Detailed modeling of an isolated, ethanol droplet combustion under microgravity conditions
Simulations of ethanol droplet combustion in microgravity have been conducted using a transient, finite-element, reactive flow model that includes a detailed description of gas-phase chemical kinetics and transport as well as non-luminous radiation. The results of the simulations are compared with a wide range of experimental data available in the literature. The experimental targets included ground-based, suspended droplet experiments, drop-tower experiments, and space-based experiments from the Fiber-Supported Droplet Combustion-2 project. The presented model is shown to reproduce closely nearly all aspects of ethanol droplet burning phenomena, such as droplet burning history, average burning rates, radiative extinction behavior, and kinetics of water accumulation in the liquid phase. Both the experimental and computational results reported in the present study suggest that for ethanol droplets burning in air at 1 atm, the radiative extinction diameter has a value of ∼4 mm.