DOI: 10.1615/THMT-18
ISBN Print: 978-1-56700-468-7
ISBN Online: 978-1-56700-467-0
ISSN Print: 2377-2816
Low-temperature flameless combustion of dodecane droplets in microgravity conditions
ABSTRAKT
The physico-mathematical model of droplet combustion coupled with the detailed reaction mechanism (DRM) of n-dodecane (C12H26) oxidation is used to simulate forced ignition and combustion, as well as self-ignition of an n-dodecane droplet in air at normal pressure under microgravity conditions. The choice of n-dodecane is due to the recent American-Russian space experiment CFI (Cool Flame Investigation) at the International Space Station (ISS) using droplets of this hydrocarbon hold in 2017. Calculations show that after the radiative extinction of the hot flame, the droplet can continue evaporating due to exothermic low-temperature oxidation of fuel vapors with multiple flashes of a blue flame at a characteristic temperature of 980-1000 K. A detailed analysis of the calculation results shows that regular temperature jumps arise from the thermal decomposition of hydrogen peroxide, that is reaction branching with the release of hydroxyl radicals.