Methods and apparatuses for integrated noise control and flow control in an aircraft environmental control system

Patent metadata

Field	Value
Publication number	US-9580178-B2
Application number	US-201514702407-A
Country	US
Kind code	B2
Filing date	May 1, 2015
Priority date	May 1, 2015
Publication date	Feb 28, 2017
Grant date	Feb 28, 2017

Abstract

Aircraft, environmental control systems, and air diffusers that may be used to create a quiet, comfortable environment within an aircraft cabin are disclosed. The air diffusers include a duct, a grille, and a porous flow conditioner positioned at least partially within an outlet plenum of the duct. The porous flow conditioner is configured to create backpressure and to reduce a velocity of air flowing out of the porous flow conditioner, relative to air flow unaffected by the porous flow conditioner. The porous flow conditioner may be configured to reduce noise generated by air flow through the air diffuser assembly, relative to air flow unaffected by the porous flow conditioner. The porous flow conditioner may be configured to reduce noise generated by air flow downstream of the porous flow conditioner.

First claim

The invention claimed is:

1. A quiet cabin air diffuser assembly comprising:
a duct having a duct inlet, a duct outlet downstream of the duct inlet, and an outlet plenum at least partially defined by the duct outlet;
a grille having a diffuser exit and a grille inlet upstream of the diffuser exit, wherein the grille is coupled to the duct outlet with the grille inlet facing the duct outlet and the outlet plenum; and
a porous flow conditioner positioned at least partially within the outlet plenum and transverse to air flow through the quiet cabin air diffuser assembly, wherein the porous flow conditioner spans at least 50% of an open area of the outlet plenum and at least partially defines an open channel in the outlet plenum that spans at least 10% of the open area of the outlet plenum;
wherein the porous flow conditioner is configured to create backpressure in the duct and to reduce a velocity of air flowing out of the porous flow conditioner toward the diffuser exit relative to a velocity of air flow unaffected by the porous flow conditioner, and wherein the porous flow conditioner is configured to reduce noise generated by air flow through the quiet cabin air diffuser assembly relative to noise generated by air flow unaffected by the porous flow conditioner.

2. The quiet cabin air diffuser assembly of claim 1 , wherein the porous flow conditioner is configured to reduce noise generated by air flow through the grille relative to noise generated by air flow unaffected by the porous flow conditioner.

3. The quiet cabin air diffuser assembly of claim 1 , wherein the quiet cabin air diffuser assembly is configured to generate a speech interference level of less than 50 dBA when air flows from the duct inlet through the diffuser exit at a flow rate greater than 200 g/min.

4. The quiet cabin air diffuser assembly of claim 1 , wherein the porous flow conditioner has an entrance and an exit downstream of the entrance, and wherein the porous flow conditioner is configured to establish an air flow profile at the grille inlet that is more uniform than an air flow profile at the entrance of the porous flow conditioner.

5. The quiet cabin air diffuser assembly of claim 1 , wherein the porous flow conditioner is configured to create an air pressure differential of greater than 1 kPa when an air flow into the duct is 2 m/s.

6. The quiet cabin air diffuser assembly of claim 1 , wherein the quiet cabin air diffuser assembly is configured to flow air greater than 500 g/min.

7. The quiet cabin air diffuser assembly of claim 1 , wherein the porous flow conditioner includes at least one of an open-cell foam, a reticulated foam, and a felt material.

8. The quiet cabin air diffuser assembly of claim 1 , wherein the porous flow conditioner is configured to transmit greater than 95% of airborne particles with an effective diameter of less than 100 μm.

9. The quiet cabin air diffuser assembly of claim 1 , wherein the porous flow conditioner includes a plurality of layers and wherein the layers are stacked in a direction of average air flow through the duct and the quiet cabin air diffuser assembly.

10. The quiet cabin air diffuser assembly of claim 9 , wherein a first layer of the plurality of layers is at least one of a screen panel, a mesh panel, a textile panel, and a fabric panel, wherein a second layer of the plurality of layers is at least one of a porous material, an open-cell foam, a reticulated foam, and a felt material, and wherein the second layer is downstream of the first layer.

11. The quiet cabin air diffuser assembly of claim 1 , wherein the porous flow conditioner is friction fit within the outlet plenum.

12. The quiet cabin air diffuser assembly of claim 1 , wherein a ratio of an open area of the diffuser exit to an open area of the duct inlet is greater than 4.

13. The quiet cabin air diffuser assembly of claim 1 , wherein the porous flow conditioner has an entrance and an exit downstream of the entrance, and wherein the porous flow conditioner defines a cavity that is open to one of the exit of the porous flow conditioner and the entrance of the porous flow conditioner.

14. The quiet cabin air diffuser assembly of claim 1 , wherein the open channel is positioned along an inward side of a bend in the duct.

15. The quiet cabin air diffuser assembly of claim 1 , wherein the duct includes a baffle plate upstream of the outlet plenum, wherein the baffle plate defines a plurality of channels through the baffle plate, and wherein an average effective diameter of the channels is at least 3 mm.

16. A quiet cabin air diffuser assembly comprising:
a duct having a duct inlet, a duct outlet downstream of the duct inlet, and an outlet plenum at least partially defined by the duct outlet;
a grille having a diffuser exit and a grille inlet upstream of the diffuser exit, wherein the grille is coupled to the duct outlet with the grille inlet facing the duct outlet and the outlet plenum; and
a porous flow conditioner positioned at least partially within the outlet plenum and transverse to air flow through the quiet cabin air diffuser assembly, wherein the porous flow conditioner spans at least 50% of an open area of the outlet plenum and at least partially defines an open channel in the outlet plenum that spans at least 10% of the open area of the outlet plenum;
wherein the porous flow conditioner is configured to create backpressure in the duct and to reduce a velocity of air flowing out of the porous flow conditioner toward the diffuser exit relative to a velocity of air flow unaffected by the porous flow conditioner from the duct inlet, and wherein the porous flow conditioner is configured to reduce noise generated by air flow downstream of the porous flow conditioner.

17. The quiet cabin air diffuser assembly of claim 16 , wherein the porous flow conditioner is configured to create an air pressure differential of greater than 1 kPa when an air flow from the duct is 240 L/min.

18. The quiet cabin air diffuser assembly of claim 16 , wherein the quiet cabin air diffuser assembly is configured to generate a speech interference level of less than 50 dBA when air flows from the duct inlet through the diffuser exit at a flow rate greater than 200 L/min.

19. The quiet cabin air diffuser assembly of claim 16 , wherein the quiet cabin air diffuser assembly is configured to emit air flow from the diffuser exit at a velocity of greater than 2 m/s.

20. An aircraft environmental control system including the quiet cabin air diffuser assembly of claim 16 , wherein the aircraft environmental control system is configured to supply air to an aircraft cabin through the quiet cabin air diffuser assembly.

Assignees

• Boeing Co

Inventors

• Bultemeier Eric James
• Barker Gail Mary
• Hlavka Brian Dale
• Jones Roderick M

Classifications

• F24F13/06

  Outlets for directing or distributing air into rooms or spaces, e.g. ceiling air diffuser · CPC title

• B64D13/06 Primary

  the air being conditioned (pressurising B64D13/02) · CPC title

• B64D13/00

  Arrangements or adaptations of air-treatment apparatus for aircraft crew or passengers, or freight space · CPC title

• B64D2013/0625

  comprising means for distribution effusion of conditioned air in the cabin · CPC title

• F24F13/24

  Means for preventing or suppressing noise · CPC title