A two-zone control oriented SI-HCCI hybrid combustion model for the HIL engine simulation

To make HCCI (Homogeneous Charge Compression Ignition) combustion feasible in a SI (Spark Ignition) engine, it is necessary to have the smooth mode transition between SI and HCCI combustions. The SI-HCCI hybrid combustion studied in this paper describes the combustion mode that starts with SI and ends with HCCI combustions. The main motivation of studying the hybrid combustion mode is that the percentage of the HCCI combustion is a good indicator for combustion mode transition control when the hybrid combustion mode is used during the transition. This paper presents a control oriented model for the SI-HCCI hybrid combustion mode, where the SI combustion phase is modeled under a two-zone assumption and the HCCI combustion phase under a one-zone one. Note that SI and HCCI combustions are special cases in this model. The developed model is capable of simulating the entire engine operating range, and it was validated in a HIL (Hardware-In-the-Loop) simulation environment. The simulation results were compared with those of the corresponding GT-Power model, and good correlations were found for both SI and HCCI combustions.