A Chemical Kinetic Model of PRF Oxidation for HCCI Engine II:Structure of a skeletal model

A skeletal chemical kinetic mechanism including 42 species and 71 reactions for the oxidation of primary reference fuels(PRF)was proposed and applied to simulate homogeneous charge compression igni-tion(HCCI)combustion.The ignition delay predicted by the skeletal mechanism was validated with experi-ments.Validated results show good agreements for the PRF0,PRF60,PRF80,PRF90,PRF100 fuels over temperatures in the range of 667,K to 1,350,K.Validation of the present PRF mechanism was also per-formed with experiments from HCCI engines available in the literature,and good agreement was obtained for the PRF70,PRF91.8,PRF100 fuels.Results show that this PRF mechanism gives reliable performance for HCCI combustion predictions.The present PRF mechanism can be applied to multi-dimensional CFD simulations.Sensitivity analysis indicates that for PRF70 and PRF91.8 fuels under HCCI conditions,H-atom abstraction from iso-octane molecule reaction and OH addition to n-heptane molecule have large influ-ence,and CH2O,CH3 are very important intermediate species.