Numerical Study of Droplet Evaporation

Abstract

Droplet evaporation plays a vital role in various engineering fields such as air/fuel premixing, inkjet printing and many more. The high rate of power dissipation from the integrated circuits and chips of electronic devices creates a need for cooling it to achieve their optimal functionality. The high rate of cooling can be achieved by thin film evaporation of water by phase change as compared to the air cooling methods. Therefore, the study of droplet evaporation is necessary to understand the underlying physics and effects of different parameters on cooling performance. Numerical study of droplet evaporation has been done by using the level set and arbitrary Lagrangian-Eulerian moving mesh method in COMSOL. These methods are used to track the shrinking liquid-gas interface because of phase change. The changes in the surface tension due to temperature gradient caused by the phase change induces Marangoni convection which influences evaporation. Investigation of the transient droplet evaporation is done wherein the radius of the droplet is pinned and the effect of Marangoni convection on the average droplet temperature is studied for the pure diffusion case. The model developed in this study can easily be extended to study contact line dynamics during droplet evaporation.