A method to determine the mass of air trapped in each cylinder of an internal combustion engine, which comprises determining, based on a model using measured and/or estimated physical quantities, a value for a first group of reference quantities; determining, based on the model, the actual inner volume of each cylinder as a function of the speed of rotation of the internal combustion engine and of the closing delay angle of the intake valve; and calculating the mass of air trapped in each cylinder as a function of the first group of reference quantities and of the actual inner volume of each cylinder.

The invention relates to an internal combustion engine with an air intake system and an exhaust system is embodied as an internal combustion engine, in particular a gasoline engine, that is charged by means of an exhaust gas turbocharger. At least one three-way catalytic converter is arranged in the exhaust system of the internal combustion engine. Furthermore, a low-pressure exhaust gas recirculation system is provided that connects the exhaust system downstream from a turbine of the exhaust gas turbocharger and upstream from the at least one three-way catalytic converter to the air intake system upstream from a compressor of the exhaust gas turbocharger. The invention further relates to a method for exhaust aftertreatment of such an internal combustion engine.

Systems and methods for treated exhaust gas recirculation (EGR) for an internal combustion engine are disclosed. The internal combustion engine has an exhaust manifold discharging exhaust gas and an intake manifold receiving forced air from a compressor. One or more exhaust treatment devices treat the exhaust gas and produce a treated exhaust gas. The EGR system includes an EGR line downstream of the one or more exhaust treatment devices and connected to the engine intake line downstream of the compressor, wherein the treated EGR line recirculates the treated exhaust gas to the intake manifold of the engine without passing through the compressor.

Systems and methods for treated exhaust gas recirculation (EGR) for an internal combustion engine are disclosed. The internal combustion engine has an exhaust manifold discharging exhaust gas and an intake manifold receiving forced air from a compressor. One or more exhaust treatment devices treat the exhaust gas and produce a treated exhaust gas. The EGR system includes an EGR line downstream of the one or more exhaust treatment devices and connected to the engine intake line downstream of the compressor, wherein the treated EGR line recirculates the treated exhaust gas to the intake manifold of the engine without passing through the compressor.

An EGR device includes an inlet portion into which EGR gas is introduced, a first outlet portion, a second outlet portion, and a passage portion. The first outlet portion and the second outlet portion each conduct, to the corresponding branch passage portion, the EGR gas that has been introduced through the inlet portion. The passage portion allows gas to flow between the inlet portion and the first outlet portion and between the inlet portion and the second outlet portion. The passage portion includes: a main passage that connects the inlet portion to the first outlet portion and to the second outlet portion; and an expansion chamber that is expanded outward from the main passage. The main passage includes a connecting portion. The connecting portion is connected to the second outlet portion and extends in a first direction. The expansion chamber is expanded outward from the connecting portion.

An EGR device includes an inlet portion into which EGR gas is introduced, a first outlet portion, a second outlet portion, and a passage portion. The first outlet portion and the second outlet portion each conduct, to the corresponding branch passage portion, the EGR gas that has been introduced through the inlet portion. The passage portion allows gas to flow between the inlet portion and the first outlet portion and between the inlet portion and the second outlet portion. The passage portion includes: a main passage that connects the inlet portion to the first outlet portion and to the second outlet portion; and an expansion chamber that is expanded outward from the main passage. The main passage includes a connecting portion. The connecting portion is connected to the second outlet portion and extends in a first direction. The expansion chamber is expanded outward from the connecting portion.

The subject matter of this specification can be embodied in, among other things, a gas mixer that includes a convergent-divergent nozzle comprising a convergent portion and a divergent portion and defining a first gas flow path, an air housing comprising an air inlet configured to supply air to the first gas flow path upstream of the convergent-divergent nozzle, a gas housing defining a second gas flow path and including a first gas inlet configured to receive a secondary gas and allow the secondary gas into a second gas flow path, and a gas nozzle positioned parallel to and centrally within the first gas flow path in a convergent portion of the convergent-divergent nozzle, the gas nozzle configured to supply the secondary gas to the first gas flow path upstream of the divergent portion.

The subject matter of this specification can be embodied in, among other things, a gas mixer that includes a convergent-divergent nozzle comprising a convergent portion and a divergent portion and defining a first gas flow path, an air housing comprising an air inlet configured to supply air to the first gas flow path upstream of the convergent-divergent nozzle, a gas housing defining a second gas flow path and including a first gas inlet configured to receive a secondary gas and allow the secondary gas into a second gas flow path, and a gas nozzle positioned parallel to and centrally within the first gas flow path in a convergent portion of the convergent-divergent nozzle, the gas nozzle configured to supply the secondary gas to the first gas flow path upstream of the divergent portion.

An exhaust manifold comprises a plurality of exhaust intake conduits structured to be fluidly coupled to an engine and receive exhaust gas from a corresponding cylinder of the engine. At least one exhaust intake conduit provides a reduction in an exhaust intake conduit cross-sectional area from an inlet to an outlet. A plurality of bends are each defined by a respective one of the exhaust intake conduit outlets. An exhaust intake manifold is fluidly coupled to the exhaust intake manifold and defines an exhaust intake manifold flow axis. Each of the plurality of bends is shaped so as to define n angle of approach of exhaust gas flowing therethrough. A first angle of approach of the first bend relative to the exhaust intake manifold flow axis is smaller than a second angle of approach of an inner second bend.

A mixer for a gas flow system, such as an exhaust gas recirculation system, is provided. In one example, a gas flow system for an engine includes a first passage through which a first gas is configured to flow along a first axis; a second passage through which a second gas is configured to flow along a second axis, the first passage fluidly coupled to the second passage at an outlet of the first passage; and a mixer integrated with the first passage at the outlet and extending into the second passage, the mixer including an extension extending radially around the first axis and a main body extending into the second passage along the first axis.