Lattice Boltzmann simulation of bubble evolution at boiling on surfaces with different wettability

Abstract

The hybrid Lattice Boltzmann method is adopted for a detailed study of surface wettability effects on evolution of vapor bubbles and temperature field of heat exchange surface at boiling. The simulation results show that the bubble departure diameter increases with an increase of static contact angle, and its value normalized by the capillary length approaches 3 for superlyophobic surface. In the range of contact angles of 110° – 129° the size of the dry area bounded by triple contact line greatly increases compared to the bubble departure diameter. At contact angles θ ⩾ 153° the dry area does not shrink even at the bubble departure stage and the typical film boiling regime is observed. It has been shown that the deterioration of wettability affects the evolution of the temperature field beneath the bubble, which leads to a significant change in the local heat transfer rate.

Recent Advances of Surface Wettability Effect on Flow Boiling Heat Transfer Performance

“…Generally speaking, the weak wetting surface have larger effective nucleation hole size range and higher nucleation center density to improve boiling heat transfer performance under low heat flux. Fedoseev et al (2020) also showed that enhancement of heat transfer observed on weak wetting boiling surface because to the increasing nucleation site density and the decreasing boiling onset temperature by Lattice Boltzmann simulation. Meanwhile, they also analyzed the dry areas on the weak wetting surface.…”