The controlled auto-ignition (CAI), also known as gasoline homogeneous charge compression ignition (HCCI), improves dramatically the efficiency of a gasoline engine without penalties in emissions. Although CAI produces negligible NO{sub}x, and a simple three-way catalyst suffices, it depends strongly on judiciously operating the engine dynamically. Gasoline direct injection (GDI), variable valve actuation (VVA), exhaust gas recirculation (EGR), turbo-charging (TC) and advanced controls based on combustion state sensing are key factors to enable the dynamic operation of the CAI combustion process. Test bench investigation on a single-cylinder research engine were undertaken to investigate these actuation strategies, using thermodynamic analysis and thermo-kinetic simulation, in defined operating points to show the effects that influence the self-ignition and combustion process of CAI.
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