Study of Boiling Heat Transfer on Heterogeneous Wetting Surface With MD Simulation

Abstract

\n Wettability has been proved as an important issue to the thermal transport at solid-liquid interface at different scales, however, its enhancement mechanism has not been clearly understood till now. In this study, the nucleate boiling behavior of argon fluid on heterogeneous wetting surfaces were examined with the non-equilibrium molecular dynamics (MD) method, the ring-patterned and stripe-patterned schemes were designed and analyzed, respectively. By comparing the boiling inception time and evaporation rate of liquid argon atoms, it is found that the ring-patterned surface shows an advantage in the nucleate boiling heat transfer compared with the stripe-patterned one. The differences in heat transfer characteristics for different surfaces can be explained through the qualitative analysis of fluid density distribution and solid-fluid interaction energy. Furthermore, the boiling phenomena on ring-patterned surfaces with alternated hydrophilic and hydrophobic intervals were simulated to study the influence of area fraction of hydrophilic region on the heat transfer performance. It is observed that bubble nucleus firstly appears over the hydrophobic region of the substrate. The substrate with more hydrophilic area will have a better heat transfer performance. It is also demonstrated that there is an optimal area fraction, which can make the evaporation rate of fluid reach the highest value. The findings in this work can contribute to the design and fabrication of nanocoating surface to enhance its heat transfer performance under high heat flux condition.