Water droplet non-equilibrium interaction with heated atmosphere - Part II

The paper describes the results of investigation for non-equilibrium effects in fluid droplet / flame interaction resulting in rapid droplet evaporation. The obtained solutions made it possible to compare the results with that provided by the existing equilibrium models and to determine the applicability limits for the existing equilibrium models. The dimensionless criterion was developed characterizing the deviation of small liquid droplet evaporation process from the equilibrium, which permits to determine applicability limits for equilibrium models. Investigating the behavior of individual droplets in a heated air flow allowed distinguishing two scenarios for droplet heating and evaporation. Small droplets undergo successively heating, then cooling due to heat losses for evaporation, and then rapid heating till the end of their life time. Larger droplets could directly be heated up to a critical temperature and then evaporate rapidly. Atomization of droplets interferes the heating and evaporation scenario.