Influence of the "Self-Radiation" of Combustion Products on the Intensity of Evaporation of an Inhomogeneous Water Droplet in the Flame

Abstract

The processes of heat transfer during the heating, evaporation, and boiling of an inhomogeneous (with a solid inclusion) droplet of a liquid (water) in a high-temperature (800–1500 K) gas medium have been modeled numerically. The inclusion (carbonaceous particle) in the shape of a disk of height and diameter 2 mm has been considered. The volume of the water enveloping the inclusion ranged within 5–20 μL. It has been shown that the ″self-radiation″ of triatomic gases in combustion products (using commercial alcohol as an example) significantly intensifies (compared to the air heated to the same temperatures) the heating of the inhomogeneous liquid droplet. A comparative analysis of the influence of the temperature of the gas medium and of the thickness in the liquid film enveloping the inclusion on the basic characteristic of the process under study, i.e., the time of existence (complete evaporation) of the droplet, has been made. The reliability of the results of theoretical investigations and the legitimacy of the conclusions drawn have been assessed experimentally.