Electrostatic dispersions and evaporation of clusters of drops of high-energy fuel for soot control

Abstract

A model is presented for the electrostatic dispersion of a poly disperse cluster of evaporating drops embedded into an inviscid vortex. Results from this model obtained for dense clusters of drops show that electrostatic dispersion decreases the mass fraction of the evaporating compound as well as the gas density in side the cluster. Since the sooting tendency of a fuel (through coagulation) is an increasing function of the partial density of the fuel vapor, it is inferred that electrostatic charging decreases the sooting tendency. Results indicate that the sooting tendency is a monotonically decreasing function of the charge. By using this model for different fuels, it is shown that the sooting tendency of a fuel is associated with two competing characteristic times: that of drop dispersion and that of drop evaporation. It is also shown that the drop evaporation time is directly related to the latent heat of the fuel, thereby providing a simple way to relate sooting propensity to fuel-specific properties.