Detailed Kinetic Modelling of the Oxidation and Combustion of Large Hydrocarbons Using an Automatic Generation of Mechanisms

A mechanism generator code to automatically generate mechanisms for the oxidation and combustion of large hydrocarbons has been successfully modified in this work. The modification was through: (1) improvement of the existing rules such as cyclic-ether reactions and aldehyde reactions, (2) inclusion of some additional rules to the code, such as ketone reactions, hydroperoxy cyclic-ether formations and additional reactions of alkenes, (3) inclusion of small oxygenates, produced by the code but not included in the handwritten C1-C4 sub-mechanism yet, to the handwritten C1-C4 sub-mechanism. In order to evaluate mechanisms generated by the code simulation of observed results in different experimental environments has been carried out. The simulation of auto-ignition of n-pentane in a rapid-compression machine shows good agreement with experimental results. Experimentally derived and numerically predicted ignition delays of n-heptane/air and n-decane/air mixtures in high-pressure shock tubes in a wide range of temperatures, pressures and equivalence ratios agree very well. Concentration profiles of the main products and intermediates of n-heptane, iso-octane and n-decane oxidation in jet-stirred reactors at a wide range of temperatures and equivalence ratios are generally well reproduced. Sensitivity and reaction flow analyses were performed for shock tube and jetstirred reactor environments, respectively, in an attempt to identify the most important reactions under the relevant conditions of study. In addition, the ignition delay times of different normal alkanes was numerically studied.