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

This study aims to solve the discrepancies between the theoretical and expe rimental results for droplet evaporation. In the literature, all the experi ments for microgravity droplet evaporation have been conducted in a hot fur nace with the droplet suspended by a fiber. We propose that the discrepanci es result from the fact that current theoretical models ignored the conduct ion into the droplet through the fiber and the liquid-phase absorption of t he radiation from the furnace wall. For verification, we formulate a compre hensive model with the effects of fiber conduction and liquid-phase radiati ve absorption accounted for. For the droplet size variation and evaporation rate constant, good agreement is found between our calculations and the ex perimental data of H. Nomura, Y. Ujiie, H.J. Rath, J. Sato, M. Kono [Procee dings of 26th Symposium (Int.) on Combustion, 1996, pp. 1267-1273]. Radiati ve absorption and fiber conduction enhance the evaporation rate significant ly. 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 liqu id-phase radiative absorption becomes mainly responsible. (C) 2001 Elsevier Science Ltd. All rights reserved.