Single droplet condensation in presence of non-condensable gas by a multi-component multi-phase thermal lattice Boltzmann model

Abstract

A multi-component multi-phase thermal lattice Boltzmann model considering vapor-liquid phase change is developed to study droplet condensation with the presence of non-condensable gas. Some tests, including an isolated droplet evaporation, are conducted to verify the capability of this model in simulating multi-component multi-phase flow with vapor-liquid phase change. After that, single droplet condensation considering non-condensable gas is investigated with different mass fraction of non-condensable component and contact angles. The results show that the influence of the non-condensable gas upon droplet condensation heat transfer is depended on the growth stage and the amount of the non-condensable gas. The mass transfer of vapor and non-condensable component will tend to an equilibrium state with the droplet condensation going. Furthermore, for different contact angles, the dynamic behavior of the contact line plays a critical role in the accumulation effect of the non-condensable component. And the heat transfer of droplet condensation is enhanced by the hydrophilic substrate rather than the hydrophobic substrate as expected, no matter adding the non-condensable component or not. In different conditions, the power law, which fits the droplet radius with time, is used to define the growth rate mathematically.