Abstract
The reaction paths were analyzed in order to clarify the relationship between the fuel molecular structure and its ignition characteristics. The differences of molecular structure appear in RO2 Chemistry and Fuel Fragment Chemistry. Almost all hydrocarbons are converted into ketohydroperoxides and fuel fragments, such as aldehyde, ketone, alkene and smaller alkyl radical, during Low Temperature Oxidation (LTO) range. The contents of fuel fragments are mainly controlled by the length of straight chains in the molecule. LTO start is dominated by both fuel size and smaller ketohydroperoxides reactions. And then, LTO ends when the reaction rate of CH2O + OH is faster than Fuel + OH. Finally, H2O2 concentration and temperature at the end of LTO determine the timing of ignition.
