Knocking Prediction by Using Zero-Dimensional Engine Cycle Simulation with Chemical Kinetic Model

Abstract

A zero-dimensional engine cycle simulation has been developed by implementing chemical kinetics as the auto-ignition model into the two-zone combustion chamber model. A mixed chemical reaction mechanism of the primary reference fuels is used. Experimental data have been carefully investigated to obtain correlation between calculated auto-ignition of the end-gas and actual knock intensity. The result shows that a combination of time of auto-ignition occurrence and heat release by auto-ignition can explain knock intensity. This correlation has been applied to the simulation so that it can predict knock occurrence including knock intensity. A number of calculations have been done under various engine parameters including compression ratio, intake temperature, octane rating and equivalence ratio. The results show that fair levels of agreements are obtained between calculated trace knock spark advance sensitivity and experimental trends.