Acoustic panel assembly with a folding chamber

Patent metadata

Field	Value
Publication number	US-9783316-B2
Application number	US-201514746345-A
Country	US
Kind code	B2
Filing date	Jun 22, 2015
Priority date	Jun 22, 2015
Publication date	Oct 10, 2017
Grant date	Oct 10, 2017

Abstract

An acoustic panel structure includes a perforated front sheet, a back sheet and a porous core between the front sheet and the back sheet. The acoustic panel structure also includes a non-perforated back cover which overlaps a portion of the back sheet. A portion of the back sheet is perforated and another portion of the back sheet is not perforated. An acoustic chamber is formed at least in part by the space between the back sheet and the back cover. The acoustic chamber may also be formed in part by the space between the front sheet and back cover. The space between the back sheet and the back cover is generally elongated in the x-y direction of the acoustic panel structure. This relatively thin acoustic panel structure is configured to attenuate long wavelength and low frequency noise.

First claim

I claim:

1. An acoustic panel structure for an aircraft propulsion system, comprising:
a first sheet configured with a first perforated region and a first non-perforated region;
a second sheet configured with a second perforated region;
a core configured with a plurality of cavities between the first perforated region and the second perforated region; and
a third sheet configured to form a chamber, a radial outer periphery of the chamber bounded by the second perforated region and the first non-perforated region and not by a perforated region of the first sheet;
wherein the first sheet is configured to partially form an inner radial boundary of a bypass gas path through the aircraft propulsion system, and wherein the first sheet is radially outboard of the second sheet and the third sheet.

2. The acoustic panel structure of claim 1 , wherein the core is radially between the first sheet and the second sheet, and the chamber radially overlaps the core.

3. The acoustic panel structure of claim 1 , wherein the core is radially between the first sheet and the second sheet, and a portion of the chamber is radially aligned with the core.

4. The acoustic panel structure of claim 1 , wherein the core is radially between the first sheet and the second sheet, and a portion of the chamber is circumferentially next to the core.

5. The acoustic panel structure of claim 1 , wherein the core is vertically between the first sheet and the second sheet, and a portion of the chamber is axially next to the core.

6. The acoustic panel structure of claim 1 , wherein the second sheet is configured with a second non-perforated region, and the core is configured with a plurality of second cavities between the first perforated region and the second non-perforated region.

7. The acoustic panel structure of claim 1 , wherein the core is connected between the first sheet and the second sheet, and the third sheet is connected to the first sheet and the second sheet.

8. The acoustic panel structure of claim 7 , wherein the core is bonded to the first sheet and the second sheet.

9. The acoustic panel structure of claim 7 , wherein the third sheet is bonded to the first sheet and/or the second sheet.

10. The acoustic panel structure of claim 7 , wherein the third sheet is mechanically fastened to the first sheet and/or the second sheet.

11. The acoustic panel structure of claim 1 , wherein a first portion of the chamber fluidly couples a second portion of the chamber with at least some of the cavities, and a radial thickness of the first portion of the chamber is less than a radial thickness of the second portion of the chamber.

12. An assembly for an aircraft propulsion system, comprising:
a nacelle for the aircraft propulsion system, the nacelle comprising:
an acoustic panel configured with a plurality of cavities fluidly coupled and vertically between a plurality of first perforations and a plurality of second perforations, the acoustic panel comprising a first sheet, a second sheet and a core between the first sheet and the second sheet; and
a back sheet connected to the acoustic panel;

wherein a chamber is between the acoustic panel and the back sheet, the chamber vertically overlaps the acoustic panel, and the chamber is bounded by a non-perforated region of the first sheet and not by any perforated region of the first sheet; and
wherein the second sheet is between the first sheet and the back sheet.

13. The assembly of claim 12 , wherein the acoustic panel is a composite bond panel.

14. An assembly for an aircraft propulsion system, comprising:
an inner fixed structure for the aircraft propulsion system, the inner fixed structure comprising:
an acoustic panel configured with a plurality of cavities fluidly coupled and vertically between a plurality of first perforations and a plurality of second perforations, the acoustic panel comprising a first sheet, a second sheet and a core between the first sheet and the second sheet; and
a back sheet connected to the acoustic panel;

wherein a chamber is between the acoustic panel and the back sheet, the chamber vertically overlaps the acoustic panel, and the chamber is only bounded by a non-perforated region of the first sheet; and
wherein the second sheet is between the first sheet and the back sheet.

15. The assembly of claim 14 , wherein the inner fixed structure partially forms a bypass gas path through the aircraft propulsion system, and the acoustic panel partially forms an inner radial boundary of the bypass gas path.

16. The assembly of claim 12 , wherein the nacelle at least partially forms a bypass gas path through the aircraft propulsion system, and the acoustic panel partially forms an inner boundary of the bypass gas path.

17. The acoustic panel structure of claim 1 , wherein all of the first sheet that bounds the chamber further fluidly separates the chamber from the bypass gas path.

18. The assembly of claim 14 , wherein is back sheet is arranged radially within the acoustic panel.

Assignees

• Rohr Inc

Inventors

• Alonso-Miralles Jose S

Classifications

• B64D33/06 Primary

  Silencing exhaust or propulsion jets · CPC title

• G10K11/168

  Plural layers of different materials, e.g. sandwiches · CPC title