Low-frequency acoustic center body

Patent metadata

Field	Value
Publication number	US-2023085562-A1
Application number	US-202117473715-A
Country	US
Kind code	A1
Filing date	Sep 13, 2021
Priority date	Sep 13, 2021
Publication date	Mar 16, 2023
Grant date	—

Abstract

A center plug for attenuating noise in a gas turbine engine includes an inner skin, the inner skin having a substantially cylindrical shape and extending along an axial centerline; an outer skin positioned radially outside the inner skin; a forward bulkhead disposed proximate a forward end of the inner skin, the forward bulkhead connected to and extending radially outward from the inner skin; an aft bulkhead disposed proximate an aft end of the inner skin, the aft bulkhead connected to and extending radially outward from the inner skin; and a first resonator cavity disposed within a volume defined by the inner skin, the outer skin and the forward bulkhead and the aft bulkhead, the first resonator cavity including a first perforated disk extending between the inner skin and the outer skin and forming a first sub-cavity and a second sub-cavity.

First claim

What is claimed is:

1 . A center plug for attenuating noise in a gas turbine engine, comprising:
an inner skin, the inner skin having a substantially cylindrical shape and extending along an axial centerline; an outer skin positioned radially outside the inner skin; a forward bulkhead disposed proximate a forward end of the inner skin, the forward bulkhead connected to and extending radially outward from the inner skin; an aft bulkhead disposed proximate an aft end of the inner skin, the aft bulkhead connected to and extending radially outward from the inner skin; and a first resonator cavity disposed within a volume defined by the inner skin, the outer skin and the forward bulkhead and the aft bulkhead, the first resonator cavity including a first perforated disk extending between the inner skin and the outer skin and forming a first sub-cavity and a second sub-cavity.

2 . The center plug of claim 1 , wherein the outer skin is connected to and positioned radially outward of the forward bulkhead, the aft bulkhead and the first perforated disk.

3 . The center plug of claim 2 , wherein the outer skin includes a first plurality of perforations extending into the first sub-cavity.

4 . The center plug of claim 3 , further comprising a first intermediate bulkhead disposed aft of the first perforated disk and extending between the inner skin and the outer skin.

5 . The center plug of claim 4 , wherein the first intermediate bulkhead is oriented at an angle with respect to the axial centerline.

6 . The center plug of claim 5 , wherein the angle is within a first range from about forty degrees to about eighty degrees with respect to the axial centerline.

7 . The center plug of claim 6 , wherein the first perforated disk is oriented within a second range from about minus ten degrees to about plus ten degrees with respect to a radial direction extending perpendicular to the axial centerline.

8 . The center plug of claim 7 , wherein the first intermediate bulkhead is configured to form a cone extending circumferentially about the axial centerline.

9 . The center plug of claim 8 , wherein the first perforated disk extends perpendicularly to the axial centerline.

10 . The center plug of claim 7 , wherein the first resonator cavity is configured to attenuate noise having frequencies within a range extending from about 200 Hz to about 1,000 Hz.

11 . The center plug of claim 7 , further comprising a second resonator cavity disposed within the volume defined by the inner skin, the outer skin and the forward bulkhead and the aft bulkhead, the second resonator cavity including a second perforated disk extending between the inner skin and the outer skin and forming a third sub-cavity and a fourth sub-cavity.

12 . The center plug of claim 11 , further comprising a second intermediate bulkhead disposed aft of the second perforated disk and extending between the inner skin and the outer skin.

13 . The center plug of claim 12 , wherein the second intermediate bulkhead is oriented at the angle with respect to the axial centerline.

14 . The center plug of claim 13 , wherein the second perforated disk is oriented within the second range from about minus ten degrees to about plus ten degrees with respect to the radial direction extending perpendicular to the axial centerline.

15 . The center plug of claim 14 , further comprising a third resonator cavity disposed within the volume defined by the inner skin, the outer skin and the forward bulkhead and the aft bulkhead, the third resonator cavity including a third perforated disk extending between the inner skin and the outer skin and forming a fifth sub-cavity and a sixth sub-cavity.

16 . The center plug of claim 15 , wherein the second resonator cavity is bounded by the first intermediate bulkhead and the second intermediate bulkhead and the third resonator cavity is bounded by the second intermediate bulkhead and the aft bulkhead.

17 . The center plug of claim 16 , wherein the outer skin includes a second plurality of perforations extending into the third sub-cavity and a third plurality of perforations extending into the fifth sub-cavity.

18 . A noise attenuation system for a gas turbine engine, comprising:
a center plug, the center plug including
an inner skin, the inner skin having a substantially cylindrical shape and extending along an axial centerline,
an outer skin positioned radially outside the inner skin,
a forward bulkhead disposed proximate a forward end of the inner skin, the forward bulkhead connected to and extending radially outward from the inner skin,
an aft bulkhead disposed proximate an aft end of the inner skin, the aft bulkhead connected to and extending radially outward from the inner skin; and
a first resonator cavity disposed within a volume defined by the inner skin, the outer skin and the forward bulkhead and the aft bulkhead, the first resonator cavity including a first perforated disk extending between the inner skin and the outer skin and forming a first sub-cavity and a second sub-cavity, the first perforated disk extending perpendicularly to the axial centerline extending through the center plug.

19 . The noise attenuation system of claim 18 , further comprising a second resonator cavity disposed within the volume defined by the inner skin, the outer skin and the forward bulkhead and the aft bulkhead, the second resonator cavity including a second perforated disk extending between the inner skin and the outer skin and forming a third sub-cavity and a fourth sub-cavity, the second perforated disk extending perpendicularly to the axial centerline extending through the center plug.

20 . The noise attenuation system of claim 19 , wherein the first resonator cavity and the second resonator cavity are separated by an intermediate bulkhead oriented at an angle within a range from about forty degrees to about eighty degrees with respect to the axial centerline.

Assignees

• Rohr Inc

Inventors

• Strutt Andrew John

Classifications

• F02K1/827

  Sound absorbing structures or liners · CPC title

• F02K1/04 Primary

  Mounting of an exhaust cone in the jet pipe · CPC title

• F05D2260/96

  Preventing, counteracting or reducing vibration or noise · CPC title

• F05D2260/963

  by Helmholtz resonators · CPC title

• G10K11/162

  Selection of materials · CPC title