Advanced combustion for low emissions and high efficiency: a literature review of HCCI combustion concepts
This report reviews an extensive published literature covering a class of advanced combustion concepts for low emissions and high efficiency in internal combustion engines. For diesel engines, these combustion concepts are generically called Homogeneous Charge Compression Ignition (HCCI) and, for gasoline engines,Controlled Auto-Ignition (CAI). The market drivers for exploring these advanced concepts as well as the fundamentals of how they work to enhance performance and reduce engine-out emissions are described using examples from recent literature. Following this introduction, various engine hardware options are reviewed that have been reported to enhance performance and extend the practical speed and load range for advanced combustion modes. Finally, the impact of fuel properties are described for enabling advanced combustion, including the impact of the fuel’s ignition resistance (cetane number), volatility, and fuel composition on engine performance, emissions, and noise.