NOISE ATTENUATING LIPSKIN ASSEMBLY AND METHODS OF ASSEMBLING THE SAME

• US 20160024963A1
• Filed: 04/30/2014
• Published: 01/28/2016
• Est. Priority Date: 04/30/2014
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Lumbab, Alex C., Lan, Justin Honshune, Leisten, Bradley Scott
• Granted Patent: US 9,938,852 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B64D 2033/0206 comprising noise reduction means, e.g. acoustic liners
• CPC Class Codes: B64D 33/02 of combustion air intakes air intakes for gas-turbine plants or jet-propulsion plants per se F02C7/04; air intakes for combustion engines in general F02M35/00
• CPC Class Codes: E04B 1/8209 sound absorbing devices E04B1/8218, E04B1/8227 take precedence
• CPC Class Codes: F01D 25/04 Antivibration arrangements
• CPC Class Codes: F01D 25/24 Casings modified for heating or cooling F01D25/14; Casing parts, e.g. diaphragms, casing fastenings casings for rotary machines or engines in general F16M ; special arrangements in stators dealing with breaking-off of part of rotor F01D21/045
• CPC Class Codes: F02C 7/045 having provisions for noise suppression
• CPC Class Codes: F05D 2220/36 specially adapted for the fan of turbofan engines
• CPC Class Codes: F05D 2250/283 honeycomb
• CPC Class Codes: F05D 2260/96 Preventing, counteracting or reducing vibration or noise
• CPC Class Codes: F05D 2300/10 Metals, alloys or intermetallic compounds
• CPC Class Codes: F05D 2300/6012 Woven fabrics

Abstract

An acoustic assembly includes a backsheet including a plurality of perforations defined therethrough and an acoustic core coupled to the backsheet. The acoustic core includes a plurality of channels defined therethrough that are configured to be in flow communication with the plurality of perforations. The acoustic assembly also includes a linear facesheet coupled to the acoustic core, wherein the linear facesheet includes a plurality of apertures configured to be in flow communication with the plurality of channels. A lipskin is coupled to the linear facesheet, wherein the lipskin includes a plurality of openings configured to be in flow communication with the plurality of apertures.

Claims

1. An acoustic assembly comprising:

a backsheet comprising a plurality of perforations defined therethrough;

an acoustic core coupled to said backsheet, said acoustic core comprising a plurality of channels defined therethrough, wherein said plurality of channels are configured to be in flow communication with said plurality of perforations;

a linear facesheet coupled to said acoustic core, said linear facesheet comprising a plurality of apertures configured to be in flow communication with said plurality of channels; and

a lipskin coupled to said linear facesheet, said lipskin comprising a plurality of openings configured to be in flow communication with said plurality of apertures.

2. The acoustic assembly in accordance with claim 1, wherein said linear facesheet comprises at least one sheet of an expanded metal fabric, a felt metal fabric, and a woven wire mesh fabric.

3. The acoustic assembly in accordance with claim 1, wherein said linear facesheet comprises a plurality of sheets of expanded metal fabric that each include a plurality of passages defined therethrough, wherein said plurality of sheets are oriented such that said plurality of passages form a plurality of tortuous paths defined between said acoustic core and said lipskin.

4. The acoustic assembly in accordance with claim 3, wherein each sheet of said plurality of sheets has a thickness in a range of between approximately 0.002 inches and approximately 0.01 inches.

5. The acoustic assembly in accordance with claim 1, wherein said linear facesheet has a thickness in a range of between approximately 0.02 inches and approximately 0.10 inches.

6. The acoustic assembly in accordance with claim 1, wherein each opening of said plurality of lipskin openings is elongated in a direction of an airflow over said lipskin.

7. The acoustic assembly in accordance with claim 1, wherein plurality of openings is arranged on said lipskin such that said lipskin has a porosity in a range of between approximately 15 percent to approximately 30 percent open area.

8. The acoustic assembly in accordance with claim 1, wherein said lipskin forms a lip area of an engine nacelle.

9. The acoustic assembly in accordance with claim 1, wherein said acoustic core is a split-cell core comprising a first portion and a second portion, said acoustic core further comprising a linear fabric material coupled between said first portion and said second portion.

10. An engine nacelle comprising a lipskin assembly, said lipskin assembly comprising:

a backsheet comprising a plurality of perforations defined therethrough, said backsheet forming an inner surface of said nacelle;

an acoustic core coupled to said backsheet, said acoustic core comprising a plurality of channels defined therethrough, wherein said plurality of channels are configured to be in flow communication with said plurality of perforations;

a linear facesheet coupled to said acoustic core, said linear facesheet comprising a plurality of apertures configured to be in flow communication with said plurality of channels; and

a lipskin coupled to said linear facesheet, said lipskin comprising a plurality of openings configured to be in flow communication with said plurality of apertures such that a flow of heated air transpires through said acoustic core, said linear facesheet, and said lipskin to prevent ice formation on an outer surface of said lipskin, said lipskin forming an outer surface of said nacelle.

11. The engine nacelle in accordance with claim 10, wherein said linear facesheet comprises at least one sheet of an expanded metal fabric, a felt metal fabric, and a woven wire mesh fabric.

12. The engine nacelle in accordance with claim 10, wherein said linear facesheet comprises a plurality of sheets of expanded metal fabric that each include a plurality of passages defined therethrough, wherein said plurality of sheets are oriented such that said plurality of passages form a plurality of tortuous paths defined between said acoustic core and said lipskin.

13. The engine nacelle in accordance with claim 10, wherein said lipskin, said linear facesheet, said acoustic core, and said backsheet are sequentially layered to form said lipskin assembly.

14. The engine nacelle in accordance with claim 10, wherein plurality of openings is arranged on said lipskin such that said lipskin has a porosity in a range of between approximately 15 percent to approximately 30 percent open area.

15. A method of assembling a transpiring lipskin assembly, said method comprising:

coupling an acoustic core to a backsheet having a plurality of perforations defined therethrough, the acoustic core having a plurality of channels that are configured to be in flow communication with the plurality of perforations;

coupling a linear facesheet to the acoustic core, the linear facesheet having a plurality of apertures configured to be in flow communication with the plurality of channels; and

coupling a lipskin to the linear facesheet, the lipskin having a plurality of openings configured to be in flow communication with the plurality of apertures such that a flow of heated air transpires through the acoustic core, the linear facesheet, and the lipskin to prevent ice formation on an outer surface of the lipskin.

16. The method in accordance with claim 15, wherein the acoustic core is a split-cell core having a first portion and a second portion, said method further comprising coupling a linear fabric between the first and second portions.

17. The method in accordance with claim 15 further comprising forming the linear facesheet from at least one sheet of an expanded metal fabric, a felt metal fabric, and a woven wire mesh fabric.

18. The method in accordance with claim 17 further comprising forming the linear facesheet from a plurality of sheets of expanded metal fabric that each include a plurality of passages defined therethrough, wherein the plurality of sheets are oriented such that the plurality of passages form a plurality of tortuous paths defined between the acoustic core and the lipskin.

19. The method in accordance with claim 15, wherein coupling the lipskin to the linear facesheet further comprises coupling the lipskin wherein the plurality of openings is arranged on the lipskin such that the lipskin has a porosity in a range of between approximately 15 percent to approximately 30 percent open area.

20. The method in accordance with claim 15, wherein coupling the lipskin to the linear facesheet further comprises coupling the lipskin wherein each opening of the plurality of lipskin openings is elongated in a direction of an airflow over the lipskin.