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The oxidation of surrogate diesel fuels composed of mixtures of three pure hydrocarbons with and without their cetane numbers chemically enhanced using 2-ethylhexyl nitrate (2-EHN) is studied in a variable pressure flow reactor over a temperature range 500 - 900 K, at 12.5 atmospheres and a fixed reaction time of 1.8 sec. Changes in both low temperature, intermediate temperature, and hot ignition chemical kinetic behavior are noted with changes in the fuel cetane number. Differences appear in the product distribution and in heat release generated in the low and intermediate temperature regimes as cetane number is increased. A chemically enhanced cetane fuel shows nearly identical oxidation characteristics to those obtained using pure fuel blends to produce the enhanced cetane value. The decomposition chemistry of 2-EHN was also studied. Pyrolysis data of 10% 2-EHN in n-heptane and toluene are reported.

Homogeneous gas phase kinetic experiments at high pressures and intermediate temperatures are critical for furthering an understanding of the autoignition chemistry of spark ignition engine fuels. In order to perform such experiments, a new variable pressure flow reactor has been developed. This device can be used to study homogeneous gas phase chemical kinetics over the pressure range from 1 to 28 atmospheres and the temperature range from 700 to 1300 K. Initial validation experiments were performed at pressures from 1 to 9 atmospheres using stoichiometric hydrogen and oxygen mixtures. Post-induction chemical kinetic results compare favorably with earlier atmospheric pressure flow reactor data and with numerical results predicted using a recently published comprehensive kinetic CO/H2/O2 mechanism. Near stoichiometric n-butane and oxygen flow reactor experiments were performed at pressures of 3 atm to 8 atm and with initial temperatures from 708 K to 945 K.