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 includes a compressor housing defining a cavity, and a compressor wheel disposed in the cavity, the compressor housing defining an inlet for leading air into the compressor wheel, a discharge volute for receiving air compressed by the compressor wheel, and a recirculation duct connected to the inlet at a location upstream of the compressor wheel. A recirculation valve is disposed between the discharge volute and the recirculation duct for regulating air flow through the recirculation duct into the inlet. The recirculation duct defines multiple parallel channels, the multiple parallel channels respectively conducting multiple parallel streams of air from the recirculation valve into the inlet.

Abstract: A compressor includes a compressor housing defining a cavity, and a compressor wheel disposed in the cavity, the compressor housing defining an inlet for leading air into the compressor wheel, a discharge volute for receiving air compressed by the compressor wheel, and a recirculation duct connected to the inlet at a location upstream of the compressor wheel. A recirculation valve is disposed between the discharge volute and the recirculation duct for regulating air flow through the recirculation duct into the inlet. The recirculation duct defines multiple parallel channels, the multiple parallel channels respectively conducting multiple parallel streams of air from the recirculation valve into the inlet.