Bubble dynamics and heat transfer for pool boiling on hydrophilic, superhydrophobic and biphilic surfaces

Abstract

This paper proposes a detailed analysis of bubble dynamics to describe pool boiling heat transfer in extreme wetting scenarios (superhydrophobic vs hydrophilic). A mechanistic approach, based on extensive post-processing allows quantifying the relative advantage of the superhydrophobic surfaces to endorse the onset of boiling at very low superheats (1-2K) vs their worse heat transfer performance associated to the swift formation of an insulating vapour film. Based on this analysis, a simple biphilic surface is created. The results suggest that for high heat fluxes, bubble dynamics is dominated by the emission of very small bubbles, which seems to affect the interaction mechanisms, precluding the emission of the large bubbles from the surface, thus compromising the good performance of the biphilic surfaces.