  A hybrid thermal lattice Boltzmann phase-change model was performed to
simulate the pool boiling above a smooth horizontal heater. The effects of
homogenous and heterogeneous wettability on entire boiling curves from the
onset of nucleate boiling (ONB) to fully developed film boiling were
investigated comprehensively. Results show that concerning the homogeneous and
hydrophilic heater, increasing the wall wettability results in a high critical
heat flux (CHF) and yields a rightward and upward shift of the boiling curve.
It is also found that decreasing the wettability promotes the occurrence of ONB
at a lower overheat, but it also makes the boiling process move into a film
boiling regime with a lower degree of wall superheat. Regarding the homogeneous
and hydrophobic heater, there are quite lower CHF and shorter transition
boiling regime, whereas the CHF point and film boiling occur at a lower wall
superheat. For the heterogeneous and hydrophilic heater, increasing the
difference of wettability yields a leftward shift of the boiling curve.
Furthermore, the effects of surface wettability and the width between two
hydrophilic-hydrophobic mixed surface on boiling curves were studied, which
indicated that decreasing the wettability of the hydrophobic surface produces
an upward shift of boiling curve and decreasing the width generates a leftward
and upward shift of the nucleate boiling pattern. Moreover, the enhancement of
boiling heat transfer in terms of hydrophilic-hydrophobic mixed surfaces was
also quantitively verified.
