The invention relates to an HPDF operation method for an internal combustion engine (100) with internal formation of a mixture and self-ignition, in which, (i) for a combustion cycle of an operation cycle under high pressure, as main fuel (63) at a first time point, the introduction of a nonself-igniting or gasoline engine fuel, and as ignition fuel (64) at a second time point, the introduction of a self-igniting or diesel fuel into a combustion chamber (20) of the internal combustion engine (1) are at least initiated and/or performed, (ii) a self-ignition of the ignition fuel (64) and with the self-ignition a nonself-ignition of the main fuel (63) are effected, and (iii) the self-ignition of the ignition fuel (64) is performed temporally and/or spatially in such a way that the main fuel (63) is ignited at a location (1) and/or in a region of an jet tip (630 and/or a propagation front (630 of a quantity of introduced main fuel (63)—in particular temporally firstly.

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.

An engine is provided, which includes a combustion chamber defined by a cylinder head and a piston inside a cylinder of a cylinder block, a fuel injection nozzle provided to the cylinder head and formed in a tip-end part with a plurality of injection holes from which fuel is injected into the combustion chamber, the tip-end part being exposed to the combustion chamber, and a passage-forming member formed with a passage through which the injected fuel passes. The injection holes include first and second injection holes, and the passage-forming member is disposed around the tip-end part of the nozzle so as to cause a difference between a speed at which fuel injected from the first injection hole flows toward a circumferential part of the combustion chamber, and a speed at which fuel injected from the second injection hole flows toward the circumferential part.

A weak tumble flow fast combustion system is provided. An intake throat and an exhaust throat are provided on a cylinder head, a section of an intake duct close to the intake throat is a tumble guide duct, an axis of the tumble guide duct is arranged obliquely with respect to the bottom surface of the cylinder head, and an upper side surface of the tumble guide duct is a flowing-down guide surface arranged obliquely with respect to the bottom surface of the cylinder head, a lower side surface of the tumble guide duct is an arc-shaped guide surface recessed toward the bottom surface of the cylinder head, an eccentric chamfer is provided at the lower end of the intake throat, and the eccentric direction of the eccentric chamfer is offset along the direction connecting the center of the intake throat to the exhaust throat.

A method for operating an internal combustion engine of a motor vehicle having a cylinder, the combustion chamber of which is delimited in the radial direction by a cylinder wall and in the axial direction by a piston and by a combustion chamber roof. The piston has an annularly peripheral piston stage which is arranged axially recessed in the piston compared with an annularly peripheral piston crown and which merges via an annularly jet splitter contour into a piston hollow arranged axially recessed in the piston in relation to the piston stage. An injector is allocated to the cylinder and via the injector several injection jets are simultaneously injected directly into the combustion chamber in a star shape for a combustion process.

An engine combustion chamber structure includes a combustion chamber of an engine and a fuel injection valve. The fuel injection valve injects fuel toward a cavity in a crown face of a piston. The cavity includes a first cavity provided in a radially central region of the crown face with a first bottom having a first depth, a second cavity provided in an outer side of the first cavity with a second bottom having a second depth being smaller than the first depth, a connecting portion, and a standing wall region disposed further in a radially outer side than the second bottom of the second cavity. The second bottom is provided lower than an upper end, of the connecting portion. A lower section of the standing wall region is provided further in a radially inner side than an upper edge of the standing wall region.

In a compression-ignition engine having a two-stage cavity, the distribution ratio between fuel for an upper cavity and fuel for a lower cavity is maintained even when the operational state of the engine changes. A piston of the compression-ignition engine includes a lower cavity, an upper cavity, and a lip portion between the lower cavity and the upper cavity. A controller causes a main injection and at least one pilot injection to be executed when the engine operates in a first state and a second state in which the load is higher than the load in the first state. The fuel spray is distributed to the lower cavity and the upper cavity. The controller causes a ratio of injection amount per pilot injection to the total injection amount to be higher when the engine operates in the second state than when the engine operates in the first state.

An engine management system and method may include a control system and method for controlling an internal combustion engine. The internal combustion engine may be a direct-injection engine using a Sonex Controlled Auto-Ignition (“SCAI”) combustion path. The control system and method may utilize fuel injection pressure, timing of start and end of injection, management of turbo airflow, fuel supplied, and other factors to provide reduced emissions and improved performance.

A diesel engine includes at least one cylinder (1) with a piston (2) having a piston bowl (3). A fuel injector (6) is configured to direct a fuel spray towards a target area (21) on an annular wall section (22) of the piston bowl so as to make a flame (20) formed by ignition of the fuel spray hit the target area. The target area borders, via a flow separation edge (23), on a lowered flow separation area (24) on the annular wall section so as to give this annular wall section a stepped configuration. The flow separation edge and flow separation area are configured to induce the formation of a vortex-filled wake between the flame and the flow separation area on the downstream side of the flow separation edge when the flame flows from the target area, across the flow separation edge and over the flow separation area.

Operating an internal combustion engine includes conveying fuel of spray plumes of directly injected fuel out of a swirl pocket in a combustion bowl in a piston, and impinging the fuel upon an anti-sooting ramp transitioning between a radially inner shelf surface of the combustion bowl and a radially outer squish surface of the piston. The shelf surface is spaced an axial distance (FA) from a plane defined by the squish surface that is from 1% to 2% of an outer diameter (OD) dimension of the piston. Impinging the fuel upon the anti-sooting ramp directs the fuel upwardly from the squish surface to limit wall-wetting in the combustion cylinder.