottom. Solutions of microwedgelayer interfacial equations demonstrate that variation of surface tension along microwedgeinterface is beneficial for liquid layer merging each other, and consquently detaching fullygrown bubbles from the heated surface even in microgravity. The present studies extend ourprevious investigations.