Bubble nucleation, growth, and departure: A new, dynamic understanding

The bubble nucleation, growth, and departure cycle is a fundamental aspect of nucleate pool boiling. While much research on this subject has been performed in the previous century, new correlations and models have not been developed in light of important results in simulations and experiments in recent decades. In this work, we provide an updated understanding of nucleation, growth, and departure with analytical models that are validated by recent work. We found that nucleation at incipience is correlated to departure size, suggesting that the momentum-induced bubble snap-off at departure may be responsible for the size of trapped vapors in cavities. We also developed a bubble growth model that takes into account a thermal boundary layer whereas previous works typically considered a uniform superheating. In addition, we developed a bubble departure description, wherein the velocity boundary layer is responsible for closing the base of the bubble. Finally, we provide a methodology to calculate bubble growth and departure for contact angle changing with time, which is relevant in studying surfactant-enhanced boiling. (C) 2019 Published by Elsevier Ltd.