Source: http://www.google.es/patents/US6827180
Timestamp: 2017-12-18 16:23:26
Document Index: 278465953

Matched Legal Cases: ['art.\n2', 'art.\n3', 'art.\n12', 'art.\n13', 'art.\n21', 'art.\n22', 'art.\n24', 'art.\n30']

Patente US6827180 - Noise attenuation panel - Google Patentes
A noise attenuation panel used to attenuate noise in aircraft engines includes a cellular core and a facing sheet formed with an array of holes. The holes are laser drilled to provide: (i) hole size variation over the facing sheet; (ii) non-circular hole cross section; (iii) polygonal hole cross section;...http://www.google.es/patents/US6827180?utm_source=gb-gplus-sharePatente US6827180 - Noise attenuation panel
Número de publicación US6827180 B2
Número de solicitud US 10/359,803
También publicado como US6609592, US20020036115, US20030141144
Número de publicación 10359803, 359803, US 6827180 B2, US 6827180B2, US-B2-6827180, US6827180 B2, US6827180B2
Inventores Robert Samuel Wilson
Cesionario original Short Brothers Plc
Citas de patentes (11), Citada por (44), Clasificaciones (30), Eventos legales (3)
US 6827180 B2
the method comprises producing, in a hole producing step, the multiplicity of holes through the facing component part in the form of an array of holes having a hole size which so varies over the facing component part as to provide optimum attenuating performance of the panel over a predetermined range of gaseous flow conditions at the front face of the facing component part.
2. The method according to claim 1, wherein the holes of the array are spaced apart with a hole spacing which varies over the facing component part.
3. The method according to claim 1, wherein the holes in the facing component part are produced by laser drilling.
4. The method according to claim 3, wherein the two component parts are assembled to form the noise attenuation panel after the laser drilling is performed.
5. The method according to claim 4, wherein the laser drilling is carried out using a high intensity laser.
6. The method according to claim 5, wherein the high intensity laser is a CO2 or YAG laser.
7. The method according to claim 3, wherein the two component parts are assembled to form the noise attenuation panel before the laser drilling is performed.
8. The method according to claim 7, wherein the laser drilling is carried out using a low intensity laser.
9. The method according to claim 8, wherein the low intensity laser is a UV Eximer laser.
10. A method of manufacturing a noise attenuation panel which comprises:
the method comprises producing, in a hole producing step, the multiplicity of holes through the facing component part in the form of an array of holes having a non-circular hole cross-section which is so chosen as to provide optimum combined structural strength and attenuating performance of the panel.
11. A method according to claim 10, wherein the holes of the array have a non-circular hole cross-section which varies over the facing component part.
12. The method according to claim 10, wherein the holes of the array are spaced apart with a hole spacing which varies over the facing component part.
13. The method according to claim 10, wherein the holes in the facing component part are produced by laser drilling.
14. The method according to claim 13, wherein the two component parts are assembled to form the noise attenuation panel after the laser drilling is performed.
15. The method according to claim 14, wherein the laser drilling is carried out using a high intensity laser.
16. The method according to claim 15, wherein the high intensity laser is a CO2 or YAG laser.
17. The method according to claim 13, wherein the two component parts are assembled to form the noise attenuation panel before the laser drilling is performed.
18. The method according to claim 17, wherein the laser drilling is carried out using a low intensity laser.
19. The method according to claim 18, wherein the low intensity laser is a UV Eximer laser.
20. A noise attenuation panel which comprises:
the multiplicity of holes through the facing component part form an array of holes having a hole size which so varies over the facing component part as to provide optimum attenuating performance of the panel over a predetermined range of gaseous flow conditions at the front face of the facing component part.
21. A panel according to claim 20, wherein the holes of the array are spaced apart with a hole spacing which varies over the facing component part.
22. A noise attenuation panel which comprises:
is provided with a multiplicity of holes which extend through the facing component part from the front face to the rear face to provide gaseous fluid communication between the cells of the cellular component part and the front
face of the facing component part for the attenuation of noise generated by gaseous fluid flow over the surface of the front face of the facing component part,
the multiplicity of holes through the facing component part form an array of holes having a non-circular hole cross-section which is so chosen as to provide optimum combined structural strength and attenuating performance of the panel.
23. A panel according to claim 22, wherein the holes of the array have a non-circular hole cross-section which varies over the facing component part.
24. A panel according to claim 22, wherein the holes of the array are spaced apart with a hole spacing which varies over the facing component part.
the multiplicity of holes through the facing component part form an array of holes which pass through the component part from the rear face of the facing component part to the front face of the facing component part in a predetermined hole direction inclined to the normal to the front face.
26. A panel according to claim 25, wherein the inclination of the holes is so chosen as to provide flow paths to the cell defining structure which optimise attenuating performance of the panel.
27. A panel according to claim 25, wherein the facing component part is a multi-ply structure comprising a plurality of superposed ply elements and wherein the holes are so inclined as to offset structural weakness of the multi-ply structure in the region of the holes.
28. A panel according to claim 25, wherein the panel is so located as to be subjected to gaseous fluid flow over the surface of the front face of the facing component part in a predetermined fluid flow direction and wherein the predetermined hole direction has a component along the front face of the facing component part which is in the same direction as the predetermined fluid flow direction.
29. A panel according to claim 25, wherein the holes are so inclined as to reduce the tendency of the holes to become clogged by debris carried in the gaseous fluid flow over the front face of the facing component part.
30. A noise attenuation panel which comprises:
a cell defining wall structure which defines a multiplicity of cells between the front face and the rear face and which terminate in end portions at the front face of the cellular component part, and
extends across the end portions of the cells of the cellular component part at the front face thereof with the rear face of the facing component part adjacent the front face of the cellular component part, and
no holes are provided at locations of the facing component part which in the assembled panel are contiguous with the end portions of the walls of the cell defining wall structure.
This application is a continuation of U.S. patent application Ser. No. 09/886,664, filed Jun. 20, 2001 now U.S. Pat. No. 6,609,592, which claims priority to GB 0016149.7, filed Jun. 30, 2000.
The perforate facing sheets of noise attenuation panels heretofore proposed have commonly been perforated by punching or mechanical drilling. Current noise attenuation panel constructions use perforate facing sheets with holes typically of diameter between 0.020″ (0.508 mm) and 0.060″ (1.524 mm)positioned in an equi-spaced triangular array such as to provide open areas within the limits of 3 and 20%.
In prior patent specification GB 2038410A it has been proposed to provide a noise attenuation panel for a fluid flow duct of a gas turbine aeroengine which is aimed at attenuating as many frequencies as possible by employing beneath the perforated facing sheet a Helmholtz-type resonator for frequencies at the lower end of the frequency range and tube-type resonators for higher frequencies. Attention is directed to varying the Helmholtz resonator characteristics to provide for a wide band absorption. The facing sheet has a regular array of uniformly-sized holes although it is proposed to increase the hole density by reducing the spacing between the holes at one location of the facing sheet for acoustic coupling purposes.
The present invention according to its different aspects includes a noise attenuation panel or the manufacture of a noise attenuation panel which comprises: a cellular component part which has a front face and a rear face and a cell defining wall structure which defines a multiplicity of cells between the front face and the rear face; and a facing component part which has a front face and a rear face, extends across the ends of the cells of the cellular component part at the front face thereof with the rear face of the facing component part adjacent the front face of the cellular component part, and is provided with a multiplicity of holes which extend through the facing component part from the front face to the rear face to provide gaseous fluid communication between the cells of the cellular component part and the front face of the facing component part for the attenuation of noise generated by gaseous fluid flow over the surface of the front face of the facing component part.
FIG. 7 is a schematic representation of a part of the facing sheet of the panel illustrated in FIGS. 2 and 3 as modified in accordance with the fourth and tenth aspects of the invention; and
As will be seen, the nacelle structure 12 includes at its forward end an inlet cowl 14 provided with noise attenuation panels 15 as hitherto proposed and constructed as hereinafter to be described with reference to FIG. 2 and 3.
To reduce noise emanating in the fan duct in the region of the thrust reversal unit, the inner wall 26 of the cowl 24 and the inner fan duct wall 32 are lined with noise attenuation panels 17 and 18 which may also take the form of a noise attenuation panel to be described with reference to FIG. 2 and 3.
As previously described, the holes 31 of the facing sheet 36 of the panel 33 have hitherto been of circular cross-section, of uniform size over the surface of the facing sheet 36 and uniformly distributed over the surface of the facing sheet 36. The holes 31 have been produced by conventional mechanical drilling, laser beam drilling or electron beam drilling prior to the assembly of the panel 33, that is to say, prior to the step of bringing the backing sheet 34, the cellular core 35 and the facing sheet 36 together.
Reinforcement: carbon (woven, undirectional, noncrimp fabric)
Typical construction: 3K carbon tows woven in a 8 harness configuration and epoxy matrix (3-4 plies 0.045″-0.60″ thick)
Core types: (i) nomex (aramid), (ii) glass reinforced phenolic dipped, (iii) metallic, e.g. Aluminum alloy
(Isolation layer may be used between metallic core and carbon composite component)
Scenario 1 (′Hot′ and ′Cold′
laser drilling)
(4) Reticulate adhesive onto honeycomb core or
perforated facing sheet
(5) Assemble backing sheet, honeycomb core and facing
sheet and bond together.
Scenario 2 (′Cold′ Laser Only)
(3) Assemble backing sheet, honeycomb core and facing
sheet and bond together
(The honeycomb core is bonded to the backing sheet with film adhesive. The core or the facing sheet is reticulated with adhesive to facilitate bonding at the honeycomb/facing sheet interface)
Perceived benefits and advantages gained by panels constructed with facing sheets having a hole geometry and distribution according to the invention in its different aspects are set out below.
Linear design studies have also indicated acoustic benefit from varying impedance properties (that is the open area) across the facing sheet. Analysis is also showing acoustic benefit to be gained from 3D distributed liners. Complex variation in hole geometry and distribution across the facing sheet is possible with the perforate liner, lending itself therefore to a very flexible liner design.
(iii) Hole geometry can be tapered through the thickness to reduce blockage effects and provides self cleaning mechanism.
In order to obtain high hole quality and rapid processing speeds, it is necessary to determine the optimum combination of parameters such as laser wavelength, repetition rate (“cutting speed”), pulse length, energy and drilling technique.
(ii) Trepanning Drilling
Whenever possible, heat generated during laser perforation should be allowed to dissipate, that is to say, prevented from building up to the level that would result in heat affected zones (HAZ)—burnt & missing resin and damaged fibres of the composite around hole. Normally, a laser operating at an Ultra Violet wavelength (200-400 nm)would be the best choice, as this would generate the minimum amount of heat. However, the cutting rate is too slow for production. An alternative way of minimising the heat is to use a laser operating at a visible or infrared wavelength but choose high laser energy pulse and keep the laser beam moving at high speed.
The following are the preferred types of Laser/ energy and repetition rates.
Solid state-Nd:YAG-flashlamp pumped 355, 532 & 1064 nm
High energy per pulse-low repetition rate.
Solid state-Nd:YAG-diode pumped 355 nm
Low energy per pulse-high repetition rate.
Solid state-Nd:YVO-diode pumped 1064 nm
Low energy per pulse-high repetition rate
Hot Lasers such as CO2 lasers may also be used because of their high cutting rates. They will, however, give rise to heat affected zones and a possible reduction in product quality.
US4288679 28 Feb 1980 8 Sep 1981 Fiat Auto S.P.A. Method of microdrilling metal workpieces using a power laser
US5804030 26 May 1994 8 Sep 1998 Hexacomb Corporation Apparatus for making prestressed honeycomb
US5841079 3 Nov 1997 24 Nov 1998 Northrop Grumman Corporation Combined acoustic and anti-ice engine inlet liner
US5912442 2 Jul 1997 15 Jun 1999 Trw Inc. Structure having low acoustically-induced vibration response
US6122892 5 Ago 1997 26 Sep 2000 Societe Hispano-Suiza Ventilated honeycomb cell sandwich panel and ventilation process for such a panel
US6615950 * 15 Nov 2001 9 Sep 2003 Airbus France Sandwich acoustic panel
EP0824066A1 13 Ago 1997 18 Feb 1998 Hispano-Suiza Ventilated honeycomb sandwich panel and ventilation method of such a panel
GB1490923A Título no disponible
GB2314526A Título no disponible
WO1994026995A1 10 May 1994 24 Nov 1994 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Sound-absorbent component made of glass or transparent synthetic glass
US7201254 4 Feb 2005 10 Abr 2007 Caterpillar Inc Machine housing component with acoustic media grille and method of attenuating machine noise
US7540354 * 26 May 2006 2 Jun 2009 United Technologies Corporation Micro-perforated acoustic liner
US7635048 19 Oct 2006 22 Dic 2009 Caterpillar Inc. Sound suppression device for internal combustion engine system
US7971684 * 19 Feb 2008 5 Jul 2011 Airbus Operations Sas Acoustic panel
US8469146 * 10 Feb 2012 25 Jun 2013 Airbus Operations Sas Panel for acoustic treatment comprising a junction between two parts and process for the reparation of a panel for acoustic treatment
US8579225 * 6 Oct 2011 12 Nov 2013 Snecma Device for acoustic treatment of the noise emitted by a turbojet
US8602156 * 19 May 2006 10 Dic 2013 United Technologies Corporation Multi-splice acoustic liner
US8615945 * 2 Jul 2012 31 Dic 2013 James Walker Ventilated structural panels and method of construction with ventilated structural panels
US8635822 * 23 Ago 2011 28 Ene 2014 James Walker Ventilated structural panels and method of construction with ventilated structural panels
US8640825 * 14 May 2009 4 Feb 2014 Aircelle Acoustic panel for an ejector nozzle
US8651233 * 8 May 2012 18 Feb 2014 Hexcel Corporation Acoustic structure with increased bandwidth suppression
US8685302 * 20 Feb 2012 1 Abr 2014 Honeywell International Inc. Monolithic acoustically-treated composite structures and methods for fabricating the same
US8707747 14 Dic 2012 29 Abr 2014 Rohr, Inc. Forming a shaped sandwich panel with a die and a pressure vessel
US8857566 17 Ene 2014 14 Oct 2014 Hexcel Corporation Acoustic structure with increased bandwidth suppression
US8960589 * 15 Dic 2010 24 Feb 2015 Airbus Operations Sas Panel for an air intake of an aircraft nacelle that ensures optimized acoustic treatment and frost treatment
US9091049 6 Dic 2013 28 Jul 2015 James Walker Ventilated structural panels and method of construction with ventilated structural panels
US9469390 6 Feb 2014 18 Oct 2016 Honeywell International Inc. Monolithic acoustically-treated composite structures and methods for fabricating the same
US9546602 * 12 May 2011 17 Ene 2017 Snecma Multi-layer acoustic treatment panel
US9728177 * 5 Feb 2015 8 Ago 2017 Dresser-Rand Company Acoustic resonator assembly having variable degrees of freedom
US20060174708 * 4 Feb 2005 10 Ago 2006 Redmann Michael A Machine housing component with acoustic media grille and method of attenuating machine noise
US20070209867 * 6 Abr 2007 13 Sep 2007 Jin Suk Kim Soundproof panel for impact sound insulation
US20070251212 * 28 Mar 2007 1 Nov 2007 Rolls-Royce Plc Aeroengine noise reduction
US20070267246 * 19 May 2006 22 Nov 2007 Amr Ali Multi-splice acoustic liner
US20070272483 * 26 May 2006 29 Nov 2007 Morin Bruce L Micro-perforated acoustic liner
US20080093159 * 19 Oct 2006 24 Abr 2008 Copley David C Sound suppression device for internal combustion engine system
US20080248300 * 5 Abr 2007 9 Oct 2008 United Technologies Corporation Processes for repairing erosion resistant coatings
US20090014234 * 3 Jul 2008 15 Ene 2009 Rolls-Royce Plc Acoustic Panel
US20100116587 * 19 Feb 2008 13 May 2010 Airbus France Acoustic panel
US20100307867 * 20 Sep 2007 9 Dic 2010 Masanori Ogawa Buffering and Sound-Absorbing Member
US20110108357 * 14 May 2009 12 May 2011 Aircelle Acoustic panel for an ejector nozzle
US20110139927 * 15 Dic 2010 16 Jun 2011 Airbus Operations Sas Panel for an air intake of an aircraft nacelle that ensures optimized acoustic treatment and frost treatment
US20120085861 * 6 Oct 2011 12 Abr 2012 Snecma Device for acoustic treatment of the noise emitted by a turbojet
US20120195739 * 13 Ene 2012 2 Ago 2012 Rolls-Royce Plc Attenuation of open rotor noise
US20120205192 * 10 Feb 2012 16 Ago 2012 Airbus Operations Sas Panel for acoustic treatment comprising a junction between two parts and process for the reparation of a panel for acoustic treatment
US20130142624 * 12 May 2011 6 Jun 2013 Snecma Multi-layer acoustic treatment panel
US20130145714 * 23 Ago 2011 13 Jun 2013 James Walker Ventilated structural panels and method of construction with ventilated structural panels
US20130213729 * 20 Feb 2012 22 Ago 2013 Honeywell International Inc. Monolithic acoustically-treated composite structures and methods for fabricating the same
US20160215700 * 23 Ene 2015 28 Jul 2016 Rohr, Inc. Inner fixed structure acoustic panel with directional perforations
EP2017826A3 * 20 Jun 2008 23 Nov 2016 Rolls-Royce plc An acoustic panel
Clasificación de EE.UU. 181/292
Clasificación internacional B23K26/38, B23K26/00, F02K1/82, F02C7/045, G10K11/172, B32B3/20, F02C7/24
Clasificación cooperativa B23K26/389, B23K2203/16, B23K26/384, B23K26/0006, F05D2260/96, B64D2033/0206, F02K1/827, B64D2033/0233, Y02T50/672, B64D2033/0286, G10K11/172, B32B3/20, F02C7/045, F02C7/24
Clasificación europea B23K26/00F14, B23K26/38B6, F02K1/82C, F02C7/045, B32B3/20, F02C7/24, G10K11/172, B23K26/38B2