Bubble growth characteristics in bi-component liquid: Influence of component concentration and liquid temperature

A thermodynamic model for bubble growth in superheated liquid mixture was developed to investigate the heat transfer and mass diffusion mechanisms. The influence of component concentration and liquid temperature on bubble growth characteristics is the main focus of the present study. In the proposed model, the energy equation and the component diffusion equation for the liquid were coupled with the assumed quadratic temperature and concentration distribution within the liquid boundary layer. The vapor-liquid equilibrium of the binary mixture was estimated by the non-random two-liquid (NRTL) equation. The comparison between the current calculated results with the available experimental data demonstrates the accuracy of the proposed bubble growth model. The results show that the later stage of bubble growth in a binary mixture is primarily controlled by mass diffusion and also influenced by heat transfer. The bubble growth characteristics strongly depend on the mass fraction of the more volatile component and the liquid temperature. Both higher liquid temperature and concentration of the light component are beneficial to enhance the bubble growth. The effect of mass diffusion on bubble growth becomes weaker with increasing liquid temperature and decreasing initial mass fraction of the more volatile component.