Detailed chemical kinetic study of the effect of molecular structure on autoignition of fuel-air mixtures

Kinetic model is used to simulate the ignition of n-butane, isobutane, and n-pentane in air. Computed results are compared with data from shock tube experiments for the two n-alkanes, with very good agreement obtained. Model calculations under conditions of pressure and temperature encountered in internal combustion engines are reported. The influences of fuel molecular size and structure on autoignition rates are discussed in detail in terms of the site-specific H atom abstraction rates and subsequent fragmentation patterns of the alkyl radicals for each of the fuels considered.