Progress is reported in a project concerned with simple modeling and laboratory experiments to elucidate the mechanisms whereby trace amounts of unburned hydrocarbons may persist after the combustion event in Otto-cycle-type internal-combustion-engine cylinders, and the fate of these residual hydrocarbons during the power-stroke and exhaust-event portions of the cycle. The motivation for the research is that a highly fuel-lean fast-burn design for the spark-ignition homogeneous-charge, four-stroke engine may permit exceptionally fuel-efficient operation of this highly driveable, relatively well-understood automotive engine. Work during this period concentrated on the mathematical modelling of wall quenching and turbulent flame propagation. (LCL).

The optimization of combustion in reciprocating engines necessitates an in-depth understanding of the underlying processes as well as accurate and comprehensive physical models. In this respect, the current knowledge on the last stage of combustion in which the flame interacts with the combustion chamber walls is limited. Hence, the objective of this book is to improve the understanding of flame-wall interaction and its modelling. Using a comprehensive analysis of the existing literature on flame-wall interactions as a starting point, the quenching process in a direct-injection spark-ignition engine is investigated via a combination of highly resolved wall heat flux measurements and extensive numerical simulations in order to gain insight into the underlying physical processes. Building on the results, a consistent modelling approach is systematically derived based on the physics of flame quenching and post-flame oxidation. The resulting flame-wall interaction model is based on the G-equation combustion model and incorporates the effects of flame quenching and near-wall turbulence. Finally, the model is applied to simulate combustion in a turbulent channel flow as well as in spark-ignition engines. The results are highlighting the importance of flame-wall interactions for premixed combustion processes in engines and their prediction via simulation.

Emission and fuel economy regulations and standards are compelling manufacturers to build ultra-low emission vehicles. As a result, engineers must develop spark-ignition engines with integrated emission control systems that use reformulated low-sulfur fuel. Emission Control and Fuel Economy for Port and Direct Injected SI Engines is a collection of SAE technical papers that covers the fundamentals of gasoline direct injection (DI) engine emissions and fuel economy, design variable effects on HC emissions, and advanced emission control technology and modeling approaches. All papers contained in this book were selected by an accomplished expert as the best in the field; reprinted in their entirety, they present a pathway to integrated emission control systems that meet 2004-2009 EPA standards for light-duty vehicles.