Shock tube study of jet fuel pyrolysis and ignition at elevated pressure

The development of a compact HyChem reaction mechanisms for jet fuels requires datasets both for pyrolysis products yields to constrain the model and for kinetic targets to evaluate the model. To this end, we have measured selected species time-histories during fuel pyrolysis using laser absorption, and ignition delay times using multiple methods behind reflected shock waves in a heated shock tube. Measurements were performed for three jet fuels over a temperature range of 1000-1400 K and pressures from 12 to 40 atm, for equivalence ratios of 0.5 to 1 and diluted in nitrogen or argon. Fuel loading was measured using an IR He-Ne laser at 3391 nm; ethylene with a CO₂ gas laser at wavelengths of 10532 nm and 10674 nm; and methane with a tunable diode laser at wavelengths of 3175 nm and 3177 nm. Ignition delay times were measured three ways: by monitoring fuel removal with laser absorption, by sidewall pressure, and by OH* emission. Particular care was taken in this study in mixture preparation and transfer of the gaseous fuel mixture to the shock tube. The current HyChem model shows good agreement with these data.