Acoustic treatment in geared turbomachine

Patent metadata

Field	Value
Publication number	US-9890657-B2
Application number	US-201213593814-A
Country	US
Kind code	B2
Filing date	Aug 24, 2012
Priority date	Feb 28, 2012
Publication date	Feb 13, 2018
Grant date	Feb 13, 2018

Abstract

An example acoustic treatment for a geared turbomachine establishes a portion of the core cowl aft the fan cowl.

First claim

I claim:

1. A geared turbomachine assembly, comprising:
an acoustic treatment establishing a portion of a core cowl aft a fan cowl, the portion providing a radially inner boundary of a bypass flowpath, the acoustic treatment including a perforated face sheet, a backing sheet, and a cellular structure extending therebetween, the perforated face sheet having an open area density that is from 4 percent to 30 percent, wherein the core cowl is formed entirely by the acoustic treatment in some axial areas, wherein the acoustic treatment is in an unducted area of a geared turbomachine.

2. The geared turbomachine assembly of claim 1 , wherein the acoustic treatment extends from a position that is axially aligned with the fan cowl to a portion that is axially aligned with a low-pressure turbine section of the geared turbomachine assembly.

3. The geared turbomachine assembly of claim 1 , wherein the acoustic treatment extends axially to an aftmost end of the core cowl.

4. The geared turbomachine assembly of claim 3 , wherein the acoustic treatment extends continuously from a position that is axially aligned with the fan cowl to the aftmost end of the core cowl.

5. The geared turbomachine assembly of claim 1 , wherein the perforated face sheet comprises a microperforated face sheet having apertures with a diameter that is less than 25 percent of a thickness of the microperforated face sheet.

6. The geared turbomachine assembly of claim 1 , wherein the geared turbomachine assembly has a fan pressure ratio less than 1.45.

7. The geared turbomachine assembly of claim 1 , wherein the acoustic treatment forms a portion of the core cowl that provides a radially outer boundary of a core engine flowpath of the geared turbomachine assembly.

8. A geared turbomachine assembly, comprising:
an acoustic treatment establishing a portion of a core cowl aft a fan cowl, the portion providing a radially inner boundary of a bypass flowpath, the acoustic treatment including a perforated face sheet, a backing sheet, and a cellular structure extending therebetween, the perforated face sheet having an open area density that is from 4 percent to 30 percent, wherein a selected axial portion of the acoustic treatment is not secured to a walled structure, wherein the acoustic treatment extends from a position that is axially aligned with the fan cowl to a portion that is axially aligned with a low-pressure turbine section of the geared turbomachine assembly.

9. The geared turbomachine assembly of claim 8 , wherein the acoustic treatment extends axially to an aftmost end of the core cowl.

10. The geared turbomachine assembly of claim 9 , wherein the acoustic treatment extends continuously from a position that is axially aligned with the fan cowl to the aftmost end of the core cowl.

11. The geared turbomachine assembly of claim 8 , wherein the perforated face sheet comprises a microperforated face sheet having apertures with a diameter that is less than 25 percent of a thickness of the microperforated face sheet.

12. The geared turbomachine assembly of claim 8 , wherein the geared turbomachine assembly has a fan pressure ratio less than 1.45.

13. The geared turbomachine assembly of claim 8 , wherein the acoustic treatment is in an unducted area of a geared turbomachine.

14. The geared turbomachine assembly of claim 8 , wherein the acoustic treatment forms a portion of the core cowl that provides a radially outer boundary of a core engine flowpath of the geared turbomachine assembly.

15. A geared turbomachine assembly, comprising:
an acoustic treatment establishing a portion of a core cowl aft a fan cowl, the acoustic treatment including a perforated face sheet, a backing sheet, and a cellular structure extending therebetween, the perforated face sheet having an open area density that is from 4 percent to 30 percent, wherein the core cowl is formed entirely by the acoustic treatment in some axial areas, wherein the acoustic treatment forms a portion of the core cowl that provides a radially outer boundary of a core engine flowpath of the geared turbomachine assembly, wherein the acoustic treatment is in an unducted area of a geared turbomachine assembly.

Assignees

• Ali Amr
• United Technologies Corp

Inventors

• Ali Amr

Classifications

• F01D25/00 Primary

  Component parts, details, or accessories, not provided for in, or of interest apart from, other groups · CPC title

• F02C7/24

  Heat or noise insulation (air intakes having provisions for noise suppression F02C7/045; turbine exhaust heads, chambers, or the like F01D25/30; silencing nozzles of jet-propulsion plants F02K1/00) · CPC title

• Y02T50/672

  Cross-Sectional Technologies · mapped topic

• F05D2260/4031

  as in toothed gearing · CPC title

• F02K3/06

  with front fan · CPC title