The chemistries of aviation fuels are invariably complex due to large
hydrocarbon molecules. There are also large variations for a given fuel type.
Furthermore, flow timescales encountered in high performance propulsion devices
increasingly lead to difficulties associated with kinetically controlled or influenced
phenomena such as flame stability, extinction and re-light. Current indications also
suggest that fuel sources will become significantly more diverse in the future and
may, for example, encompass Fischer-Tropsch and/or bio-derived components. The
combustion properties of such fuels can vary significantly from those in current use
and this work outlines a route towards surrogate fuel mechanisms of sufficient
accuracy and generality to support the development of practical devices.
A reaction class based route to the derivation of detailed chemical kinetic
mechanisms for alkyl-substituted aromatics is outlined and applied to the
cyclopentadiene/indene, benzene/naphthalene, toluene/1-methyl naphthalene
systems. Work has also been extended to the n-propyl benzene system as well.
These reaction classes were applied to model the oxidation of the above fuels with
encouraging results. Important reaction channels during oxidation were identified
and specifically, the methyl groups on aromatic rings have been identified as
important in the context of radical scavenging. Furthermore, 1-methyl naphthalene
may also be used to modulate sooting tendencies in aviation and Diesel surrogates.
Results obtained from chemical kinetic modelling of cyclopentadiene, toluene, npropyl
benzene, naphthalene and 1-methyl naphthalene oxidation in shock tubes,
jet-stirred and plug-flow reactors at various sets of representative stoichiometries
and temperatures are reported.