On the discrepancies between theoretical and experimental results for microgravity droplet evaporation

Abstract

This study aims to solve the discrepancies between the theoretical and experimental results for droplet evaporation. In the literature, all the experiments for microgravity droplet evaporation have been conducted in a hot furnace with the droplet suspended by a fiber. We propose that the discrepancies result from the fact that current theoretical models ignored the conduction into the droplet through the fiber and the liquid-phase absorption of the radiation from the furnace wall. For verification, we formulate a comprehensive model with the effects of fiber conduction and liquid-phase radiative absorption accounted for. For the droplet size variation and evaporation rate constant, good agreement is found between our calculations and the experimental data of H. Nomura, Y. Ujiie, H.J. Rath, J. Sato, M. Kono [Proceedings of 26th Symposium (Int.) on Combustion, 1996, pp. 1267–1273]. Radiative absorption and fiber conduction enhance the evaporation rate significantly. At a low temperature of 470 K, the discrepancies are mainly due to the additional fiber conduction, while at a high temperature of 750 K, the liquid-phase radiative absorption becomes mainly responsible.