Asymptotic evaporation of spherical drops

Abstract

The equations governing spherically symmetric vaporization of liquid drops in an infinite hot environment are solved for conditions typical of drop shrinkage in the asymptotic stage which is controlled by the transport of heat and mass. The Jakob number for drop evaporation is derived. The vaporization constant is determined whose magnitude is confined within the upper and lower limits. The lower limit coincides with the previously reported quasi-steady approximation, while the upper limit is a constant multiple of the lower limiting value. The effects of radial convection resulting from unequal phase densities, high system pressure, and vapor diffusion in the environment are established and the regions of applicability of the quasi-steady approximation are determined.