Low-frequency acoustic center body

Patent metadata

Field	Value
Publication number	US-12448935-B2
Application number	US-202418885392-A
Country	US
Kind code	B2
Filing date	Sep 13, 2024
Priority date	Sep 13, 2021
Publication date	Oct 21, 2025
Grant date	Oct 21, 2025

Abstract

A center plug includes an inner skin, the inner skin extending along an axial centerline; an outer skin positioned radially outside the inner skin; a forward bulkhead connected to and extending radially outward from the inner skin; an aft bulkhead connected to and extending radially outward from the inner skin; and an acoustic panel, the acoustic panel including a first sheet having a first plurality of perforated walls and a first plurality of non-perforated walls, a second sheet having a second plurality of perforated walls and a second plurality of non-perforated walls, the first sheet being sandwiched together with the second sheet to form an N-shaped structure having a combined plurality of perforated walls and a combined plurality of non-perforated walls.

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
an acoustic panel disposed within a volume defined by the inner skin, the outer skin and the forward bulkhead and the aft bulkhead, the acoustic panel including:
a resonator cavity comprised of a plurality of sub-cavities extending axially along the axial centerline and circumferentially about the axial centerline, the plurality of sub-cavities including a first sub-cavity, a second sub-cavity, and a third sub-cavity, the first sub-cavity being separated from the second sub-cavity in a circumferential direction by a first perforated wall, the second sub-cavity being separated from the third sub-cavity in the circumferential direction by a second perforated wall,
a first perforated surface extending in an axial direction and through the outer skin and into the first sub-cavity,
a non-perforated surface extending in the axial direction and covering the second sub-cavity, and
a second perforated surface extending in the axial direction and through the outer skin and into the third sub-cavity,
wherein the second perforated surface is spaced in the circumferential direction from the first perforated surface by the non-perforated surface.

2. The center plug of claim 1 , wherein the plurality of sub-cavities is defined by a first plurality of perforated walls oriented within a first range from about minus ten degrees to about plus ten degrees with respect to a radial direction extending perpendicular to the axial centerline.

3. The center plug of claim 2 , wherein the plurality of sub-cavities is defined by a second plurality of perforated walls oriented at an angle within a second range from about forty degrees to about eighty degrees with respect to the axial centerline.

4. The center plug of claim 3 , wherein the axial direction is selected such that attenuated acoustic waves exiting the second perforated surface are out of phase with non-attenuated acoustic waves transiting downstream of the first perforated surface.

Assignees

• Rohr Inc

Inventors

• Alonso-Miralles Jose S
• Robinson Ryan M

Classifications

• F05D2250/183

  zigzag · CPC title

• F05D2230/54

  by sheet metal manufacturing · CPC title

• F05D2230/60

  Assembly methods · CPC title

• F05D2250/75

  given by its similarity to a letter, e.g. T-shaped · CPC title

• F05D2250/314

  the axes being inclined in relation to each other · CPC title