A diesel engine of the present invention includes a turbocharger including: a turbine provided on an exhaust passage; a compressor provided on an intake passage; and a plurality of nozzle vanes provided around the turbine to control a flow velocity of an exhaust gas colliding with the turbine, angles of the nozzle vanes being changeable. In a case where a ratio of a volume of a combustion chamber when the intake valve is closed to a volume of the combustion chamber when a piston is located at a top dead center is denoted by an effective compression ratio ε.sub.e, and a total displacement of the engine is denoted by V (L), the effective compression ratio ε.sub.e is set to satisfy Formula (1) “−0.67×V+15.2≦ε.sub.e≦14.8.”

A ducted combustion system for an internal combustion. The ducted combustion system includes a combustion chamber, a fuel injector in fluid communication with the combustion chamber and configured to inject a sequence of at least two fuel charges into a combustion chamber during a combustion cycle and one or more ducts disposed within the combustion chamber and configured to receive at least a part of the fuel charges.

A fuel injector, comprising a nozzle body having a proximal end and a distal end, an upper row of nozzle holes being equally spaced about a first circumference of the nozzle body, and a lower row of nozzle holes located between the distal end and the upper row of nozzle holes, wherein the upper row has a first number of holes that is greater than a second number of holes in the lower row and wherein one of the first number of holes and the second number of holes is odd.

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.

The present disclosure relates to a combustion chamber of a diesel engine, which has a recessed combustion bowl to mix fuel injected from an injector with air, the combustion chamber including: a cylinder head which has the injector mounted thereto and is positioned at an upper side of the combustion bowl; a cylinder block which is positioned at a lower side of the cylinder head; and a piston which moves upward and downward in the cylinder block and faces the cylinder head, in which a plurality of radial inducers is provided on a bottom surface of the cylinder head around the injector.

Provided is an ignition control section and an injection control section. When partial compression ignition combustion is carried out, the ignition control section causes an ignition plug to carry out: main ignition in which a spark is generated in a late period of a compression stroke or an initial period of an expansion stroke to initiate SI combustion; and preceding ignition in which the spark is generated at earlier timing than the main ignition. Also, when the partial compression ignition combustion is carried out, the injection control section causes an injector to inject fuel at such timing that the fuel exists in a cylinder at an earlier time point than the preceding ignition. Ignition timing of the preceding ignition is set to be more retarded when an in-cylinder pressure specified by an in-cylinder pressure specification section is high than when the in-cylinder pressure is low.

A piston for an internal combustion engine is disclosed. The piston is configured to reciprocate along a centre axis of the piston during operation in an engine. The piston comprises a number of fuel directing surfaces arranged at a distance from a top surface of the piston measured along the centre axis . Each fuel directing surface is configured to direct a fuel spray sprayed onto the fuel directing surface. The fuel directing surfaces are arranged with gaps between two adjacent fuel directing surfaces. The present disclosure further relates to an engine comprising a piston and a vehicle comprising an internal combustion engine.

A fuel injector includes a nozzle body having spray orifices formed therein each defining a spray orifice diameter dimension (d), and a plurality of spray ducts each in spray path alignment with one of the plurality of spray orifices and including a duct outlet defining a duct exit diameter dimension (D). Each of the spray ducts defines, together with the respective one of the spray orifices, a relative spray area reduction (SAR) at the duct outlet. The ratio of D/d is at least 14, and the SAR is 80% or greater. The configuration provides reduced soot production. Related methodology is disclosed.

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.

A method for operating an internal combustion engine including a step of concurrently introducing at least two combustible fuel jets into a combustion chamber of an internal combustion engine. A first combustible fuel jet of the at least two combustible fuel jets is ignited at an ignition time point. In a first operating mode of the internal combustion engine a second combustible fuel jet which is different from the first combustible fuel jet of the at least two combustible fuel jets is ignited after the ignition time point.