Theory of convective droplet vaporization with unsteady heat transfer in the circulating liquid phase

Abstract The problem of liquid droplet vaporization in a hot convective gaseous environment is analyzed. A new gas-phase viscous, thermal and species concentration boundary layer analysis is developed using an integral approach. The gas-phase analysis is coupled with a modified form of a previous liquid-phase analysis for the internal motion and heat transfer [S. Prakash and W. A. Sirignano, Int. J. Heat Mass Transfer21, 885–895 (1978)]. The coupled problem is solved for three hydrocarbon fuels (n-hexane, n-decane, and n-hexadecane). The results show that the droplet vaporization is unsteady, and that the temperature distribution within the droplet is nonuniform for a significant part of the droplet lifetime. Some of the results are compared with the already existing correlations after correcting them for the heat flux into the liquid phase.