Methods and systems are provided for a piston. In one example, a system may comprise a plurality of first protrusions and a plurality of second protrusions working in tandem to confine an injection to a radial zone defined by the protrusions.

A 2-cycle, direct-injection diesel engine configured to accommodate low cetane diesel and jet fuels. The engine includes combustion chambers having surfaces which are operable at high temperatures during engine operation to increase the combustion rate of low cetane fuels. The engine is further configured to reduce starting times in cold and/or low pressure situations such as those experienced during attempts to restart a plane engine at relatively high altitudes.

A piston crown is provided for a piston in an internal combustion engine arrangement that includes a cylinder, the piston crown having a piston bowl surface adapted for facing a combustion chamber in the cylinder, wherein the piston bowl surface including a circumferential rim portion, a floor portion connected to and surrounded by the circumferential rim portion, a plurality of circumferentially spaced protrusions in the circumferential rim portion, at least one spray impingement portion, located between two adjacent protrusions. The spray impingement portion includes a reflection surface, being defined by that each possible normal to the reflection surface is directed towards a central axis of the piston, and forming an angle being within a range of a constant angle 10 with the central axis, wherein the constant angle is at least 50.

Internal combustion engine apparatuses, systems and methods. The internal combustion engine system includes a cylinder block including a cylinder bore and a piston movably positioned in the cylinder bore. The piston is configured to slide in an axial direction within the cylinder bore. The piston includes a piston crown and a turbulence induction protuberance extending in an axial direction from the piston crown. The turbulence induction protuberance is positioned radially intermediate an axial center of the piston and a circumferential portion of the piston. The turbulence induction protuberance is configured to cause turbulence in a propagating flame propagating from a central region of the cylinder bore to cause the propagating flame to extend to a circumferential portion of the cylinder bore.

A 2-cycle, direct-injection diesel engine configured to accommodate low cetane diesel and jet fuels. The engine includes combustion chambers having surfaces which are operable at high temperatures during engine operation to increase the combustion rate of low cetane fuels. The engine is further configured to reduce starting times in cold and/or low pressure situations such as those experienced during attempts to restart a plane engine at relatively high altitudes.

Methods and systems are provided for a piston. In one example, a system may comprise a plurality of first protrusions and a plurality of second protrusions working in tandem to confine an injection to a radial zone defined by the protrusions.

A diesel engine comprises: a cylinder head covering one end of a cylinder; a piston having a crown surface opposed to the cylinder head, and performing a reciprocating movement within the cylinder; and a fuel injector attached to the cylinder head. The cylinder head is formed with an intake port so as to generate a swirl flow within the cylinder. The crown surface of the piston is formed with a cavity which is recessed toward an opposite side of the cylinder head and which has a circular shape in planar view, and a notch which is recessed radially outward from a peripheral edge of the cavity. The fuel injector is formed with an injection hole oriented toward an inside of the cavity.

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.

In a diesel engine, a crown surface of a piston is formed with a cavity which is recessed toward an opposite side of a cylinder head, and which has a circular shape in planar view, and a wall surface forming the cavity includes a lip which is formed on a peripheral edge of the cavity, and which is protruded radially inward, and the lip is formed with a plurality of notches which are recessed radially outward from the peripheral edge of the cavity, and a fuel injector is arranged at a center of the cylinder head, and formed with a plurality of injection holes oriented toward an inside of the cavity so as to radially spray fuel within the cavity, and each of the plurality of the notches is arranged between oriented directions of two adjacent injection holes.

A 2-cycle, direct-injection diesel engine configured to accommodate low cetane diesel and jet fuels. The engine includes combustion chambers having surfaces which are operable at high temperatures during engine operation to increase the combustion rate of low cetane fuels. The engine is further configured to reduce starting times in cold and/or low pressure situations such as those experienced during attempts to restart a plane engine at relatively high altitudes.