Analytical prediction of the temperature and the lifetime of an evaporating spherical droplet


In this paper, we propose to predict analytically the temperature of an evaporating spherical droplet. To do so, we first review, from data in the literature, the effect of temperature on the physical parameters involved in cooling-induced evaporation, namely the saturating vapor pressure, the diffusion coefficient of vapor in air, the liquid density, the enthalpy of vaporization and the thermal conductivity of air. These data support a series of approximations that allows us to derive an implicit equation for the liquid temperature. We propose a quadratic approximation of the variation of the saturating vapor concentration with temperature to obtain an explicit prediction of the drop temperature. As a result, an analytical prediction of the droplet lifetime including the cooling effect is proposed.

Colloids and Surfaces A