Numerical study of bubble dynamics on surface with switchable wettability

In this study, bubble dynamics on surface with switchable wettability was investigated to figure out the mechanism of enhanced boiling performance. A hybrid thermal lattice Boltzmann model with an improved forcing scheme was adopted to evaluate the effects of surface wettability on bubble dynamics. First, temperature distribution on heating surface was analyzed, the nonuniform temperature distribution could induce the wettability transition near triple line locally, and influences bubble dynamics. Then, bubble dynamics on bare surfaces and surface with switchable wettability was investigated. Our results show that bubble departure frequency on switchable surface is matched with hydrophobic surface and bubble waiting time is decreased compared to hydrophilic surface. Moreover, more bubble emerged on switchable surface than both hydrophobic and hydrophilic surface with the same heater size. Besides, three phase contact line movement on the switchable heater surface is faster than hydrophobic surface initially. The enhanced boiling performance on surface with switchable wettability reported in previous literature can attribute to the increased quenching heat flux, more nucleation sites and the enhanced disturbance caused by accelerated triple line movement.