A hybrid sectional-moment model for coagulation and phase segregation in binary liquid nanodroplets

摘要

We describe a new formulation of the aerosol general dynamic equation (GDE) that incorporates the phase segregation in a binary aerosol. The model assumes that complete phase segregation is the thermodynamically favored state, that no thermodynamic activation energy exists, and that the segregation process is kinetically controlled. We develop a GDE formulation that involves the solution of a distribution function N_(n,σ)(V), where N_(n,σ)(V) is the number density of aerosols with volume V and n phase domains (which we might think of as enclosures) with an enclosure size distribution characterized by σ. The model improves our earlier efforts (Struchtrup H., M. Luskin M. Zachariah, 2001. J. Aerosol Sci. 15(3) which did not account for the enclosure size distribution. The description of the enclosures is based on a moment approach relying on a log-normal distribution (Park S., K. Lee, E. Otto H. Fissan, 1999. J. Aerosol Sci. 30, 3-16). As with our earlier model, we obtain an increase of the mean number of enclosures per droplet in time, in disagreement to experimental results. The reasons for the disagreement are discussed.