Understanding the mechanisms of pyrolysis endothermic and oxidative exothermic reactions is vital in developing endothermic hydrocarbon fuel in reducing engine surface temperature of hypersonic vehicle.In this paper,the reaction mechanisms of endothermic and exothermic processes were revealed for the widely used endothermic fuel of JP-10 by ReaxFF molecular dynamics simulations(ReaxFF MD).The heat-up simulation results show that the transition point from endothermic to exothermic for the total reaction heat effect of JP-10 oxidation system is around 2 600 K.The absorbed heat of the ring-opening reactions in the endothermic stage accounts for about 64％of the total heat absorption.The stepwise reactions of H free radicals and O2 into HO2 and HO free radicals,and HO2 and HO into H2O will release a large amount of heat,accounting for about 54％of the total heat release in the oxidation stage.This work demonstrates that reaction energy analysis of ReaxFF MD simulations is potentially a new approach for identifying important reaction pathways and understanding the effects of fuel molecular structures on fuel endothermic capacity and fuel pyrolyzate composition on fuel oxidative exothermic capacity.
维普
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