Cooling of Freely Falling Liquid Drops with a Shell of an Immiscible Volatile Liquid

Abstract

An augmentation of evaporative cooling of liquid drops falling freely through the atmosphere has been attempted by attaching them with some amount of immiscible volatile liquid. An experimental study was performed for a water/n-pentane system, the water either being pure or containing a small amount of surfactant. The cooling rate was found to be strongly augmented provided the volatile liquid (n-pentane) engulfed almost completely the liquid which was to be cooled (water). The dependences of the cooling rate on the initial drop temperature, volume ratio of the volatile liquid to the other in each drop, air temperature and humidity were examined.