Continuous degree of freedom acoustic cores

Patent metadata

Field	Value
Publication number	US-11915679-B2
Application number	US-202117540341-A
Country	US
Kind code	B2
Filing date	Dec 2, 2021
Priority date	Feb 1, 2017
Publication date	Feb 27, 2024
Grant date	Feb 27, 2024

Abstract

An acoustic liner is provided. The acoustic liner includes a face sheet, a back sheet spaced from the face sheet, and a core layer defining a cellular structure disposed between the face sheet and the back sheet. The core layer includes a plurality of first resonant cells coupled to the back sheet. Each of the first resonant cells includes a first cell wall coupled to the back sheet along a first cell wall base edge, the first cell wall extending from the back sheet toward the face sheet, the first cell wall further coupled to the face sheet along a first cell wall top edge, wherein the first cell wall of each of the first resonant cells comprises a surface extension that extends from a surface of the first cell wall.

First claim

What is claimed is:

1. An acoustic liner, comprising:
a face sheet;
a back sheet spaced from the face sheet; and
a core layer defining a cellular structure disposed between the face sheet and the back sheet, the core layer comprising:
a plurality of first resonant cells coupled to the back sheet, each of the first resonant cells comprising:
a first cell wall coupled to the back sheet along a first cell wall base edge, the first cell wall extending from the back sheet toward the face sheet, the first cell wall further coupled to the face sheet along a first cell wall top edge,
wherein the first cell wall of each of the first resonant cells comprises a surface extension that extends from a surface of the first cell wall to a distal end spaced from and disconnected from an opposing first cell wall, the face sheet, and the back sheet.

2. The acoustic liner of claim 1 , wherein the first cell wall of each of the first resonant cells has a thickness and the surface extension of each of the first cell walls has a length, wherein the length is greater than two times the thickness.

3. The acoustic liner of claim 1 , wherein each of the surface extensions extends from the surface of the first cell wall at a right angle.

4. The acoustic liner of claim 1 , wherein each of the surface extensions extends from the surface of the first cell wall at a non-orthogonal angle.

5. The acoustic liner of claim 1 , wherein each of the plurality of first resonant cells defines a cavity within that is defined by the face sheet, the back sheet, and a plurality of adjacent first cell walls, wherein the respective distal end of each of the surface extensions extends into one of the cavities and only partially toward at least one of the plurality of adjacent first cell walls.

6. The acoustic liner of claim 1 , wherein the first cell wall of each of the first resonant cells comprises a plurality of surface extensions that are spaced along the first cell wall, wherein a spacing between each of the plurality of surface extensions is non-uniform.

7. The acoustic liner of claim 1 , wherein the first cell wall of each of the first resonant cells extends arcuately between the face sheet and the back sheet.

8. The acoustic liner of claim 1 , wherein the first cell wall base edge has a first length and the first cell wall top edge has a second length, wherein the second length is less than the first length.

9. The acoustic liner of claim 1 , wherein the core layer comprises a plurality of second resonant cells, each of the second resonant cells comprising:
at least two second cell walls that are each coupled to the face sheet along a second cell wall base edge, each of the second cell walls extending from the face sheet toward the back sheet, the second cell wall further coupled to the back sheet along a second cell wall top edge; and
a second volume in a spaced defined by the at least two second cell walls, the back sheet, the face sheet, and at least two adjacent first resonant cells.

10. The acoustic liner of claim 9 , wherein the first cell wall base edge has a first length and the first cell wall top edge has a second length, wherein the second length is less than the first length, and wherein the second cell wall base edge has a third length and the second cell wall top edge has a fourth length, wherein the fourth length is less than the third length.

11. A turbofan engine comprising:
a fan rotor having a plurality of fan blades;
a nacelle surrounding the fan rotor;
a fan duct defined by the nacelle, the fan duct having a duct inner wall; and
an acoustic liner positioned along the duct inner wall of the fan duct, the acoustic liner, comprising:
a face sheet;
a back sheet spaced from the face sheet; and
a core layer defining a cellular structure disposed between the face sheet and the back sheet, the core layer comprising:
a plurality of first resonant cells coupled to the back sheet, each of the first resonant cells comprising:
a first cell wall coupled to the back sheet along a first cell wall base edge, the first cell wall extending from the back sheet toward the face sheet, the first cell wall further coupled to the face sheet along a first cell wall top edge,

wherein the first cell wall of each of the first resonant cells comprises a surface extension that extends from a surface of the first cell wall to a distal end spaced from and disconnected from an opposing first cell wall, the face sheet, and the back sheet.

12. The turbofan engine of claim 11 , wherein the acoustic liner has a thickness and a length, wherein the thickness of the acoustic liner varies along the length of the acoustic liner.

13. The turbofan engine of claim 11 , wherein the acoustic liner is positioned, at least partially, along the duct inner wall at a location upstream of the plurality of fan blades.

14. The turbofan engine of claim 11 , wherein the acoustic liner is positioned, at least partially, along the duct inner wall at a location downstream of the plurality of fan blades.

15. The turbofan engine of claim 11 , wherein the acoustic liner is positioned, at least partially, along the duct inner wall at a location radially outboard of the plurality of fan blades.

16. The turbofan engine of claim 11 , wherein the first cell wall of each of the first resonant cells has a thickness and the surface extension of each of the first cell walls has a length, wherein the length is greater than two times the thickness.

17. The turbofan engine of claim 11 , wherein the first cell wall of each of the first resonant cells extends arcuately between the face sheet and the back sheet.

18. The turbofan engine of claim 11 , wherein the first cell wall base edge has a first length and the first cell wall top edge has a second length, wherein the second length is less than the first length.

19. The turbofan engine of claim 11 , wherein the core layer comprises a plurality of second resonant cells, each of the second resonant cells comprising:
at least two second cell walls that are each coupled to the face sheet along a second cell wall base edge, each of the second cell walls extending from the face sheet toward the back sheet, the second cell wall further coupled to the back sheet along a second cell wall top edge; and
a second volume in a spaced defined by the at least two second cell walls, the back sheet, the face sheet, and at least two adjacent first resonant cells,
wherein the first cell wall base edge has a first length and the first cell wall top edge has a second length, wherein the second length is less than the first length, and wherein the second cell wall base edge has a third length and the second cell wall top edge has a fourth length, wherein the fourth length is less than the third length.

20. The turbofan engine of claim 11 , wherein each of the plurality of first resonant cells defines a cavity within that is defined by the face sheet, the back sheet, and a plurality of adjacent first cell walls, wherein the respective distal end of each of the surface extensions extends into one of the cavities and only partially toward at least one of the plurality of adjacent first cell walls.

Assignees

• Gen Electric
• Mra Systems Llc

Inventors

• Lin Wendy Wenling
• Martinez Michael Moses
• Majjigi Rudramuni Kariveerappa
• Calder David Patrick
• Goldsholl Aaron

Classifications

• G10K11/172 Primary

  using resonance effects · CPC title

• B32B3/12

  characterised by a layer of regularly- arranged cells, e.g. a honeycomb structure · CPC title

• B32B7/12

  using interposed adhesives or interposed materials with bonding properties · CPC title

• G10K11/168

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

• B32B2305/022

  Foam · CPC title