A variable-capacity turbocharger includes a nozzle flow passage in which a gas is capable of flowing therethrough from a scroll flow passage toward a turbine impeller, a connecting pin connecting flow passage wall surfaces forming the nozzle flow passage, and nozzle vanes arranged in a rotation direction of the turbine impeller. At least one of the flow passage wall surfaces includes an inner peripheral side wall surface extending radially inward of a first reference line extending in the rotation direction, an outer peripheral side wall surface which is a plane extending radially outward from a second reference line extending in the rotation direction and parallel to a plane orthogonal to rotation axes of the nozzle vanes, and an intermediate wall surface which is a plane extending from the first reference line to the second reference line and parallel to the plane extending orthogonal to the rotation axes of the nozzle vanes.

A variable-capacity turbocharger includes a nozzle flow passage in which a gas is capable of flowing therethrough from a scroll flow passage toward a turbine impeller, a connecting pin connecting flow passage wall surfaces forming the nozzle flow passage, and nozzle vanes arranged in a rotation direction of the turbine impeller. At least one of the flow passage wall surfaces includes an inner peripheral side wall surface extending radially inward of a first reference line extending in the rotation direction, an outer peripheral side wall surface which is a plane extending radially outward from a second reference line extending in the rotation direction and parallel to a plane orthogonal to rotation axes of the nozzle vanes, and an intermediate wall surface which is a plane extending from the first reference line to the second reference line and parallel to the plane extending orthogonal to the rotation axes of the nozzle vanes.

An electronic control unit of an internal combustion engine is configured to control the fuel injection valve and to control a spark plug if necessary such that fuel is combusted by pre-mixture compression ignition combustion or flame propagation combustion. The electronic control unit is configured to perform homogeneous combustion in a flame ignition operation range when switching failure has not occurred, the homogeneous combustion being combustion in which fuel homogeneously diffused into the combustion chamber is ignited using the spark plug and is combusted by flame propagation combustion. The electronic control unit is configured to perform spray-guided stratified combustion in a second operation range when the switching failure has occurred, the spray-guided stratified combustion being combustion in which fuel in the fuel injection path is ignited using the spark plug and is combusted by the flame propagation combustion.

An electronic control unit of an internal combustion engine is configured to control the fuel injection valve and to control a spark plug if necessary such that fuel is combusted by pre-mixture compression ignition combustion or flame propagation combustion. The electronic control unit is configured to perform homogeneous combustion in a flame ignition operation range when switching failure has not occurred, the homogeneous combustion being combustion in which fuel homogeneously diffused into the combustion chamber is ignited using the spark plug and is combusted by flame propagation combustion. The electronic control unit is configured to perform spray-guided stratified combustion in a second operation range when the switching failure has occurred, the spray-guided stratified combustion being combustion in which fuel in the fuel injection path is ignited using the spark plug and is combusted by the flame propagation combustion.

Methods and systems for use of model predictive control (MPC) controllers utilizing hybrid, quadratic solvers to solve a linear feasibility problem corresponding to a nonlinear problem for an internal combustion engine plant such as a diesel engine air path. The MPC solves a convex, quadratic cost function having optimization variables and constraints and directs the plant per the output solutions to optimize plant operation while adhering to regulations and constraints. The problem includes a combination of iterative and direct calculations in the primal space depending on whether a partial step (iterative) or a full step (direct) is attempted. Further, primal and dual space array matrices are pre-computed and stored offline and are retrieved via use of a unique identifier associated with a specific active set for a set of constraints. Such hybrid and/or offline calculations allow for a reduction in computational power while still maintaining accuracy of solution results.

Methods and systems for use of model predictive control (MPC) controllers utilizing hybrid, quadratic solvers to solve a linear feasibility problem corresponding to a nonlinear problem for an internal combustion engine plant such as a diesel engine air path. The MPC solves a convex, quadratic cost function having optimization variables and constraints and directs the plant per the output solutions to optimize plant operation while adhering to regulations and constraints. The problem includes a combination of iterative and direct calculations in the primal space depending on whether a partial step (iterative) or a full step (direct) is attempted. Further, primal and dual space array matrices are pre-computed and stored offline and are retrieved via use of a unique identifier associated with a specific active set for a set of constraints. Such hybrid and/or offline calculations allow for a reduction in computational power while still maintaining accuracy of solution results.

A centrifugal compressor for a turbocharger includes an inlet-adjustment mechanism in an air inlet for the compressor, operable to move between an open position and a closed position in the air inlet. The inlet-adjustment mechanism includes a variable-geometry conical mechanism comprising a plurality of vanes that in the closed position collectively form a frusto-conical inlet member having a trailing edge inner diameter that is smaller than an inner diameter of the shroud surface of the compressor housing at the inducer portion of the compressor wheel such that an effective diameter of the air inlet at the inducer portion is determined by the trailing edge inner diameter of the variable-geometry conical mechanism. The vanes in the open position are pivoted radially outwardly so as to increase the trailing edge inner diameter of the inlet member and thereby increase the effective diameter of the air inlet at the inducer portion.

A centrifugal compressor for a turbocharger includes an inlet-adjustment mechanism in an air inlet for the compressor, operable to move between an open position and a closed position in the air inlet. The inlet-adjustment mechanism includes a variable-geometry conical mechanism comprising a plurality of vanes that in the closed position collectively form a frusto-conical inlet member having a trailing edge inner diameter that is smaller than an inner diameter of the shroud surface of the compressor housing at the inducer portion of the compressor wheel such that an effective diameter of the air inlet at the inducer portion is determined by the trailing edge inner diameter of the variable-geometry conical mechanism. The vanes in the open position are pivoted radially outwardly so as to increase the trailing edge inner diameter of the inlet member and thereby increase the effective diameter of the air inlet at the inducer portion.

In an effort to increase the reliability and net power and efficiency benefit of the axial- and mixed-flow turbocharger turbine, there is provided, a tapered, axially translatable (“sliding nozzle”) flow restrictor member to provide appropriate inlet exhaust gas flow characteristics for the operation of an axial or mixed flow turbine. The invention produces change of turbine flow with acceptable resolution at a lower cost than that for a conventional pivoting vane, variable geometry axial turbocharger turbine or at a similar cost but higher efficiency than a conventional sliding nozzle, variable geometry mixed, flow turbocharger turbine.

In an effort to increase the reliability and net power and efficiency benefit of the axial- and mixed-flow turbocharger turbine, there is provided, a tapered, axially translatable (“sliding nozzle”) flow restrictor member to provide appropriate inlet exhaust gas flow characteristics for the operation of an axial or mixed flow turbine. The invention produces change of turbine flow with acceptable resolution at a lower cost than that for a conventional pivoting vane, variable geometry axial turbocharger turbine or at a similar cost but higher efficiency than a conventional sliding nozzle, variable geometry mixed, flow turbocharger turbine.