Droplet heating and evaporation: A new approach to the modeling of the processes

Abstract

A new model for mono-component droplet heating/evaporation is developed, tested, and applied to the analysis of in-house experimental data. The new model links the previously developed liquid phase model, using the analytical solution to the heat transfer equation at each time step, and the gas phase model, using the solution to the equations of the conservation of mass, momentum, and energy leading to an explicit expression for the Nusselt number and implicit expression for evaporation rate of the droplet. The latter expressions are used as boundary conditions for the liquid phase model. The new model is verified using a comparison between its predictions of the droplet temperatures and radii for very large liquid thermal conductivity [1000 W/(m K)] and those of the model, using the assumption that the thermal conductivity of liquid is infinitely large. The closeness between the predictions of these models supports the reliability of both. The model is validated using the experimental data obtained at the Heat and Mass Transfer laboratory of Tomsk Polytechnical University with regard to the heating/evaporation of droplets. The deviations between the measured and predicted droplet radii and temperatures in most cases are shown to be within experimental error margins.