Internal boiling and superheating in vaporizing multicomponent droplets

Abstract

The vaporization and combustion of a miscible multicomponent droplet in a quiescent atmosphere is analyzed by assuming transient‐diffusive transport within the droplet, quasi steady diffusive‐convective transport in the gas phase, and ideal solution behavior for the mixture. Results on the vaporization of a binary droplet show that owing to the significant liquid phase diffusional resistance, the vaporization process approximately consists of an initial transient regime, an intermediate, diffusion limited, almost quasi steady regime, and a final volatility limited regime. It is further demonstrated that the entrapment of the volatile components within the rapidly heated droplet interior may lead to the initiation of either homogeneous or heterogeneous nucleation, which can result in the fragmentation of the parent droplet with the internal pressure buildup.

Development of an Experimental Database and Kinetic Models for Surrogate Diesel Fuels

“…However, fundamental droplet vaporization studies show [43][44][45] that the excessively small liquid-phase mass diffusion can limit the rates with which species can be transported to the surface and vaporized. In the limit of vanishing mass diffusivity the vaporization process would assume a so-called onionskin mode, in which the fractional vaporization rate of the individual species is simply its mass fraction in the liquid [46].…”

Thermal Properties and Burning Efficiencies of Crude Oils and Refined Fuel Oil

“…For fresh Grane however, there is no significant amount of water present in the fuel and boilover cannot be caused by superheating of a water layer. This suggests that boilovers are 2017 INTERNATIONAL OIL SPILL CONFERENCE 12 similar to microexplosions observed during the combustion of multicomponent droplets with a large difference in the boiling point between its components (Law, 1978;Wang et al, 1984;Ikegami et al, 2003). Rather than water, it would be light hydrocarbons trapped in the viscous fuel slick that superheat and result in the boilover.…”

Secondary atomization of single coal-water fuel droplets

“…4) Thermal properties were constant and evaluated at 100 OC. 5) Fluctuations in droplet size were did not significantly affect evaporation or ' energy absorption. This final assumption was tested for two droplets, one that received 2930 WIcm2 and one that received 9350 WIcm2.…”