Turbocharger system including acoustic damper for attenuating aerodynamically generated noise from compressor
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.
1. A turbocharger system, comprising:
a turbocharger comprising a turbine including a turbine housing, and a compressor including a compressor housing, the compressor housing defining an air inlet for conducting air into the compressor and a discharge pipe for conducting pressurized air out from the compressor; and
an acoustic damper coupled to one of the air inlet and the discharge pipe of the compressor, the acoustic damper comprising:
an upstream wall defining an inlet aperture therein;
a downstream wall defining an outlet aperture therein, the inlet and outlet apertures being spaced apart a distance D along an axial direction along which the fluid flows;
an inner duct for conducting the pressurized air received through the inlet aperture, the inner duct comprising an inner duct wall supported on the upstream wall and extending downstream from the upstream wall for a length L which is less than D;
an outer duct comprising an outer duct wall connected between the upstream wall and the downstream wall, the outer duct wall surrounding the inner duct wall such that an annular cavity is defined between the inner and outer duct walls, an expansion chamber being bounded between the downstream wall, the outer duct wall, and a downstream end of the inner duct wall, and wherein the annular cavity at a downstream end thereof is open to the expansion chamber; and
partition walls that extend between the inner and outer duct walls and partition the annular cavity into at least first and second quarter-wave resonators that are open to the expansion chamber and at least a first Helmholtz resonator, the inner duct wall defining at least one hole therethrough connecting the first Helmholtz resonator with an interior of the inner duct, wherein the first quarter-wave resonator and the first Helmholtz resonator are axially serially arranged with respect to each other, and the second quarter-wave resonator and the first Helmholtz resonator are circumferentially serially arranged with respect to each other.
2. The turbocharger system of claim 1 , wherein the first and second quarter-wave resonators have resonator lengths L 1 and L 2 respectively, wherein L 1 is less than L 2 .
3. The turbocharger system of claim 2 , wherein L 2 is equal to L.
4. The turbocharger system of claim 1 , wherein the partition walls further partition the annular cavity into a third quarter-wave resonator and a second Helmholtz resonator, the inner duct wall defining at least one hole therethrough connecting the second Helmholtz resonator with the interior of the inner duct, wherein the first, second, and third quarter-wave resonators are circumferentially serially arranged with respect to each other, and wherein the first and second Helmholtz resonators are circumferentially serially arranged with respect to each other.
5. The turbocharger system of claim 4 , wherein the partition walls further partition the annular cavity into a fourth quarter-wave resonator and a third Helmholtz resonator, the inner duct wall defining at least one hole therethrough connecting the third Helmholtz resonator with the interior of the inner duct, wherein the first, second, third, and fourth quarter-wave resonators are circumferentially serially arranged with respect to each other, and wherein the first, second, and third Helmholtz resonators are circumferentially serially arranged with respect to each other.
6. The turbocharger system of claim 5 , wherein the partition walls further partition the annular cavity into a fifth quarter-wave resonator and a sixth quarter-wave resonator, wherein the first, second, third, fourth, fifth, and sixth quarter-wave resonators are circumferentially serially arranged with respect to each other.
7. The turbocharger system device of claim 6 , wherein the third quarter-wave resonator and the second Helmholtz resonator are axially serially arranged with respect to each other, and wherein the fifth quarter-wave resonator and the third Helmholtz resonator are axially serially arranged with respect to each other.
8. The turbocharger system of claim 7 , wherein the first, third, and fifth quarter-wave resonators each has a resonator length L 1 , wherein L 1 is less than L.
9. The turbocharger system of claim 8 , wherein the second, fourth, and sixth quarter-wave resonators each has a resonator length L 2 , wherein L 2 is greater than L 1 .
10. The turbocharger system of claim 9 , wherein L 2 is equal to L.
11. The turbocharger system of claim 1 , wherein the acoustic damper is coupled to the air inlet.
12. The turbocharger system of claim 1 , wherein the acoustic damper is coupled to the discharge pipe.