Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
  • F02C7/00—Features, components parts, details or accessories, not provided for in, or of interest apart form groups F02C1/00 - F02C6/00; Air intakes for jet-propulsion plants
  • F02C7/04—Air intakes for gas-turbine plants or jet-propulsion plants
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B64—AIRCRAFT; AVIATION; COSMONAUTICS
  • B64D—EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT
  • B64D29/00—Power-plant nacelles, fairings, or cowlings
  • B64D29/06—Attaching of nacelles, fairings or cowlings
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
  • F02C7/00—Features, components parts, details or accessories, not provided for in, or of interest apart form groups F02C1/00 - F02C6/00; Air intakes for jet-propulsion plants
  • F02C7/04—Air intakes for gas-turbine plants or jet-propulsion plants
  • F02C7/045—Air intakes for gas-turbine plants or jet-propulsion plants having provisions for noise suppression
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02K—JET-PROPULSION PLANTS
  • F02K1/00—Plants characterised by the form or arrangement of the jet pipe or nozzle; Jet pipes or nozzles peculiar thereto
  • F02K1/78—Other construction of jet pipes
  • F02K1/80—Couplings or connections
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02K—JET-PROPULSION PLANTS
  • F02K1/00—Plants characterised by the form or arrangement of the jet pipe or nozzle; Jet pipes or nozzles peculiar thereto
  • F02K1/78—Other construction of jet pipes
  • F02K1/82—Jet pipe walls, e.g. liners
  • F02K1/827—Sound absorbing structures or liners
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T50/00—Aeronautics or air transport
  • Y02T50/60—Efficient propulsion technologies, e.g. for aircraft
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/49826—Assembling or joining
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T403/00—Joints and connections
  • Y10T403/45—Flexibly connected rigid members

Definitions

• the present invention relates to an assembly for an aircraft propulsion system and a method for manufacturing such an assembly.
• a nacelle belonging to the propulsion system of the aircraft, generally has a structure comprising an air inlet upstream of the turbojet engine, a median section intended to surround a fan of the turbojet engine, a downstream section housing thrust reversal means and intended to surround the combustion chamber of the turbojet, and is generally terminated by an ejection nozzle whose output is located downstream of the turbojet engine.
• the air intake comprises, on the one hand, an inlet lip adapted to allow optimal capture to the turbojet of the air necessary to supply the blower and the internal compressors of the turbojet, and, of on the other hand, a downstream structure on which the lip is attached and intended to properly channel the air towards the blades of the fan.
• This downstream structure comprises in particular an annular inner wall 1, illustrated in FIGS. 1 and 2, and an outer cover (not shown) radially spaced from the inner wall 1.
• the inner wall 1 of the air intake structure is extended by a fan casing belonging to the median section of the nacelle in a direction parallel to the longitudinal axis of the turbojet engine.
• downstream end of the inner wall 1 of the air inlet and the upstream end of the blower housing each carry peripheral connecting flanges 2,3 for assembling said air inlet together. and the fan casing, using fasteners such as screws 4 or bolts.
• connection flange 2 of the air intake structure is respectively fixed downstream of the acoustic panel of the inner wall 1 or on the acoustic panel even by bolted elements 5.
• Air intake structures are also known in which the external connection and the connection flange to the corresponding fan casing are integrated in a single piece of composite material.
• the present invention aims to overcome these disadvantages.
• the present invention proposes an assembly for an aircraft propulsion system comprising a first ferrule intended to be fixed to a second ferrule and a first connecting flange intended to be fixed to a second corresponding connecting flange integral with the second ferrule.
• said first connecting flange comprising a plane portion extending in a radial direction with respect to the first ferrule characterized in that the connection between the first ferrule and the corresponding connecting flange is offset at a distance from the corresponding flange plane at a damping length of a moment generated by force flows through the first hole vi rol in predetermined condi tions of use of the set.
• the present invention avoids the appearance of delamination between the first ferrule and the connecting flange, insofar as at this particular distance, it avoids stressing the connection between the ferrule and the corresponding flange connection.
• the assembly according to the invention may comprise or more than one of the following characteristics, in particular: em ent or technically possible
• the first shell is an inner shell of an air intake structure of a nacelle and / or a structure of the inverter of the nacelle and / or a turbojet fan casing;
• the damping length I of said moment is defined on the following formula (1): wherein R and e respectively define the radius and thickness of the first ferrule and v, the fish coefficient of the material forming the first ferrule in line with the flange plane;
• the first ferrule and the corresponding first connecting flange are made of a single piece of composite material
• the first connecting flange is made of metallic material
• the first ferrule further comprises a transition wedge intended to be placed in line with the plane of the first flange between the latter and the first ferrule;
• the first ferrule further comprises a reinforcing plate attached to the connecting flange.
• the invention also relates to a method of manufacturing an assembly as mentioned above comprising a step in which a connection is carried between the first ferrule and the corresponding connection flange at a distance from the flange plane corresponding to a length of damping of a moment generated by force flows passing through said first ferrule under predetermined conditions of use of the assembly.
• FIG. 1 and 2 show partial sectional views of two assemblies of an air intake structure and a fan case of the state of the art
• FIG. 3 is a partial sectional view of an embodiment of an assembly of an air intake structure and a fan casing according to an embodiment of the present invention
• FIG. 4 is a detailed view of a method of manufacturing a flange for connecting a ferrule of the assembly of FIG. 3;
• - Figure 5 is a partial perspective view of a ferrule of the assembly of Figure 3 on which it has highlighted the different force flows present on the shell.
• An aircraft turbojet engine nacelle has a structure comprising an air inlet, a median section surrounding a turbojet fan, and a downstream section surrounding the turbojet and generally housing a thrust reversal system.
• the air intake structure is divided into two zones, namely on the one hand, an annular inlet lip aerodynamic profile adapted to allow optimal capture to the turbojet of the air necessary for the supply of air.
• the blower and internal compressors of the turbojet engine and, secondly, a downstream structure comprising an annular inner ring and an annular outer cover radially spaced from the inner shell, ferrule in te rn esurlaqu al is r pa rtée lal It is necessary to air the air to the blower.
• Such a ferrule is designated by the general reference 10 in FIG.
• This inner ferrule 10 of the air inlet structure is conventionally treated to form a sound attenuation structure 1 1 of the sound wave.
• It may include an air permeable inner skin, an outer breathable skin and a honeycomb honeycomb core.
• the middle section meanwhile, comprises on the one hand, an inner casing 20 surrounding the turbojet fan extending the inner shell 10 of the air intake structure and, on the other hand, an outer fairing structure of the casing extending the external hood of the air intake structure.
• the inner ferrule 10 is intended to be fixed to the fan casing 20 in a joint plane designated by the letter A, thanks to peripheral annular connection flanges 30, 40 placed respectively on the downstream end of the inner ferrule 10. and on the upstream end of the fan casing 20.
• Each connecting flange 30, 40 comprises a first connecting portion 31 forming a flange and extending in a radial direction and a second substantially cylindrical tubular connecting portion 32 extending in the longitudinal direction of the turbojet, so that the longitudinal section of the connection flange is L-shaped.
• connection flanges can be proposed.
• Each of the connecting flanges 30,40 protruding outwardly around the periphery of the inner shroud 10 of the air inlet and the blower housing 20 are pressed against each other by suitable fastening means. , parallel to the longitudinal axis of the turbojet and intended to pass through passages in each of the connecting flanges 30,40.
• the connecting flange 30 of the inner ferrule 10 is thus connected by any known means (not shown in FIG. 3), such as bolts, to the connection flange 40 of the casing 20 at the junction plane A.
• connection flanges 30, 40 may be associated with centering means making it possible to center the air intake structure with respect to the fan casing 20.
• the second connecting portion 32 of the flange 30 corresponding to the inner ferrule 10 of the air intake structure is intended to be fixed on said ferrule 10.
• this second connecting portion 32 forms a composite material part with the inner shell 10 of the air intake structure.
• This embodiment has the advantage of eliminating any fastening such as bolts or screws, which could alter the acoustic quality of the inner shell 10.
• connection between the inner ferrule 10 and the corresponding connection flange 30 is offset at a distance from the first portion 31 of the flange 30 corresponding to a characteristic quantity of a moment generated by the fluxes of through-forces said inner ferrule under predetermined conditions of use of the nacelle.
• connection bonded between the flange 30 and the acoustic panel 1 1 of the inner shell 10 is biased by forces in the plane, namely tension, compression and shearing in the plane, which lead to a bending moment in the plane. of the aforementioned ison generator of interlaminar shear.
• connection bonded between the flange 30 and the acoustic panel of the inner shell 10 is biased by force flows in the shell 10, namely axial tension and compression denoted by t, tension and circumferential compression denoted by f and shear plane designated by Ti 2 and the two associated arrows, shear in the wall of ferrule 10.
• the tension and the axial compression lead to a bending moment at the level of the aforesaid interlaminar-shedding ionic bond at the interface between the flange 30 and the ferrule 10.
• connection between the connecting flange 30 and the inner shroud 10 of the air intake structure is made substantially along the length of damping I at this time.
• Such a damping length is defined by the following formula (1):
• R is the radius of the ferrule
• e is the thickness of the ferrule
• v the fish coefficient of the material forming the ferrule at the first portion of the flange.
• the damping length can be defined by the formula ( 2) next approach:
• the connecting flange 30 is made of composite material.
• the damping length of the aforementioned moment is the length at which the moment becomes negligible.
• the acoustic panel of the inner shell 10 at this distance does not see the bending forces generated at the connection flange 30.
• connection flange 30 with the acoustic panel 11 of the inner ferrule 10 by eliminating the acoustic junction zones which act as a sonic bridge.
• connection allows the use of acoustic panel 11 comprising a low density honeycomb in the right of the connection flange 30, which has the advantage of promoting the reduction of mass of the panel 11 and of increase the acoustic surface of the latter.
• an alternative embodiment may provide a connection flange 30 of metal material whose connection with the inner ferrule 10 will be performed at the aforementioned damping length.
• a reinforcing plate 33 can be attached to the first connection portion 31 of the flange 30 corresponding to the inner ferrule 10 and fixed to the flange 30 by suitable means, if the requirements in terms of structural strength of the connection flange 30 require it.
• an alternative embodiment of the present invention proposes to insert a transition wedge 34 between the inner ferrule 10 and the connection flange 30 to the right of the first connecting portion 31 of the flange 30.
• this corner 34 is a profile having a section of generally triangular shape.
• This profile is formed of folds of glass or carbon, as well as a filler resin.
• this profile can be formed by pultrusion.
• This transition wedge 34 offers the advantage of improving the material health in the flange 30 / ferrule transition zone 10, that is to say, it makes it possible to avoid the deformation of the tissues at the place where it is square.
• connection flange 30 on the inner shroud 10 of the air intake structure a corresponding counter-form 35 is placed in place. that of the associated connection flange 30 that is desired to form and symmetrical to the latter.
• this counter-form 35 is contiguous on a rear skin 36 of the connecting flange 30 which has been previously cooked.
• connection flange 30 also comprises sacrificial pleats 37 placed behind the rear skin 36.
• connection flange 30 is draped over the counter-shape assembly 35 / rear skin 36.
• the invention is not limited to the embodiments of this nacelle, described above as examples, but it encompasses all variants.
• connection flange any ferrule of an assembly for an aircraft propulsion system comprising a connection flange and, in particular, to a structure of the inverter of the nacelle and / or the casing surrounding the blower of the turbojet engine. comprising an acoustic attenuation structure and the corresponding connection flange.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Aviation & Aerospace Engineering (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)
• Vibration Prevention Devices (AREA)
• Details Of Aerials (AREA)
• Turbine Rotor Nozzle Sealing (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=43301957

Family Applications (1)

Country Status (8)

Families Citing this family (6)

Family Cites Families (12)

• 2010
  • 2010-05-07 FR FR1053578A patent/FR2959726B1/fr active Active
• 2011
  • 2011-05-09 RU RU2012151435/11A patent/RU2570181C2/ru not_active IP Right Cessation
  • 2011-05-09 WO PCT/FR2011/051042 patent/WO2011138571A1/fr active Application Filing
  • 2011-05-09 CA CA2798005A patent/CA2798005A1/fr not_active Abandoned
  • 2011-05-09 BR BR112012026825A patent/BR112012026825A2/pt not_active IP Right Cessation
  • 2011-05-09 CN CN201180020769.4A patent/CN102858634B/zh not_active Expired - Fee Related
  • 2011-05-09 EP EP11725141A patent/EP2566757A1/de not_active Withdrawn
• 2012
  • 2012-11-07 US US13/671,233 patent/US9109509B2/en not_active Expired - Fee Related

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events