Development of a Reduced Chemical Kinetic Model for Prediction of Preignition Reactivity and Autoignition of Primary Reference Fuels

A reduced chemical kinetic model has been developed for the prediction of major oxidation behavior of primary reference fuels (PRF's) in a motored engine, including ignition delay, preignition heat release, fuel consumption, CO formation and production of other species classes. This model consists of 29 reactions with 20 active species and was tuned to be applicable for the neat PRF's, 87 PRF and 63 PRF, and at various engine conditions. At the motored engine condition where detailed species data were generated, the model reproduces the ignition delay and the preignition heat release quite well (to within 15%). Fuel consumption and CO formation predictions differed from experiments by at most 25% for all of the four fuels. Predictions for other species classes generally agreed with experiments. As inlet temperature was varied, the experimentally observed negative temperature coefficient (NTC) behavior of iso-octane and 87 PRF was reproduced by the model. In addition, the lower reactivity of 87 PRF at a lower compression ratio was also predicted, indicating that the model can account for the effects of pressure or charge density.