A chemical kinetics model of iso-octane oxidation for HCCI engines

The necessity of developing a practical iso-octane mechanism for homogeneous charge compression ignition (HCCI) engines is presented after various different experiments and currently available mechanisms for iso-octane oxidation being reviewed and the performance of these mechanisms applied to experiments relevant to HCCI engines being analyzed. A skeletal mechanism including 38 species and 69 reactions is developed, which could predict satisfactorily ignition timing, burn rate and the emissions of HC, CO and NOx for HCCI multi-dimensional modeling. Comparisons with various experiment data including shock tube, rapid compression machine, jet stirred reactor and HCCI engine indicate good performance of this mechanism over wide ranges of temperature, pressure and equivalence ratio, especially at high pressure and lean equivalence ratio conditions. By applying the skeletal mechanism to a single-zone model of HCCI engine, we found out that the results were substantially identical with those from the detailed mechanism developed by Curran et al. but the computing time was reduced greatly.