Predictions of Spray Combustion using Conventional Category A Fuels and Exploratory Category C Fuels

Abstract

Aviation currently contributes about 3% of the world’s CO2 emissions, 5% of the global warming, and 35% of the trade. Reducing the emissions and the global warming from aviation is thus essential. Many approaches to achieve this goal are underway, including H2, fuel cells, and batteries, but also by replacing the fossil jet fuel with sustainable jet fuel from non-fossil feedstocks. This involves many challenges, and among them we have the issue of current jet engines being developed for existing fossil jet fuels. To facilitate the change towards sustainable jet fuel, typically having different thermophysical and combustion properties compared to fossil jet fuels, we need to analyze the sensitivity of combustion to other fuels, having a wider range of thermophysical specifications. Here, we examine combustion of n-heptane, n-dodecane, Jet A, and two test fuels, C1 and C5 in three different combustors. The first and second cases are axisymmetric and rectilinear pre-vaporized premixed bluff-body stabilized flames, whereas the third is a single sector helicopter combustor for liquid fuel. A Finite Rate Chemistry (FRC) Large Eddy Simulation (LES) model is used together with small comprehensive reaction mechanisms of ~300 reactions. Comparison with experimental data is performed for the pre-vaporized combustor configurations. Good agreement is generally observed, and small to marginal differences in combustion behavior is observed between the different fuels.