A method of assisting ignition of a dedicated exhaust gas recirculation (D-EGR) cylinder in a spark-ignited internal combustion engine. The spark igniter has an internal air passage that receives pressurized air and carries the pressurized air down to an exit port in the vicinity of the spark gap of the igniter.

An engine system includes a combustion chamber and an air supplier. The combustion chamber is formed in a cylinder. The air supplier is configured to supply air to a circumferential area of the combustion chamber. The circumferential area is near an inner circumferential surface of the cylinder. The air supplier is configured to supply air to the circumferential area before ignition to gather a rich air-fuel mixture that is present in the combustion chamber to a central area of the combustion chamber such that a stratified body consisting of a layer of the air-fuel mixture in the central area and a layer of the air in the circumferential area is formed.

Embodiments disclosed herein relate to internal combustion engines, combustion systems that include such internal combustion engines, and controls for controlling operation of the combustion engine. The internal combustion engine may include one or more mechanisms for injecting fuel, air, fuel-air mixture, or combinations thereof directly into one or more cylinders, and controls may operate or direct operation of such mechanisms.

Embodiments disclosed herein relate to internal combustion engines, combustion systems that include such internal combustion engines, and controls for controlling operation of the combustion engine. The internal combustion engine may include one or more mechanisms for injecting fuel, air, fuel-air mixture, or combinations thereof directly into one or more cylinders, and controls may operate or direct operation of such mechanisms.

Methods and systems are provided for a ducted fuel injector. In one example, the ducted fuel injector comprises a plurality of passages, with at least one of the passages configured to receive an oxygen poor gas from a reservoir or an adjacent cylinder to decrease a likelihood of pre-ignition in the duct.

An engine system includes a combustion chamber and an air supplier. The combustion chamber is formed in a cylinder. The air supplier is configured to supply air to a circumferential area of the combustion chamber. The circumferential area is near an inner circumferential surface of the cylinder. The air supplier is configured to supply air to the circumferential area before ignition to gather a rich air-fuel mixture that is present in the combustion chamber to a central area of the combustion chamber such that a stratified body consisting of a layer of the air-fuel mixture in the central area and a layer of the air in the circumferential area is formed.

Methods and systems are provided for reducing wall-wetting and improving mixing of air and fuel within a pre-chamber system of an engine. In one example, a method comprises supplying an air flow to the pre-chamber system via an air injector system while a piston associated with a main chamber is undergoing reciprocating motion. In this way, a rotating or swirling flow of fuel exiting a pre-chamber fuel injector of the pre-chamber system may be induced, which may reduce wall-wetting and improve air and fuel mixing, and when fuel is not being injected to the pre-chamber system the air flow may pressurize the pre-chamber system to reduce an amount of residuals from the main chamber to the pre-chamber system.

Methods and systems are provided for a ducted fuel injector. In one example, the ducted fuel injector comprises a plurality of passages, with at least one of the passages configured to receive an oxygen poor gas from a reservoir or an adjacent cylinder to decrease a likelihood of pre-ignition in the duct.

Methods and systems are provided for adjusting multiplexed ignition signals in an engine system based on engine operating conditions, each cylinder of the engine system including a main chamber spark plug and a pre-chamber system. In one example, a method may include multiplexing spark signals to a first spark plug, a second spark plug, a third spark plug, and a fourth spark plug, the first spark plug coupled to a pre-chamber of a first cylinder, the second spark plug coupled to a pre-chamber of a second cylinder, the third spark plug coupled to a main chamber of the first cylinder, and the fourth spark plug coupled to the main chamber of the second cylinder. In this way, one ignition coil may be used to actuate two different spark plugs coupled to separate cylinders.

A method of assisting ignition of a dedicated exhaust gas recirculation (D-EGR) cylinder in a spark-ignited internal combustion engine. The spark igniter has an internal air passage that receives pressurized air and carries the pressurized air down to an exit port in the vicinity of the spark gap of the igniter.