This model overcomes a deficiency of a prior statistical model.

An improved statistical model has been developed to describe the chemical composition of an evaporating multicomponent- liquid drop and of the mixture of gases surrounding the drop. The model is intended for use in computational simulations of the evaporation and combustion of sprayed liquid fuels, which are typically mixtures of as many as hundreds of different hydrocarbon compounds. Since an exact model providing a detailed account of all of the compounds would be computationally intractable, the present statistical model is an approximation designed to afford results that are accurate enough to contribute to understanding of the simulated physical and chemical phenomena, without imposing an unduly large computational burden.

Double-Γ-PDF and Discrete-Model-PDF values were computed for a drop of diesel fuel evaporating at a gas temperature of 600 K. The results shown here are for the time at which a drop has evaporated to one-fifth of its initial mass.

It is further assumed that the simulated phenomena occur at atmospheric pressure, where solubility of the carrier gas into the liquid is negligible, and that the far field conditions are quiescent. The model includes the applicable equations for the conservation of mass, species, and energy.