Growth of spherical droplets by condensation in a quiescent, free molecular environment

Approximate, explicit solutions to the simultaneous heat and mass transfer equations governing the growth of spherical droplets by condensation in a quiescent, supersaturated vapor have been obtained. Free molecule flow conditions are assumed. The temperature and growth rate of droplets under the near thermal equilibrium and near saturation conditions are given as explicit functions of the thermodynamic state of the gaseous phase and the droplet size only. The near saturation, and near equilibrium conditions are satisfied in the practical cases of droplets growing in a pure vapor, and a dilute mixture of a vapor with a noncondensing carrier gas, respectively. The accuracy of the approximation formulas is quite satisfactory; for the typical conditions tested, the maximum error is a few percent.