A shock tube study of jet fuel pyrolysis and ignition at elevated pressures and temperatures

The development of compact HyChem hybrid models for jet fuels requires datasets of pyrolysis product yields to constrain the model and of 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 different jet fuels diluted in air or argon over a temperature range of 1000–1400 K, a pressure range of 12–40 atm, and equivalence ratios of 0.5–1. 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 in three ways: by monitoring fuel removal with laser absorption, by sidewall pressure, and by OH∗ emission. Particular care was taken in mixture preparation and efficient transfer of the gaseous fuel mixture to the shock tube. The current HyChem model by Wang et al. shows good agreement with these data.