Compressor recirculation system having compressor inlet recirculation duct configured to reduce noise from Rossiter excitation and cavity acoustic resonance
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.
1. A compressor comprising:
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 disposed between the discharge volute and the recirculation duct for regulating air flow through the recirculation duct into the inlet;
wherein the recirculation duct comprises two parallel channels respectively conducting two parallel streams of air from the recirculation valve into the inlet, the two channels being formed by a dividing wall that divides the recirculation duct in two, wherein the dividing wall has a length that extends along a flow direction through the recirculation duct, a thickness that extends parallel to an axial direction of the compressor, and a width that extends perpendicular to the flow direction and perpendicular to the axial direction of the compressor.
2. The compressor of claim 1 , wherein the two channels have equal cross-sectional areas on a cross-section that is perpendicular to a flow direction through the recirculation duct.
3. The compressor of claim 1 , wherein a length of the divider wall is less than a length of the recirculation duct.
4. A turbocharger, comprising:
a turbine comprising a turbine wheel disposed in a turbine housing, the turbine wheel being affixed to a shaft;
a compressor comprising a compressor wheel disposed in a cavity of a compressor housing, the compressor wheel being affixed to the shaft, 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 disposed between the discharge volute and the recirculation duct for regulating air flow through the recirculation duct into the inlet;
wherein the recirculation duct comprises two parallel channels respectively conducting two parallel streams of air from the recirculation valve into the inlet, the two channels being formed by a dividing wall that divides the recirculation duct in two, wherein the dividing wall has a length that extends along a flow direction through the recirculation duct, a thickness that extends parallel to an axial direction of the compressor, and a width that extends perpendicular to the flow direction and perpendicular to the axial direction of the compressor.
5. The turbocharger of claim 4 , wherein the two channels have equal cross-sectional areas on a cross-section that is perpendicular to a flow direction through the recirculation duct.
6. The turbocharger of claim 4 , wherein a length of the divider wall is less than a length of the recirculation duct.