Numerical study on the effects of inertia and wettability on subcooled flow boiling in microchannels

This study aims to explore the effects of wettability and inertia on heat transfer during flow boiling in a microchannel. For this purpose, we numerically characterized a nucleated bubble and its heat transfer rate on heated surfaces with different wettabilities under specific mass fluxes. The numerical results were consistent with those obtained in previous experimental studies. Under low mass fluxes (20–100 kg/m²s), the critical heat flux (CHF) was higher in the hydrophilic channel than in the hydrophobic channel. However, under high mass fluxes (200–500 kg/m²s), this trend reversed. Increasing the mass flow rate also delayed the incipient boiling. This behavior is strongly related to the inertia force and surface tension. In conclusion, the hydrophilic and hydrophobic channels enhanced the CHF at low and high mass fluxes, respectively.