Revised HyChem modeling combustion chemistry of air-breathing high-energy density jet fuel: JP-10

The recently-proposed HyChem (Hybrid Chemistry) approach showed great success for modeling the combustion chemistry of liquid jet fuels involving non-oxygenated intermediate products in the fuel decomposition submodel; yet, oxygenated intermediates and their role have not been examined. On one hand, very scarce oxygenates were quantified, on the other hand, deviations were observed from the current HyChem modeling scheme for these species. The objective of the present study, using an air-breathing high-energy density, low-reactivity jet fuel JP-10 as the example, was seeking to revise the HyChem modeling scheme by jointly examining the pyrolysis and oxidation experiment data, to unveil the impact of critical oxygenated intermediates on modeling combustion chemistry. Firstly, the reaction intermediates were re-evaluated based on recent experimental measurements and theoretical calculations. Secondly, the fuel decomposition submodel was revised to include an oxidation reaction step, so as to extend this novel approach to modeling combustion chemistry of low-reactivity fuel systems. Thirdly, speciation data of pyrolysis and oxidation experiments were proposed to sequentially constrain the lumped reactions of the fuel submodel, which provided a stringent test for the HyChem approach. Lastly, the revised HyChem model was validated by speciation data that was not used for the model development, as well as the global combustion properties, including ignition delay time and laminar flame speed. Improved predictions were achieved, especially for the oxygenated intermediates, e.g., carbon monoxide and aldehydes, which showed a notable impact on the predictions of the global combustion properties.