Abstract:Aviation kerosene is a typical endothermic hydrocarbon fuel, and its pyrolysis gas absorbs heat before entering combustion chamber, which plays an important role in the heat protection of high-speed aircraft. Auto-ignition delay time of hydrocarbon fuel and its pyrolysis gas is one of main parameters for ramjet design, and is important data to validate the combustion reaction mechanism. In this work, the reflected shock wave was used to ignite fuels. Aviation kerosene and its pyrolysis gas in a chemical shock wave tube was studied. Ignition delay time was defined as the time interval between the arrival of reflected wave indicated by the jump of pressure signal and the onset of CH* emission signal. Auto-ignition delay times of RP-3kerosene,pyrolysis gas, hydrogen, methane, ethylene and ethane were measured in the temperature range of 900-1820 K, at pressure of 1.01×105 Pa and equivalence ratio of 1.0. Experimental results demonstrate that ignition delay time decreases with the increase of temperature. In the same condition, ignition delay time of methane is the longest and that of hydrogen is the shortest, and the ignition delay of pyrolysis gas is slightly longer than that of aviation kerosene. The activation energy of pyrolysis gas is very close to that of aviation kerosene, around 180 kJ·mol-1.The lowest ignition activation energy of all single component is hydrogen, which is 127.8 kJ·mol-1. The experimental results were compared with the simulation results of combustion kinetic mechanism, which can predict the influence of temperature on ignition delay time. Furthermore, sensitivity analysis of the mechanism was carried out, and the main elementary reactions affecting fuel ignition were obtained.