Abstract: A turbocharger turbine wheel can include a hub that includes a rotational axis, a backdisk and a nose, where the rotational axis defines an axial coordinate (z) in a cylindrical coordinate system that includes a radial coordinate (r) and an azimuthal coordinate (?) in a direction of intended rotation about the rotational axis; and blades that extend outwardly from the hub, where each of the blades includes a hub profile, a shroud edge, a leading edge, a trailing edge, a pressure side, and a suction side, where the hub profile includes a global maximum radius and a global minimum radius, and where, between the global maximum radius and the global minimum radius, in an axial direction from the backdisk to the nose, the hub profile includes a local minimum radius at a first axial coordinate position and a local maximum radius at a second axial coordinate position.

Abstract: A turbine housing assembly can include a turbine housing that defines a rotational axis for a turbine wheel; and a cartridge receivable by the turbine housing, where the cartridge includes a nozzle wall component with an upper nozzle surface and a plate component with a lower nozzle surface, where the upper nozzle surface and the lower nozzle surface define a nozzle space, and vanes positioned in the nozzle space, where the vanes are pivotable between a closed vanes position of 0 percent open and a fully open vanes position of 100 percent open, and where, for a vanes position of at least 50 percent open and less than 75 percent open, an axial dimension of the nozzle space increases with respect to decreasing radius as measured from the rotational axis.

Abstract: A 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 compressor housing upstream of the inlet-adjustment mechanism defines a series of acoustic cavities, and openings are defined in the compressor housing wall leading into the acoustic cavities. The openings and cavities are aimed at mitigating noise and flow pulsation in the air inlet caused when the inlet-adjustment mechanism is adjusted to the closed position to effectively reduce the inlet diameter approaching the compressor wheel.

Abstract: A turbine housing assembly can include a turbine housing that defines a rotational axis for a turbine wheel; and a cartridge receivable by the turbine housing, where the cartridge includes a nozzle wall component with an upper nozzle surface and a plate component with a lower nozzle surface, where the upper nozzle surface and the lower nozzle surface define a nozzle space, and vanes positioned in the nozzle space, where the vanes are pivotable between a closed vanes position of 0 percent open and a fully open vanes position of 100 percent open, and where, for a vanes position of at least 50 percent open and less than 75 percent open, an axial dimension of the nozzle space increases with respect to decreasing radius as measured from the rotational axis.

Abstract: A turbocharger turbine wheel can include a hub that includes a rotational axis, a backdisk and a nose, where the rotational axis defines an axial coordinate (z) in a cylindrical coordinate system that includes a radial coordinate (r) and an azimuthal coordinate (0) in a direction of intended rotation about the rotational axis; and blades that extend outwardly from the hub, where each of the blades includes a hub profile, a shroud edge, a leading edge, a trailing edge, a pressure side, and a suction side, where the hub profile includes a global maximum radius and a global minimum radius, and where, between the global maximum radius and the global minimum radius, in an axial direction from the backdisk to the nose, the hub profile includes a local minimum radius at a first axial coordinate position and a local maximum radius at a second axial coordinate position.

Abstract: A turbocharger includes a compressor equipped with an inlet-adjustment mechanism disposed in the air inlet of the compressor, the inlet-adjustment mechanism including a plurality of arcuate blades distributed about a circumference of a circle and partially overlapping one another so as to form an uninterrupted 360-degree blade ring. Each blade is pivotable about a respective fixed pivot point such that the ring is adjustable between a maximum-open position and a minimum-open position, the ring being adjustable via simultaneous coordinated pivoting of the blades about the respective fixed pivot points. The blades are structured and arranged to form said uninterrupted 360-degree blade ring in the maximum-open position and the minimum-open position and any intermediate position therebetween.

Abstract: A turbocharger includes an acoustic damper for attenuating noise from the compressor. The damper includes inner and outer duct walls defining an annular cavity therebetween, the outer duct being longer than the inner duct. An upstream wall bounds the annular cavity at the upstream end and defines an inlet aperture for fluid to pass through into the inner duct, and a downstream wall is axially spaced from the downstream end of the inner duct so as to define an expansion chamber fluidly connected to the annular cavity. The downstream wall defines an outlet aperture for the fluid. Partition walls between the two ducts partition the annular cavity into at least a first Helmholtz resonator and a first quarter-wave resonator that are axially serially arranged, and a second quarter-wave resonator that is circumferential serially arranged with respect to the first Helmholtz resonator.

Abstract: A turbocharger includes a compressor equipped with an inlet-adjustment mechanism disposed in the air inlet of the compressor, the inlet-adjustment mechanism including a plurality of arcuate blades distributed about a circumference of a circle and partially overlapping one another so as to form an uninterrupted 360-degree blade ring. Each blade is pivotable about a respective fixed pivot point such that the ring is adjustable between a maximum-open position and a minimum-open position, the ring being adjustable via simultaneous coordinated pivoting of the blades about the respective fixed pivot points. The blades are structured and arranged to form said uninterrupted 360-degree blade ring in the maximum-open position and the minimum-open position and any intermediate position therebetween.

Abstract: A 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 compressor housing upstream of the inlet-adjustment mechanism defines a series of acoustic cavities, and openings are defined in the compressor housing wall leading into the acoustic cavities. The openings and cavities are aimed at mitigating noise and flow pulsation in the air inlet caused when the inlet-adjustment mechanism is adjusted to the closed position to effectively reduce the inlet diameter approaching the compressor wheel.

Abstract: 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. Movement of the inlet-adjustment mechanism from the open position to the closed position is effective to shift the compressor's surge line to lower flow rates. The compressor includes a diffuser extending between an exducer of the compressor wheel and a volute for collecting pressurized air from the compressor. The diffuser is defined between first and second walls that diverge from each other in a radially outwardly direction through the diffuser. The divergent-wall diffuser enhances the shift of the surge line to lower flow rates when the inlet-adjustment mechanism is put in the closed position.

Abstract: A method for controlling an inlet-adjustment mechanism in an air inlet for a compressor so as to switch the mechanism between open and closed positions for adjusting a flow area of the inlet. The method includes an algorithm for determining when the inlet-adjustment mechanism is in a failure mode. In accordance with the method, when the operating point on the compressor map is on the high-flow side of a threshold line at which the inlet-adjustment mechanism is switched from one position to the other, a measured speed or pressure ratio is compared to a theoretical value for the speed or pressure ratio based on a compressor map for the open position of the mechanism. If the measured value differs from the theoretical value by more than a predetermined tolerance, a failure mode is indicated.

Abstract: A method for controlling an inlet-adjustment mechanism in an air inlet for a compressor so as to switch the mechanism in a binary fashion between open and closed positions for adjusting a flow area of the inlet. The method includes identifying a threshold line on a compressor map of pressure ratio versus corrected flow rate for the compressor, at which the inlet-adjustment mechanism is switched from one of its positions to the other. A fixed switch band straddling the threshold line can be used for determining when to initiate the switch of positions so as to time the switch to coincide with the operating point reaching the threshold line. Alternatively, a time to reach the threshold line can be instantaneously computed and compared to the actuator/mechanism response time.

Abstract: A 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 compressor housing upstream of the inlet-adjustment mechanism defines a series of acoustic cavities, and openings are defined in the compressor housing wall leading into the acoustic cavities. The openings and cavities are aimed at mitigating noise and flow pulsation in the air inlet caused when the inlet-adjustment mechanism is adjusted to the closed position to effectively reduce the inlet diameter approaching the compressor wheel.

Abstract: 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. Movement of the inlet-adjustment mechanism from the open position to the closed position is effective to shift the compressor's surge line to lower flow rates. The compressor includes a diffuser extending between an exducer of the compressor wheel and a volute for collecting pressurized air from the compressor. The diffuser is defined between first and second walls that diverge from each other in a radially outwardly direction through the diffuser. The divergent-wall diffuser enhances the shift of the surge line to lower flow rates when the inlet-adjustment mechanism is put in the closed position.

Abstract: A turbocharger includes an acoustic damper for attenuating noise from the compressor. The damper includes inner and outer duct walls defining an annular cavity therebetween, the outer duct being longer than the inner duct. An upstream wall bounds the annular cavity at the upstream end and defines an inlet aperture for fluid to pass through into the inner duct, and a downstream wall is axially spaced from the downstream end of the inner duct so as to define an expansion chamber fluidly connected to the annular cavity. The downstream wall defines an outlet aperture for the fluid. Partition walls between the two ducts partition the annular cavity into at least a first Helmholtz resonator and a first quarter-wave resonator that are axially serially arranged, and a second quarter-wave resonator that is circumferential serially arranged with respect to the first Helmholtz resonator.

Abstract: A 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. The inlet-adjustment mechanism includes a plurality of blades disposed about the air inlet, the blades being movable radially inwardly from an annular space of the air inlet wall, into the air inlet, so as to form an orifice of reduced diameter relative to a nominal diameter of the inlet. A noise-attenuator is disposed in the annular space, downstream of the inlet-adjustment mechanism, for attenuating aerodynamic noise induced by the inlet-adjustment mechanism when it is closed.

Abstract: A 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. The inlet-adjustment mechanism includes a plurality of blades disposed about the air inlet, the blades being movable radially inwardly from an annular space of the air inlet wall, into the air inlet, so as to form an orifice of reduced diameter relative to a nominal diameter of the inlet. A noise-attenuator is disposed in the annular space, downstream of the inlet-adjustment mechanism, for attenuating aerodynamic noise induced by the inlet-adjustment mechanism when it is closed.

Abstract: A centrifugal compressor for a turbocharger includes an inlet-adjustment mechanism operable to move between an open position and a closed position. The inlet-adjustment mechanism includes a plurality of blades disposed about the compressor air inlet and located between an upstream wall surface and a downstream wall surface of an annular space within the air inlet wall. The blades are pivotable about respective pivot points such that the blades extend radially inward from the annular space into the air inlet when the blades are in the closed position so as to form an orifice of reduced diameter relative to a nominal diameter of the inlet. Aerodynamic pressure balancing across the blades is achieved by spacing features that space a majority of the upstream surface of each blade from the opposing upstream wall surface.

Abstract: A method for controlling a VG mechanism for a compressor employs a predefined VG setpoint map comprising optimum VG setpoints for the VG mechanism based on at least one predefined optimization criterion. The VG mechanism has at least three different setpoints ranging between a minimum flow area setpoint and a maximum flow area setpoint. A location of an operating point of the compressor on its compressor map is determined. Based on the location of the operating point, the VG setpoint map is consulted and an optimum VG setpoint is determined. A predictive scheme can be included for accounting for time lag of the VG mechanism's response.

Abstract: A centrifugal compressor for a turbocharger includes an inlet-adjustment mechanism in an air inlet for the compressor, operable to move between a closed position, an open position, and a super-open position. The compressor also includes a ported shroud system. The inlet-adjustment mechanism includes a plurality of blades disposed about the air inlet and movable radially inwardly and outwardly for defining the various positions. In the closed position, the effective diameter of air inlet is reduced and the blades block flow through the ported shroud system. In the open position, the blades still block the ported shroud but the effective inlet diameter is increased relative to the closed position. In the super-open position, the blades unblock the ported shroud so that an additional amount of flow can pass through the ported shroud, thereby shifting the compressor's choke flow line to higher flow rates.