Non-Isothermal Mass Transfer in Fluid Drops with Internal Circulation

The influence of internal circulation on the heat and mass transfer within dispersed fluid drops in translation was studied numerically using the computational fluid dynamics simulation tool ANSYS FLUENT. The three phases identified for heat/mass transfer are: the initial and final diffusion-dominated phases and a middle convection-dominated phase. Non-isothermal mass transfer simulations using temperature-dependent diffusion coefficients were carried out to investigate the influence of heating and cooling of the drop on the solute transfer. Mass transfer is slower compared to heat transfer and the final diffusion-dominated mass transfer occurs at the final temperature attained by the drop. Mass transfer is faster for drop heating than for drop cooling, as the final diffusion phase is rate controlling and significant solute transfer occurs at the final higher temperature.