Vibration-enhanced condensation heat transfer on superhydrophobic surfaces: An experimental study

Experiments were carried out to investigate the effects of mechanical vibration on water condenser performance on uncoated, superhydrophilic, and superhydrophobic aluminum. It was shown that the superhydrophobic surface increases the condensation rate by 30%. However, vibration under a constant frequency (in the range of 60 Hz–160 Hz), regardless of surface wettability, does not significantly improve the condensation rate as only few drops get resonated and removed at that specific frequency (the drop’s natural frequency depends on the drop size and increases for smaller drops). By applying a cyclic variable frequency with a peak of 132 Hz, shedding events on the superhydrophobic surface increased by 120%, which leads to a 15% increase in condensation. The findings of this study demonstrate that applying vibration with a variable frequency is a simple and cost-effective method for heat transfer enhancement on superhydrophobic surfaces.