Investigation of bubble dynamics and boiling heat transfer characteristics under vertically heating walls via lattice Boltzmann method

Abstract

Boiling heat transfer characteristics greatly depend on bubble dynamics behaviors. Whereas the influence of bubble dynamics on boiling heat transfer mechanism under the vertical heating wall condition is scarce. In this work, lattice Boltzmann (LB) method is implemented to investigate the relationship between bubble dynamics and boiling heat transfer on the vertical heating wall. Bubble nucleation, growth and departure processes under different wettability conditions are systematically studied. The results demonstrate that the vapor phase covering the vertical surface increases at a greater contact angle. The bubble detachment becomes difficult, leading to the reduction of bubble volume. Because of the interaction of buoyancy force and bubble growth under the vertical heating wall, physical properties of the three-phase contact line and bubble dynamics show strong coupling characteristics. In addition, the heat flux on the hydrophilic and hydrophobic surfaces can be enhanced by 98% and reduced by 75% compared to that on the neutral surface.