Abstract: Operating an engine includes moving a piston toward a top-dead-center position in a cylinder, and directly injecting a gaseous hydrogen fuel into the cylinder in an injection path targeting a center cone in a combustion bowl of the piston. The gaseous hydrogen fuel is impinged upon an outer cone surface, and fluids advanced upwardly along a reentrant bowl wall toward a bowl throat opening. Squished fluids are advanced from a squish volume into the reentrant bowl throat, to produce a combined mixing flow of the advanced fluids and the squished fluids around a flow axis extending circumferentially around a piston center axis. Related apparatus is also disclosed.

Abstract: Operating an engine includes moving a piston toward a top-dead-center position in a cylinder, and directly injecting a gaseous hydrogen fuel into the cylinder in an injection path targeting a center cone in a combustion bowl of the piston. The gaseous hydrogen fuel is impinged upon an outer cone surface, and fluids advanced upwardly along a reentrant bowl wall toward a bowl throat opening. Squished fluids are advanced from a squish volume into the reentrant bowl throat, to produce a combined mixing flow of the advanced fluids and the squished fluids around a flow axis extending circumferentially around a piston center axis. Related apparatus is also disclosed.

Abstract: Operating a gaseous fuel engine includes spark-igniting gaseous hydrogen fuel and air, and propagating combustion gases of the spark-ignited mixture outwardly from a spark gap. The propagating combustion gases are impinged upon a cone surface of a piston so as to limit a flame area of the propagating combustion gases. Additional gaseous hydrogen fuel and air is ignited in the combustion cylinder by way of the propagating combustion gases to urge a piston toward a bottom-dead-center position.

Abstract: A fuel injector includes a nozzle assembly having a nozzle case, and a concentric check assembly within the nozzle case. Transfer passages are formed in an outer check of the check assembly, and spray orifices are formed in the nozzle case. A fuel volume is formed between the outer check and an inner check, and the inner check is movable to fluidly connect the transfer passages to the fuel volume. The outer check is rotatable between a first angular orientation and a second angular orientation to fluidly connect separate sets of the transfer passages to separate sets of the spray orifices. Spray ducts are in spray path alignment with at least one of the sets of spray orifices.

Abstract: Operating a gaseous fuel engine includes spark-igniting gaseous hydrogen fuel and air, and propagating combustion gases of the spark-ignited mixture outwardly from a spark gap. The propagating combustion gases are impinged upon a cone surface of a piston so as to limit a flame area of the propagating combustion gases. Additional gaseous hydrogen fuel and air is ignited in the combustion cylinder by way of the propagating combustion gases to urge a piston toward a bottom-dead-center position.

Abstract: An engine system includes an engine housing having a cylinder block and a cylinder head. An intake opening and an exhaust opening and an igniter opening are formed in a fire deck surface of the cylinder head. A plurality of always-open fuel admission ports are fluidly connected to a combustion chamber and arranged in at least one of the cylinder block or the cylinder head. The always-open fuel admission ports convey a gaseous fuel such as a gaseous hydrogen fuel, a gaseous hydrocarbon fuel, or still others, to the combustion chamber.

Abstract: A fuel injector includes an injector housing having a nozzle assembly with a nozzle piece, and a nested check assembly of an outer check and an inner check. Spray orifices are formed in the nozzle piece in a first orifice set equipped with a first spray duct set and a second orifice set equipped with a second spray duct set. The inner check can be opened to spray fuel from the first orifice set and the outer check can be opened to spray fuel from both the first orifice set and the second orifice set. The outer check is non-rotating while the inner check can be permitted to rotate during service. Spray ducts associated with the first orifice set may have a different duct length and duct inside diameter than spray ducts associated with the second orifice set. The first orifice set may include lower-flow spray orifices and the second orifice set may include higher-flow spray orifices. Related methodology is also disclosed.

Abstract: A fuel injector includes an injector housing having a nozzle assembly with a nozzle piece, and a nested check assembly of an outer check and an inner check. Spray orifices are formed in the nozzle piece in a first orifice set equipped with a first spray duct set and a second orifice set equipped with a second spray duct set. The inner check can be opened to spray fuel from the first orifice set and the outer check can be opened to spray fuel from both the first orifice set and the second orifice set. The outer check is non-rotating while the inner check can be permitted to rotate during service. Spray ducts associated with the first orifice set may have a different duct length and duct inside diameter than spray ducts associated with the second orifice set. The first orifice set may include lower-flow spray orifices and the second orifice set may include higher-flow spray orifices. Related methodology is also disclosed.

Abstract: An igniter for a dual fuel engine includes an igniter body having spray outlets formed in a nozzle and arranged in a plurality of outlet sets. The igniter further includes a plurality of outlet checks each movable in the igniter body to open and close the spray outlets in a respective one of the plurality of outlet sets, and spark electrodes mounted to the igniter body and forming a spark gap. The outlet sets vary set-to-set in at least one of spray angle, spray outlet number, or spray outlet size. Related methodology is disclosed.

Abstract: An internal combustion engine system includes an engine housing having a combustion cylinder, and a piston movable within the combustion cylinder to increase a pressure therein to an autoignition threshold for injected fuel. The piston includes a piston crown having a combustion face forming a combustion bowl, and varied in profile to form jet-jet interaction limiters at locations offset from fuel spray jet paths from a fuel injector. The jet-jet interaction limiters include a bowl component and a step component protruding, respectively, within the combustion bowl and a step located transitioning between the combustion bowl and a circumferential rim of the piston. Limiting jet-jet interaction limits soot production in exhaust produced by the engine.

Abstract: A fuel injector includes a nozzle assembly having a nozzle case, and a concentric check assembly within the nozzle case. Transfer passages are formed in an outer check of the check assembly, and spray orifices are formed in the nozzle case. A fuel volume is formed between the outer check and an inner check, and the inner check is movable to fluidly connect the transfer passages to the fuel volume. The outer check is rotatable between a first angular orientation and a second angular orientation to fluidly connect separate sets of the transfer passages to separate sets of the spray orifices. Spray ducts are in spray path alignment with at least one of the sets of spray orifices.

Abstract: A piston for an internal combustion engine includes a piston having a bowl surface forming a combustion bowl, a rim surface forming an annular rim, and a gallery surface exposed to a backside cooling gallery of the piston. The bowl surface forms a bowl profile varied circumferentially around a piston center axis, and the gallery surface forms a gallery profile that is varied circumferentially around the piston center axis and is congruous with the bowl profile. The gallery surface is concave to the combustion bowl, convex to the backside cooling gallery, and forms no edges exposed within the backside cooling gallery. A wall formed between the combustion bowl and the backside cooling gallery has a heat-dissipation wall thickness defined by the varied bowl profile and the varied gallery profile.

Abstract: An ignition system for use with an engine is disclosed. The ignition system may have an igniter connected to selectively ignite a fuel mixture within the engine, an injector located to inject a non-combustible gas into the engine, and a controller in communication with the igniter and the injector. The controller may be configured to energize the igniter during a first mode of engine operation to ignite the fuel mixture, and cease energizing the igniter during a second mode of engine operation. The controller may also be configured to actuate the injector during the second mode of engine operation to promote auto-ignition of the fuel mixture.

Abstract: An ignition system for use with an engine is disclosed. The ignition system may have an igniter connected to selectively ignite a fuel mixture within the engine, an injector located to inject a non-combustible gas into the engine, and a controller in communication with the igniter and the injector. The controller may be configured to energize the igniter during a first mode of engine operation to ignite the fuel mixture, and cease energizing the igniter during a second mode of engine operation. The controller may also be configured to actuate the injector during the second mode of engine operation to promote auto-ignition of the fuel mixture.