Chemical Kinetic Model of a Multicomponent Gasoline Surrogate with Cross Reactions

A kinetic
mechanism for a multicomponent gasoline surrogate consisting of isooctane, n-heptane, toluene, and 1-hexene is developed, including
types of cross reactions. The mechanism comprises 1392 species and
6019 reactions. Validation results show good agreement with experimental
observations for pure components and their various mixtures. Moreover,
the multicomponent surrogate and a toluene reference fuel (TRF) surrogate
are validated for a research gasoline fuel using the present model.
The multicomponent surrogate perfomed better in predicting experimental
data compared to the TRF surrogate because of the addition of 1-hexene.
Effects of cross reactions on the ignition delays are discussed. It
is found that three types of cross reactions, namely, reactions between
pure components, reactions between pure components and alkylperoxy
radicals, and reactions between pure components and benzylperoxy radicals,
take effect for the acceleration of ignition delays in a shock tube
and a homogeneous charge compression ignition engine. Accelerate effect
is more pronounced at high-pressure, low-temperature, and fuel-rich
conditions. The model with cross reactions between pure components
and alkylperoxy radicals ignites the earliest, and the model with
reactions between pure components ignites the latest. Cross reactions
between decomposition intermediate species (ethylene, propene, isobutene,
phenyl, and benzaldehyde) have no influence on ignition delay times.