Kinetic Modeling of Knock Properties in Internal Combustion Engines

This work presents a general model for the prediction of octane numbers and knock propensity of different fuels in SI engines. A detailed kinetic scheme of hydrocarbon oxidation is coupled with a two zone, 1-D thermo-fluid dynamic simulation code (GASDYN) [1]. The validation of the kinetic scheme is discussed on the basis of recent experimental measurements. CFR engine simulations for RON and MON evaluation are presented first to demonstrate the capabilities of the coupled model. The model is then used to compare the knock propensity of a gasoline “surrogate” (a pure hydrocarbon mixture) and PRFs in a current commercial engine, resulting in a simulation of “real world” octane number determination, such as Bench Octane Number (BON).

The simulation results agree qualitatively with typical experimental trends. The overall model is a flexible tool for evaluating knock propensity of different gasolines in different automotive engines and, more specifically, the role of fuel components in formulating new high performance gasolines.