Mechanism reduction strategies for multicomponent gasoline surrogate fuels

Skeletal mechanisms for TRF mixtures were generated using DRGEPSA followed by unimportant reaction elimination. A detailed mechanism with 1389 species and 5935 reactions was reduced to different levels of complexity ranging from 386 species and 1591 reactions (lowest error) to 173 species and 689 reactions (highest error). Validation was performed using ignition delay and laminar flame speed calculations, and good agreement with the detailed mechanism was found for the error limits considered. Representative HCCI simulations of normal and low-load operation were also performed using the skeletal mechanisms. All skeletal mechanisms predict ignition to within 4 CA degrees, but only the largest skeletal mechanism to within 1 CA degree. Fuel and CO mole fraction profiles were also compared with good agreement in general, but noticeable error in the exit CO mole fraction for the very lean low-load case.