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 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: An acoustic damper includes a housing with an inlet aperture and an outlet aperture. The housing is configured to receive a gas flow that enters via the inlet aperture and that exits via the outlet aperture. The acoustic damper also includes a barrier member that is disposed within the housing. The barrier member is configured to be disposed within the gas flow and to dampen acoustic energy that propagates in an upstream direction generally from the outlet aperture toward the inlet aperture. The barrier member includes an outer structure that defines an interior volume of the barrier member. The interior volume is oriented toward the outlet aperture.

Abstract: An acoustic damper includes an upstream wall with an inlet aperture and a downstream wall with an outlet aperture. The acoustic damper includes a first resonator that is supported by at least one of the upstream wall and the downstream wall. The acoustic damper also includes a second resonator that is supported by at least one of the upstream wall and the downstream wall. The first resonator and the second resonator are arranged in-parallel. Also, the first resonator and the second resonator are configured to cooperatively attenuate acoustic energy associated with a fluid flowing from the inlet aperture to the outlet aperture.

Abstract: An acoustic damper includes a housing with an inlet aperture and an outlet aperture. The housing is configured to receive a gas flow that enters via the inlet aperture and that exits via the outlet aperture. The acoustic damper also includes a barrier member that is disposed within the housing. The barrier member is configured to be disposed within the gas flow and to dampen acoustic energy that propagates in an upstream direction generally from the outlet aperture toward the inlet aperture. The barrier member includes an outer structure that defines an interior volume of the barrier member. The interior volume is oriented toward the outlet aperture.

Abstract: An acoustic damper includes an upstream wall with an inlet aperture and a downstream wall with an outlet aperture. The acoustic damper includes a first resonator that is supported by at least one of the upstream wall and the downstream wall. The acoustic damper also includes a second resonator that is supported by at least one of the upstream wall and the downstream wall. The first resonator and the second resonator are arranged in-parallel. Also, the first resonator and the second resonator are configured to cooperatively attenuate acoustic energy associated with a fluid flowing from the inlet aperture to the outlet aperture.