INTERFACIAL BEHAVIOR OF GROWING BUBBLES IN CONCENTRATION BOUNDARY-LAYER

The vapor bubble interface for nucleate pool boiling of a binary mixtu re subjects to both concentration gradient and temperature gradient, w hich give rise to interfacial shear, and may create Marangoni flow. A proposed microwedge model is adopted to demonstrate that, variation of surface tension along microwedge interface would be beneficial for li quid layer merging each other, and consequently, detaching fully grown bubbles from the heated surface even under microgravity. This is in q uite good agreement with the experimental observations in the literatu re. The model can be further extended to explain pool boiling phenomen a of binary mixtures at high heat fluxes or even CHF under microgravit y. (C) 1998 Elsevier Science Ltd. All rights reserved.