Combustion models, used in spark-ignition engine modeling, are reviewed. Different approaches for representing the main combustion features are reported. Limitations in simulating such a complex phenomenon as turbulent combustion in engines are highlighted as well.
In order to compare different combustion models, the multidimensional program KIVA-3V has been used. The behavior of an actual spark-ignition engine has been investigated.
In particular, simulation results, using simple chemical kinetics and mixing-controlled models, are compared. The results obtained, compared to measured data, confirm that different combustion models can lead to a satisfactory prediction of engine performances. But, in many cases, these models require experimental data for determining the model characteristic constants. A hybrid combustion model is proposed. It is able to provide a good reproduction of engine combustion process and, in particular, the model seems to be less sensitive to the engine operation. The computation results are compared to the measured data.