Abstract: A piston includes a piston crown defining a center axis and having a piston rim extending around a combustion bowl. The combustion bowl includes an injection-impingement surface extending a first partial circumferential extent around the axis, a bowl floor extending to a bowl wall, and a reentrant surface positioned opposite the injection-impingement surface and extending a second partial circumferential extent around the center axis. The combustion bowl further forms a fluid dispersion path originating at the injection-impingement surface traversing the bowl floor and the bowl wall and extending to the reentrant surface. A gaseous fuel internal combustion engine and related methodology are also disclosed.

Abstract: A gaseous fuel internal combustion engine includes a piston having a combustion face forming a piston rim surface and reciprocated in a cylinder in an engine housing. The engine also includes a gaseous fuel injector supported in a cylinder head of the engine housing. The combustion face includes an injection-impingement surface extending along the piston rim surface and spaced radially outward of a piston center axis, and a plurality of fuel-dispersal scallops. The scallops define a plurality of fuel paths advancing away from the injection-impingement surface and configured to disperse gaseous fuel in the cylinder so as to hasten mixing with air. The gaseous fuel may be a gaseous hydrogen fuel. Related methodology is also disclosed.

Abstract: Operating an engine system includes operating an electric-assist compressor in an air system for an engine while the engine is running, and operating the electric-assist compressor while the engine is not running. Pressurized air from operating the electric-assist compressor while the engine is not running is fed in a first flow pattern through the air system to purge a plurality of cylinders of the engine, and fed in a second flow pattern through the air system to a crankcase of the engine to purge the crankcase. Related apparatus in an engine system and an energized air system is also disclosed.

Abstract: Operating a gaseous fuel engine system includes opening and closing two intake valves for each of a plurality of intake ports to fluidly connect the intake ports to cylinders in an engine via two intake valve openings. Pressurized intake air is fed through each of the intake ports so as to define flow streamlines extending to inward sides of the respective two intake valve openings. Gaseous fuel admitted to each of the plurality of intake ports is advanced into cylinders in an engine in a manner proportionally concentrated around the respective flow streamlines. When advanced into the cylinders the gaseous fuel may be biased in distribution away from cylinder walls thereof. In an embodiment the gaseous fuel includes a gaseous hydrogen fuel. Related apparatus is also disclosed.

Abstract: An engine system includes an engine housing having an intake port to convey an incoming flow of intake air to a first intake valve opening and a second intake valve opening located downstream of the first intake valve opening. A port fuel injector assembly is supported in the engine housing and includes a fuel injector within a sleeve and an outwardly opening fuel injection valve. The sleeve includes a fuel-directing cap extending into the intake port and forming a fuel injection opening defining an outgoing fuel path axis oriented at a fuel exit angle, to improve distribution of a gaseous fuel such as a gaseous hydrogen fuel to the respective intake valve openings for mixing and combustion in an engine cylinder. Related apparatus of a port fuel injector assembly and methodology is also disclosed.

Abstract: An engine system operating and control strategy includes autoigniting a directly injected pilot fuel to ignite a primary fuel in a cylinder in a first engine cycle. The strategy further includes comparing data indicative of a heat release in a cylinder in the first engine cycle to phasing error criteria for an earlier pilot shot of the pilot fuel and a later shot of the pilot fuel. A quantity of one or more pilot shots in a subsequent engine cycle is varied, based on the comparison. Pilot shot quantity can be varied closed loop to obtain desired combustion phasing characteristics, such as when a characteristic of a primary fuel is changed during operation. Related apparatus and control logic is also disclosed.

Abstract: An engine system includes an engine housing forming a plurality of intake ports, and a plurality of fuel admission tubes each forming a fuel passage and at least one mixing air opening fluidly connected to the fuel passage between a first tube end and a terminal end surface of a second tube end. The mixing air opening may be formed in an end cap of the fuel admission tube. A plurality of mixing air openings in a fuel admission tube may have at least one of a circumferential distribution or an axial distribution that is biased in a direction of an incoming flow of intake air. Related apparatus and methodology is also disclosed.

Abstract: An engine system includes an engine housing forming a plurality of intake ports, and a plurality of fuel admission tubes each forming a fuel passage and at least one mixing air opening fluidly connected to the fuel passage between a first tube end and a terminal end surface of a second tube end. The mixing air opening may be formed in an end cap of the fuel admission tube. A plurality of mixing air openings in a fuel admission tube may have at least one of a circumferential distribution or an axial distribution that is biased in a direction of an incoming flow of intake air. Related apparatus and methodology is also disclosed.

Abstract: An engine system includes an engine housing having an intake port to convey an incoming flow of intake air to a first intake valve opening and a second intake valve opening located downstream of the first intake valve opening. A port fuel injector assembly is supported in the engine housing and includes a fuel injector within a sleeve and an outwardly opening fuel injection valve. The sleeve includes a fuel-directing cap extending into the intake port and forming a fuel injection opening defining an outgoing fuel path axis oriented at a fuel exit angle, to improve distribution of a gaseous fuel such as a gaseous hydrogen fuel to the respective intake valve openings for mixing and combustion in an engine cylinder. Related apparatus of a port fuel injector assembly and methodology is also disclosed.

Abstract: An engine system operating and control strategy includes autoigniting a directly injected pilot fuel to ignite a primary fuel in a cylinder in a first engine cycle. The strategy further includes comparing data indicative of a heat release in a cylinder in the first engine cycle to phasing error criteria for an earlier pilot shot of the pilot fuel and a later shot of the pilot fuel. A quantity of one or more pilot shots in a subsequent engine cycle is varied, based on the comparison. Pilot shot quantity can be varied closed loop to obtain desired combustion phasing characteristics, such as when a characteristic of a primary fuel is changed during operation. Related apparatus and control logic is also disclosed.

Abstract: Operating a hybrid power system for a machine includes combusting a direct injected gaseous hydrogen fuel in an engine operating an electrical generator, and increasing a load demand of the hybrid power system. Operating the hybrid power system further includes operating an electrical-assist compressor to supply an increased airflow into the engine based on an increased engine power demand to satisfy the increased load demand. Air-fuel equivalence ratio of the engine (so-called “lambda”) is maintained at a ratio of about 2 or greater to limit NOx emissions, and between a hydrogen fuel misfire limit and a hydrogen fuel preignition limit. Related apparatus and control logic is also disclosed.

Abstract: A gaseous fuel engine system includes an engine housing forming a plurality of intake ports, and a plurality of fuel admission tubes oriented to admit a gaseous fuel into the plurality of intake ports. The fuel admission tubes include mixers having flow-impinged surfaces exposed to at least one of a flow of gaseous fuel or a flow of intake air and each including a detachment edge. The mixers may include fins, wedge structures, and/or a contoured outer surface of the fuel admission tube. Related apparatus and methodology is also disclosed.

Abstract: Operating a hybrid power system for a machine includes combusting a direct injected gaseous hydrogen fuel in an engine operating an electrical generator, and increasing a load demand of the hybrid power system. Operating the hybrid power system further includes operating an electrical-assist compressor to supply an increased airflow into the engine based on an increased engine power demand to satisfy the increased load demand. Air-fuel equivalence ratio of the engine (so-called “lambda”) is maintained at a ratio of about 2 or greater to limit NOx emissions, and between a hydrogen fuel misfire limit and a hydrogen fuel preignition limit. Related apparatus and control logic is also disclosed.

Abstract: An engine includes a piston movable in a cylinder and having a combustion bowl, and an annular rim forming a scoop extending axisymmetrically around a piston center axis. A fuel injector tip extends into the cylinder and includes a first orifice set and a second orifice set offset from one another and offset from the piston center axis. A plurality of orifice-rim distances are defined between orifices in the second orifice set and an annular rim of the piston. The orifices in the second orifice set having a range of orifice sizes varied in direct relation to the respective orifice-rim distances. Related methodology is also disclosed.

Abstract: A gaseous fuel engine includes an engine housing having a cylinder block with a combustion cylinder therein, and an engine head including an intake port, an exhaust port, a fuel port, and an igniter bore, each extending to a fire deck. The gaseous fuel engine includes a fuel admission valve movable to close and open the fuel port. A non-axisymmetric clearance is defined between an inner port surface and the fuel admission valve and directionally biases a flow of gaseous fuel from the fuel port. Related methodology is also disclosed.

Abstract: An engine includes a piston movable in a cylinder and having a combustion bowl, and an annular rim forming a scoop extending axisymmetrically around a piston center axis. A fuel injector tip extends into the cylinder and includes a first orifice set and a second orifice set offset from one another and offset from the piston center axis. A plurality of orifice-rim distances are defined between orifices in the second orifice set and an annular rim of the piston. The orifices in the second orifice set having a range of orifice sizes varied in direct relation to the respective orifice-rim distances. Related methodology is also disclosed.

Abstract: A gaseous fuel engine includes an engine housing having a cylinder block with a combustion cylinder therein, and an engine head including an intake port, an exhaust port, a fuel port, and an igniter bore, each extending to a fire deck. The gaseous fuel engine includes a fuel admission valve movable to close and open the fuel port. A non-axisymmetric clearance is defined between an inner port surface and the fuel admission valve and directionally biases a flow of gaseous fuel from the fuel port. Related methodology is also disclosed.

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: 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: Operating an engine includes injecting a first charge of liquid fuel using a first set of nozzle outlets in a fuel injector, and injecting a second charge of liquid fuel using a second set of nozzle outlets in a fuel injector. The first charge is autoignited in a first engine cycle, and the second charge is autoignited in a second engine cycle, and may be used to pilot ignite a charge of gaseous fuel. Operating the engine further includes limiting errors in targeting of the second charge of liquid fuel caused by transitioning the engine from a first combination to a second combination of speed, load, and boost, by varying an injection pressure of the liquid fuel from the first engine cycle to the second engine cycle.