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

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. (C) 2019 Elsevier Ltd. All rights reserved.