Observation of Condensation Dynamics on Micro-structures by Environmental SEM

(Effect of Shape, Size and Wettability)

Abstract

Condensation phase change has received increasing attention in the past decades due to its importance implications in applications such as: electricity generation, air conditioning or water desalination, among others. The size, shape and wettability of the micro- and nano-structures present underneath the condensate have been found paramount for the effective design of condensing surfaces with enhanced heat transfer performance. More specifically, in this work we have carried out a systematic study to address the effect of micro-structure shape and wettability on the dynamics and steady state during condensation phase change at the micro-scale by making use of an Environmental Scanning Electron Microscopy. The distinctive condensation behavior when comparing square and cylindrical micro-pillars is then reported for the first time. We conclude on the importance of the micro-structure shape and wettability for the effective design of enhanced heat transfer condensation surfaces.