Interaction between multiple bubbles in microchannel flow boiling and the effects on heat transfer

Abstract

Flow boiling in microchannels have widely been studied in order to design more efficient cooling systems with numerical simulations forming a crucial part to deal with the areas that cannot be investigated experimentally. Previously published research largely focussed on the behaviour of a single bubble. Here, we focus on the behaviour of multiple bubbles. In this study, the influence of the distance between the bubbles (liquid slug length) is investigated in both an axisymmetric and a planar domain for two and three bubbles present. In this regard, an interface-tracking adaptive mesh refinement model was implemented to improve simulation time. Results show that the heat transfer was improved with sequential bubbles, and a 50% increase in heat transfer coefficient was observed for the cases investigated with three bubbles present. The heat transfer also improved the closer the bubbles were together.