Engine Modeling of HCCI Transient Operations 2005-01-0158

Control strategies for HCCI (Homogeneous Charge Compression Ignition) operation in 4-cylinder, 4-stroke engines were investigated using a simple engine model, which is composed of intake, combustion and gas exchange sub-models. The model can determine, cycle-by-cycle, cylinder-by-cylinder, control variables, such as air mass, residual gas mass, temperature at the beginning of the compression stroke, combustion start timing in a wide range of exhaust valve closing timings and clearance volumes. The calculation results were compared with experimental results which have been presented previously. The model can simulate combustion fluctuation during a operation mode change from spark ignition to HCCI with variable exhaust valve closing timings and clearance volumes. Also, the model can predict the control variables during transient in the compression ratio by clearance volume change and during low temperature combustion reaction, to develop control strategies of transient operations.