Abstract: Operating a dual fuel engine system includes injecting an early shot and a second shot of a liquid fuel into a cylinder after a late closing timing of an intake valve, and producing a first and a second pilot flame based on ignition of the early shot and the second shot of liquid fuel. The early shot of liquid fuel is targeted such that a distribution of ignition points of the first pilot flame is biased outwardly of a combustion bowl in the piston. Propagation of the first and second pilot flames from geometrically distinct ignition locations rapidly increases pressure and temperature in the cylinder to provide fast combustion of a lean mixture of a gaseous fuel and air in a main charge in the cylinder.

Abstract: Operating a dual fuel engine system includes injecting an early shot and a second shot of a liquid fuel into a cylinder after a late closing timing of an intake valve, and producing a first and a second pilot flame based on ignition of the early shot and the second shot of liquid fuel. The early shot of liquid fuel is targeted such that a distribution of ignition points of the first pilot flame is biased outwardly of a combustion bowl in the piston. Propagation of the first and second pilot flames from geometrically distinct ignition locations rapidly increases pressure and temperature in the cylinder to provide fast combustion of a lean mixture of a gaseous fuel and air in a main charge in the cylinder.

Abstract: A method of controlling a dual fuel engine system includes adjusting a phasing control parameter such as air-fuel ratio (AFR), based on a phasing signal to limit an error in a phasing of combustion of gaseous fuel. The cylinder is switched to a dual fuel liquid pilot-ignited mode by commanding direct injection of an early pilot shot of liquid fuel, based on the adjustment to the phasing control parameter, and production of a spark to ignite gaseous fuel in the cylinder. Switching the cylinder to the dual fuel liquid pilot-ignited mode is completed by commanding direct injection of an early pilot shot and a second pilot shot of liquid fuel to ignite gaseous fuel in response to combustion of the early and second pilot shots in the cylinder.

Abstract: A liquid fuel injector for a fuel system in an internal combustion engine includes two injection control valves for controlling two outlet checks. A common nozzle supply cavity is fluidly connected to an inlet passage and supplies each of the two sets of nozzle outlets opened and closed by the outlet checks. A first nozzle outlet set forms a narrower spray angle and has a first combination of outlet number and outlet size, and a second nozzle outlet set forms a wider spray angle and has a second combination of outlet number and outlet size. The first nozzle outlet set has a greater steady flow than the second nozzle outlet set.

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 of operating a dual-fuel combustion system includes reciprocating a piston between a bottom dead center and a top dead center of a cylinder, the piston including a piston bowl, a circumferentially extending recess located radially outside of the piston bowl, and a plurality of diverters in the recess. The method includes opening an intake valve to introduce a first fuel, and injecting, by a set of fuel injector orifices substantially aligned with the diverters, a second fuel toward the diverters. The method also includes autoigniting the second fuel to ignite the first fuel.

Abstract: A piston for an internal combustion engine includes a piston head having a central axis and a top surface. The top surface of the piston includes a piston bowl, a circumferentially extending recess located radially outside the piston bowl, a plurality of diverters located within the recess, and a crown portion located radially outside the recess and extending to an outer surface of the piston.

Abstract: A method of operating a dual-fuel combustion system includes reciprocating a piston between a bottom dead center and a top dead center of a cylinder, the piston including a piston bowl, a circumferentially extending recess located radially outside of the piston bowl, and a plurality of diverters in the recess. The method includes opening an intake valve to introduce a first fuel, and injecting, by a set of fuel injector orifices substantially aligned with the diverters, a second fuel toward the diverters. The method also includes autoigniting the second fuel to ignite the first fuel.

Abstract: A piston for an internal combustion engine includes a piston head having a central axis and a top surface. The top surface of the piston includes a piston bowl, a circumferentially extending recess located radially outside the piston bowl, a plurality of diverters located within the recess, and a crown portion located radially outside the recess and extending to an outer surface of the piston.

Abstract: An igniter for a dual fuel engine includes a plurality of spray orifices formed in a nozzle and defining a plurality of spray axes. A plurality of spark electrodes are resident on the nozzle and form spark gaps offset from the spray axes, in a spark gap pattern that is at variance in at least one of a circumferential aspect or an axial aspect with the spray plume pattern.

Abstract: A component of a piston may include a crown portion configured to face a flame deck surface disposed at one end of a cylinder bore in which the piston is configured to reciprocate, such that a combustion chamber is defined within the cylinder bore and between a top surface of the crown portion and the flame deck surface. The component may include an indent formed in the top surface. The indent may be aligned with a fuel jet centerline along which a fuel jet is to be injected into the combustion chamber. The indent may include a first arcuate indent portion, that curves in a first direction from a center of the crown portion, and a second arcuate indent portion that curves in a second direction from a break in a reentrant feature that overhangs the first arcuate indent portion. The component may be included in an internal combustion engine.

Abstract: A combustion system for an internal combustion engine includes a cylinder having a cylinder wall defining a bore, a piston disposed inside the bore, a combustion chamber delimited by a cylinder head, the cylinder wall, and the piston. The piston includes a piston bowl defining a floor portion, and at least one scooped recess extending radially outwardly from a periphery of the piston bowl. The internal combustion engine further includes a fuel injector configured to inject fuel into the combustion chamber as a plurality of fuel jets at a main injection timing such that each fuel jet contacts the floor portion of the piston bowl and follows a profile of the piston bowl and enter the at least one scooped recess. Furthermore, at least one of the plurality of is deflected by the at least one scooped recess away from the cylinder wall.

Abstract: A fuel injector for an internal combustion engine is disclosed. The fuel injector includes a body defining an orifice. The orifice is configured to provide passage to a fuel into a combustion chamber of the internal combustion engine. The orifice includes an inlet port having a first oval shape and an outlet port having a second oval shape. The second al shape is orthogonal to the first oval shape. Moreover, a transition from the first oval shape to the second oval shape defines a stagnation plane, facilitating an exit of the fuel as a fan spray from the outlet port.

Abstract: A piston for an internal combustion engine includes a crown portion having a bowl that includes a plurality of protrusions. Each of the plurality of protrusions includes a first side surface and a second side surface. Other features including at least one ledge formed between protrusions in segments, and a generally flat, inward facing surface on the protrusions may also be used.

Abstract: A liquid fuel injector for a fuel system in an internal combustion engine includes two injection control valves for controlling two outlet checks. A common nozzle supply cavity is fluidly connected to an inlet passage and supplies each of the two sets of nozzle outlets opened and closed by the outlet checks. A first nozzle outlet set forms a narrower spray angle and has a first combination of outlet number and outlet size, and a second nozzle outlet set forms a wider spray angle and has a second combination of outlet number and outlet size. The first nozzle outlet set has a greater steady flow than the second nozzle outlet set.

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.

Abstract: A fuel injector includes a nozzle having at least one first orifice. The at least one first orifice selectively injects a first fuel. An outer check is located movably within the nozzle. The outer check includes at least one second orifice. The at least one second orifice selectively injects a second fuel. An inner check is located movably and concentrically within the outer check. The at least one first orifice is adapted to selectively inject at least one of the first fuel and the second fuel therethrough based on a position of each of the outer check and the inner check.

Abstract: A fuel injector includes a nozzle including at least one outer orifice. The at least one outer orifice selectively injects a first fuel. An outer check is disposed movably within the nozzle. The outer check includes at least one first orifice and at least one second orifice. The at least one first orifice and the at least one second orifice are disposed circumferentially spaced apart with respect to one another. Each of the at least one first orifice and the at least one second orifice selectively injects a second fuel. An inner check is disposed movably and concentrically within the outer check. The at least one outer orifice is adapted to selectively injects at least one of the first fuel and the second fuel therethrough based on a position of each of the outer check and the inner check.

Abstract: A fuel injector includes a nozzle having at least one first orifice provided therein. The at least one first orifice is adapted to selectively inject one of a fuel and an oxidant. An outer check is disposed movably within the nozzle. The outer check includes at least one second orifice provided therein. The at least one second orifice is adapted to selectively inject an other of the oxidant and the fuel. An inner check is disposed movably and concentrically within the outer chock. The at least one second orifice is adapted to align with respect to the at least one first orifice to selectively inject the fuel and the oxidant together through the at least one first orifice based on a position of each of the outer check and the inner check.

Abstract: A fuel system includes a fuel injector having a fuel passage and a purging fluid passage formed therein. A nozzle tip inner surface defines a sac forming a blind end of the fuel passage in the fuel injector. A coaxial concentric check assembly includes a purging check movable to admit a purging fluid such as pressurized air into the fuel passage to purge the sac of fuel. Reduced injector dribble is observed from the purging of fuel.