Dynamics of Growth and Breakup of an Evaporating Pendant Drop

Abstract

The growth and pinch-off dynamics of an evaporating pendant drop have been studied through direct numerical simulations. A coupled level-set and volume-of-fluid method is utilized to perform the simulations in an axisymmetric coordinate system. The dynamics of an evaporating pendant drop depends on the combined effects of buoyancy, capillary force, and the evaporation rate at the interface. The volumetric growth-rate of the drop decreases with the increase in degree of superheat of the surrounding medium, thereby enhances the pinch-off time. However, the departure diameter decreases with an increase in superheat. Limiting length and neck radius are not significantly affected due to the variation in degree of superheat. The heat transfer characteristics at different stages during the growth of a pendant drop have been analyzed for various values of superheat.