Abstract: Operating an engine includes moving a piston in a combustion chamber between a bottom dead center position and a top dead center position in an engine cycle. A fuel is injected into the combustion chamber through a plurality of sets of nozzle outlets varied set-to-set with respect to outlet size and spray angle. Spray jets of the injected fuel are propagated in an impingement-limiting fuel spray pattern that is based on the set-to-set variation in outlet size and spray angle so as to limit dissipation of heat from combustion of the injected fuel to material of the engine by way of a thermal barrier coating (TBC) upon a surface of the combustion chamber.

Abstract: A combustion control system for a dual fuel engine includes a combustion control unit structured to receive phasing data for combustion of a main charge of gaseous fuel ignited by way of pilot shots of a liquid fuel, output a pilot fueling command based on the phasing data, and output a valve timing command. The combustion control unit is further structured to vary a phasing of combustion of a main charge of a gaseous fuel ignited by pilot shots of a liquid fuel based on an adjustment to at least one of a pilot shot delivery parameter or a valve timing parameter such as intake valve closing timing from a first engine cycle to a second engine cycle. Control of the intake valve timing can be based on a main pilot shot timing error.

Abstract: A combustion control system for a dual fuel engine includes a combustion control unit structured to receive phasing data for combustion of a main charge of gaseous fuel ignited by way of pilot shots of a liquid fuel, output a pilot fueling command based on the phasing data, and output a valve timing command. The combustion control unit is further structured to vary a phasing of combustion of a main charge of a gaseous fuel ignited by pilot shots of a liquid fuel based on an adjustment to at least one of a pilot shot delivery parameter or a valve timing parameter such as intake valve closing timing from a first engine cycle to a second engine cycle. Control of the intake valve timing can be based on a main pilot shot timing error.

Abstract: A method for controlling an air-fuel ratio (AFR) in an engine powered by a gaseous fuel having an unknown composition may comprise receiving an assumed gas species composition for the gaseous fuel, and determining an assumed lower heating value (LHV) for the assumed gas species composition. The method may further comprise determining a perceived lower heating value (LHV) for the gaseous fuel based on a perceived gas mass flow and a gas energy flow for the gaseous fuel, and updating the assumed gas species composition until the assumed LHV and the perceived LHV are aligned. The method may further comprise determining a desired AFR and an airflow necessary to provide the desired AFR using the aligned gas species composition and a desired lambda (?), and adjusting an air system controller of the engine to provide the airflow.

Abstract: A method for controlling an air-fuel ratio (AFR) in an engine powered by a gaseous fuel having an unknown composition may comprise receiving an assumed gas species composition for the gaseous fuel, and determining an assumed lower heating value (LHV) for the assumed gas species composition. The method may further comprise determining a perceived lower heating value (LHV) for the gaseous fuel based on a perceived gas mass flow and a gas energy flow for the gaseous fuel, and updating the assumed gas species composition until the assumed LHV and the perceived LHV are aligned. The method may further comprise determining a desired AFR and an airflow necessary to provide the desired AFR using the aligned gas species composition and a desired lambda (?), and adjusting an air system controller of the engine to provide the airflow.

Abstract: A system associated with an internal combustion engine is disclosed. The system may be configured to inject fuel at a current fuel injection flow rate and to direct exhaust at a current EGR flow rate. A controller may be configured to determine a maximum fuel injection flow rate and a maximum EGR flow rate based on a first and second group of operating parameters, wherein the first and second group may comprise at least common operating parameter including an oxygen-to-fuel ratio limit. Additionally, the controller may set the current fuel injection flow rate to the maximum fuel injection if a fuel injection flow request, associated with a fuel injector, is greater than the maximum fuel injection flow rate and set the current EGR flow rate to the maximum EGR flow rate if an EGR flow request, associated with an EGR valve, is greater than the maximum EGR flow rate.