Abstract: A pre-chamber spark plug that includes a shell. Additionally, the pre-chamber spark plug includes an insulator disposed within the shell. In a particular embodiment, a center electrode has a first portion surrounded by the insulator, and a second portion that extends from the insulator into a pre-chamber. The pre-chamber defined by the shell. In a further embodiment, a ground electrode is attached to the insulator. In particular embodiments, the ground electrode is tubular in shape and includes an inner spark surface ring spaced in surrounding relation to the center electrode to create a spark gap, an outer ring attached to the shell, and a plurality of rounded spokes connecting the inner and outer rings. In a particular embodiment, the ground and center electrodes accommodate attachment of precious metal alloys to increase electrode surface life. In another embodiment the ground electrode and insulator is coaxial to the center electrode.

Abstract: A method of controlling combustion in an internal combustion engine includes measuring parameters of combustion in a cylinder of the engine during a combustion phase of the cylinder, after igniting an air/fuel charge in the cylinder, and calculating the heat release of combustion in the cylinder based on the measured parameters. An auto-ignition event of the air/fuel charge is identified based on the calculated heat release, and, based at least in part on the identified auto-ignition event, at least one of ignition timing in the cylinder for the next combustion phase of the cylinder or an amount of exhaust gas supplied to the cylinder for the next combustion phase of the cylinder is controlled to cause an auto-ignition event of the air/fuel charge in the next combustion phase to shift toward a specified crank angle.

Abstract: A convergent nozzle is in a mixer housing and in a flow path from an air inlet of the mixer to an outlet of the mixer. A convergent-divergent nozzle is in the mixer housing and includes an air-exhaust gas inlet in fluid communication to receive fluid flow from the convergent nozzle and from the interior of the exhaust gas housing. A first nozzle module is configured to be received in the mixer housing and, when received in the mixer housing, define at least a portion of the convergent nozzle or the convergent-divergent nozzle. A second nozzle module is configured to be received in the mixer housing separate from the first nozzle module. The second nozzle module, when received in the mixer housing, is configured to define at least a portion of the convergent or the convergent-divergent nozzle. The second nozzle module has a different flow characteristic than the first nozzle module.

Abstract: An exhaust gas recirculation mixer includes a convergent nozzle in a flow path from an air inlet of the mixer to an outlet of the mixer. The convergent nozzle is oriented converging toward the outlet of the mixer. The nozzle accelerates the flow to high velocity, which is released as a free-jet. The mixer includes an exhaust gas housing having an exhaust gas inlet into an interior of the exhaust gas housing, and a convergent-divergent nozzle having an air-fuel-exhaust gas inlet in fluid communication to receive fluid flow from the convergent nozzle (i.e., the free-jet), the interior of the exhaust gas housing, and a fuel supply into the mixer.

Abstract: A system for controlling an internal combustion engine has an in-cylinder pressure sensor, a crank angle sensor and a controller coupled to receive inputs from the pressure sensor and crank angle sensor. The controller is configured to convert the cylinder pressure input into a combustion metric indicative of the combustion occurring in the measured cylinder and control fuel input and timing into the engine based on the combustion metric. The controller samples the in-cylinder pressure sensor at a high frequency during critical combustion events and at a lower frequency during the non-critical cylinder conditions.

Abstract: Embodiments of a gaseous or dual fuel electronic pressure regulation system (EPRS) for a multipoint fuel injection engine are described herein. Additionally, embodiments of a method for controlling the EPRS are provided. In particular, the EPRS employs an electronic pressure regulator (EPR) capable of accurately determining and controlling the mass flow of gaseous fuel into a fuel rail so as to avoid pressure droop and over- and under-pressurization of the gas admission valves (GAVs). By using the EPRS described above, mass flow is able to be distributed to the downstream manifold or engine cylinders very accurately, and the GAVs are able to be driven simultaneously in a pressure/pulse duration that is optimal for accurate and repeatable operation.

Abstract: An exhaust gas recirculation mixer includes a convergent nozzle in a flow path from an air inlet of the mixer to an outlet of the mixer. The convergent nozzle is oriented converging toward the outlet of the mixer. The nozzle accelerates the flow to high velocity, which is released as a free-jet. The mixer includes an exhaust gas housing having an exhaust gas inlet into an interior of the exhaust gas housing, and a convergent-divergent nozzle having an air-fuel-exhaust gas inlet in fluid communication to receive fluid flow from the convergent nozzle (i.e., the free-jet), the interior of the exhaust gas housing, and a fuel supply into the mixer.

Abstract: An exhaust gas recirculation mixer includes a convergent nozzle in a flow path from an air inlet of the mixer to an outlet of the mixer. The convergent nozzle is oriented converging toward the outlet of the mixer. The nozzle accelerates the flow to high velocity, which is released as a free-jet. The mixer includes an exhaust gas housing having an exhaust gas inlet into an interior of the exhaust gas housing, and a convergent-divergent nozzle having an air-fuel-exhaust gas inlet in fluid communication to receive fluid flow from the convergent nozzle (i.e., the free-jet), the interior of the exhaust gas housing, and a fuel supply into the mixer.

Abstract: An exhaust gas recirculation mixer includes a convergent nozzle in a flow path from an air inlet of the mixer to an outlet of the mixer. The convergent nozzle is oriented converging toward the outlet of the mixer. The nozzle accelerates the flow to high velocity, which is released as a free-jet. The mixer includes an exhaust gas housing having an exhaust gas inlet into an interior of the exhaust gas housing, and a convergent-divergent nozzle having an air-fuel-exhaust gas inlet in fluid communication to receive fluid flow from the convergent nozzle (i.e., the free-jet), the interior of the exhaust gas housing, and a fuel supply into the mixer.

Abstract: An apparatus for monitoring combustion and/or controlling operation of an internal combustion engine includes a processor to receive input from a crank angle sensor and a combustion chamber pressure sensor. The processor receives a first pressure signal during a first volume during the compression phase and a second pressure signal during a second volume corresponding to a portion of expansion phase, where volumes are equal or equivalent. The processor determines an indication of combustion quality of each combustion event, such as poor fire or misfire, based on a comparison of the difference between the first and second pressures to a threshold value associated with each volume.

Abstract: A method of detecting uncontrolled combustion in an internal combustion engine includes sampling in-cylinder pressure sensor configured to measure pressure in a cylinder of the engine and generate a pressure signal, calculating a combustion intensity metric based on the pressure signal, determining a parameter describing how close the engine is to an uncontrolled combustion condition based on the combustion intensity metric, and controlling a substitution rate of a first fuel and a second fuel based on one or more of the parameter and the combustion intensity metric.

Abstract: A system for controlling an internal combustion engine has an in-cylinder pressure sensor, a crank angle sensor and a controller coupled to receive inputs from the pressure sensor and crank angle sensor. The controller is configured to convert the cylinder pressure input into a combustion metric indicative of the combustion occurring in the measured cylinder and control fuel input and timing into the engine based on the combustion metric. The controller samples the in-cylinder pressure sensor at a high frequency during critical combustion events and at a lower frequency during the non-critical cylinder conditions.

Abstract: An engine has an ignition source in a combustion chamber of the engine. An inner housing is provided that includes one or more jet apertures and defines an inner chamber containing the ignition source. An outer housing (or pre-chamber) is provided that includes one or more jet apertures in communication with the main combustion chamber and defines an outer chamber containing the inner housing.

Abstract: A system for controlling an internal combustion engine has an in-cylinder pressure sensor, a crank angle sensor and a controller coupled to receive inputs from the pressure sensor and crank angle sensor. The controller is configured to convert the cylinder pressure input into a combustion metric indicative of the combustion occurring in the measured cylinder and control fuel input and timing into the engine based on the combustion metric. The controller samples the in-cylinder pressure sensor at a high frequency during critical combustion events and at a lower frequency during the non-critical cylinder conditions.

Abstract: An engine has an ignition source in a combustion chamber of the engine. An inner housing is provided that includes one or more jet apertures and defines an inner chamber containing the ignition source. An outer housing (or pre-chamber) is provided that includes one or more jet apertures in communication with the main combustion chamber and defines an outer chamber containing the inner housing.

Abstract: In some aspects, a spark plug includes a spark gap in an enclosure of the spark plug. The spark plug includes a passage in the interior of the enclosure. During operation of the engine, the passage directs flow through the spark gap, primarily away from a combustion chamber end of the enclosure. The passage can direct flow at a velocity of 5 meters/second or greater.

Abstract: In an internal combustion engine, gaseous fuel is injected in a first injection through a pre-combustion chamber into the combustion chamber to mix with air in the combustion chamber. The pre-combustion chamber has a jet aperture in fluid communication between the pre-combustion chamber and the combustion chamber. Mixed gaseous fuel and air is then ingested into the pre-combustion chamber from the combustion chamber and ignited. In a second injection, injecting gaseous fuel into the pre-combustion chamber and expelling, with the second injection, ignited gaseous fuel and air from the pre-combustion chamber through the jet aperture and into the combustion chamber as a flaming jet with a core of gaseous fuel.

Abstract: An injector-igniter assembly includes a passive prechamber and a fuel injector. In an internal combustion engine, fuel is directly injected into a combustion chamber to mix with air in the combustion chamber. Embodiments enable filing the prechamber at different air-fuel-ratio than the main chamber without directly filling the prechamber with fuel. The prechamber has jet apertures in fluid communication with the combustion chamber. In operation, fuel is injected directly into the combustion chamber though nozzles to form a cloud adjacent to openings into the prechamber. Subsequently, mixed fuel and air is ingested into the prechamber from the combustion chamber and ignited. The degree of mixing prior to ingestion into the prechamber can be controlled using different nozzles configurations. Ignited gaseous fuel and air is expelled from the prechamber through the jet apertures and into the combustion chamber as a flaming jet with a core of gaseous fuel.

Abstract: An engine has an ignition source in a combustion chamber of the engine. An inner housing is provided that includes one or more jet apertures and defines an inner chamber containing the ignition source. An outer housing (or pre-chamber) is provided that includes one or more jet apertures in communication with the main combustion chamber and defines an outer chamber containing the inner housing.

Abstract: A system for igniting a mixture in an internal combustion engine includes an elongate plug body generally residing around a center longitudinal axis and adapted to couple to the internal combustion engine. The system also includes a first ignition body residing about an end of the plug body and a second ignition body adjacent the first ignition body to define a flame kernel initiation gap between the second ignition body and the first ignition body. The system also includes a transversely extending cap at the end of the plug body that is longitudinally spaced from the plug body by a support comprising a leg that is radially offset from the center longitudinal axis, the support defining a peripheral opening around a perimeter of the cap where a total radially-facing area of the support is less than a total area of the peripheral opening.