Characterisation of reaction propagation from auto-ignition.

Finite supplies of fossil fuels and their current dominance in energy production and usage make their efficient usage and the search for viable alternatives of critical importance. A large part of this is the understanding of the combustion of fuels, both existing and novel and of the engines in which they are consumed.
One fundamental parameter that is not sufficiently understood is excitation time, the almost instantaneous heat release period at the end of an ignition delay period. A reduced thermokinetic model is applied to an attempt to simulate excitation without a large comprehensive model. The failure of the model in this task indicates differences in chemistry between excitation and ignition delay periods that are too large for a simple scheme to overcome with a single set of rate parameters.
This work will present a full and fundamental characterisation through the use of two complimentary diagrams, one an existing diagram for the identification of developing detonation, the other for turbulent burning and adapted to this purpose for the first time. The ε/ξ diagram has been developed with additional groups and parameters which aid in identifying regimes which are potentially beneficial and also those that might be damaging. The newly developed U/K diagram additionally allows the application of the ε/ξ diagram in turbulent burning conditions.
The diagrams are able to identify various combustion modes, including bounds between deflagrative and auto-ignitive propagation and operating regimes for specific engines.