HOOD FOR A TURBOMACHINE NACEL

Abstract

The invention relates to a hood for a nacelle comprising: - an annular outer panel (10a) centered on the longitudinal axis (X) and comprising a first composite material, the outer panel (10a) comprising external and internal faces (12a, 12b), - an annular seal (14), and - an annular seal track (13) arranged radially between the seal (14) and the outer panel (10a), the seal track (13) comprising external and internal annular faces (13a, 13b), the surface finish of the internal face (13b) being superior to the surface finish of the internal face (12b), and the seal (14) bearing against the internal face (13b) of the seal track (13), the internal face (12b) of the outer panel (10a) being bonded to the external face (13a) of the seal track (13), and the seal track (13) comprising a second composite material. Figure 3

Description

Description Title of the invention: COVER FOR A TURBO NACELLE BOMACHINE Technical field of the invention

[0001] The invention relates to the field of covers for turbomachine nacelles, in particular aircraft, in particular covers comprising an outer panel in composite material. Technical background

[0002] = An aircraft turbomachine typically comprises an engine comprising upstream downstream in the direction of gas flow, a mobile fan rotating around of a longitudinal axis, a low pressure compressor and a high pressure compressor pressure, a combustion chamber, a high pressure turbine and a low pressure turbine pressure and a gas exhaust nozzle.

[0003] — The blower allows the suction of an air flow dividing into a primary flow and a secondary flow. The primary flow passes through a primary vein of the turbomachine while that the secondary flow is directed towards a secondary vein surrounding the primary vein.

[0004] The primary flow is compressed within the compressors. The compressed air is then mixed with fuel and burned in the combustion chamber. The gases from the combustion passes through the turbines then escapes through the nozzle whose section allows the acceleration of these gases to generate propulsion.

[0005] The turbomachine further comprises a nacelle arranged around the engine. The nacelle is annular and extends around the longitudinal axis. It includes ty- stitching an air intake section, an engine section and a rear section. The engine section extends around the engine. It includes a cover including a exterior panel made of composite material. The exterior panel is typically made by draping within a mold and has external and internal faces whose states of different surface. The face with the best surface condition is the external face since it directly impacts the aerodynamic performance of the aircraft. By elsewhere, the outer panel is arranged around a casing. The casing and the panel exterior radially delimit an engine compartment. The rear section includes an annular hull defining a rear compartment. The hull typically houses a thrust reverser device. The engine and tail sections are connected axially but the engine and rear compartments must be isolated from each other to prevent fluid leaks or the spread of fire from one compartment to the other.

[0006] For this purpose, the hood typically comprises a seal arranged inside of the outer panel, sealingly separating the rear compartment from the engine compartment. In order to effectively ensure its sealing function, the seal must rest on a surface with a sufficient surface condition, in particular the lowest possible roughness Ra. However, the seal rests on the internal face which has a lesser surface condition compared to the external face. Therefore, it is known to arrange a sealing track made of metallic material between the seal and the outer panel. The sealing track has a better surface condition than that of the inner face of the outer panel and therefore improves the sealing of the hood. The seal track is typically riveted to the outer panel to prevent the assembly from separating, particularly in the event of a fire causing differential expansion of the seal track and the outer panel. Countersunk head fasteners therefore pass through the outer panel. The outer panel must be thick enough to accommodate the countersink of the fasteners. Indeed, if the countersunk head of the fasteners is outside the outer panel, then the aerodynamic performance of the turbomachine could be negatively impacted. This configuration is not entirely satisfactory. Since the seal track is made of metal, it considerably increases the weight of the cowl. Also, the oversizing of the outer panel to accommodate the fasteners further increases the weight of the cowl. Furthermore, securing the seal track to the outer panel using countersunk fasteners considerably increases the cowl's manufacturing time and cost. Finally, the presence of countersunk fasteners, although partially housed in the outer panel, contributes to reducing the aerodynamic performance of the turbomachine. Therefore, there is a need to provide a cowl for a nacelle of a turbomachine which is capable of providing optimum sealing, for example against fire and fluids, is lightweight, easy to manufacture and has good aerodynamic properties. Summary of the invention To this end, the invention provides a cowl for an aircraft turbomachine nacelle, the cowl extending around a longitudinal axis and comprising: - an annular outer panel centered on the longitudinal axis and comprising a first composite material, the outer panel comprising external and internal faces each having a surface condition, - an annular seal, and - an annular seal track arranged radially between the seal and the outer panel, the seal track comprising outer and inner annular faces having each a surface condition, the surface condition of the internal face of the joint track being superior, that is to say better, than the surface condition of the internal face of the external panel and the joint being supported on the internal face of the joint track. The hood is notable in that the inner face of the outer panel is bonded to the outer face of the seal track, and in that the seal track comprises a second composite material. The surface condition is characterized in particular by two main parameters which are the roughness R and the waviness W. The greater the roughness and / or waviness, the poorer the surface condition. According to the invention, the seal rests on the inner face of the seal track, which has a superior surface finish, i.e. better, than the surface finish of the inner face of the outer panel. The seal therefore rests on a surface with a good surface finish. The sealing of the seal resting on this face is therefore improved. Furthermore, according to the invention, the seal track is made of composite material and the outer panel is also made of composite material. Thanks to such a configuration, the risk of differential expansion in the event of a fire is limited. The seal track can therefore be secured to the outer panel by gluing. This therefore eliminates the need to secure these two elements of the cover by riveting, for example using countersunk head fasteners. The manufacturing time of the cover and the manufacturing cost are therefore considerably reduced.Also, since the seal track is made of composite material, the total mass of the hood is reduced. Finally, the thickness of the outer panel can be reduced compared to the prior art, thus reducing the mass of the hood. The invention may comprise one or more of the following features, taken in isolation from each other or in combination with each other: - the surface condition of the external face of the outer panel is superior, i.e. better, than the surface condition of the internal face of the outer panel, - the surface condition of the inner face of the joint track is superior, i.e. better, than the surface condition of the outer face of the joint track, - the external and internal faces of the outer panel each have a roughness R, and the external and internal annular faces of the joint track each have a roughness R, the roughness R of the internal face of the joint track being less than the roughness R of the internal face of the outer panel, - the roughness R of the external face of the outer panel is less than the roughness R of the internal face of the outer panel, - the roughness R of the internal face of the joint track is less than the roughness R of the external face of the joint track, - the internal face of the joint track has a roughness Ra which is less than or equal to 8 um, less than or equal to 6.5 jm, less than or equal to 6.4 jm, less than or equal to 4 um, less than or equal to 3.5 um, less than or equal to 3.2 um, less than or equal to 0.8 um, - the external and internal faces of the outer panel each have a corrugation W, and the external and internal annular faces of the joint track each have a corrugation W, the corrugation W of the internal face of the joint track being less than the corrugation W of the internal face of the outer panel, - the corrugation W of the external face of the outer panel is less than the corrugation W of the internal face of the outer panel, -the undulation W of the inner face of the joint track is less than the undulation W of the outer face of the joint track, - the internal face of the joint track has a corrugation Wa which is less than or equal to 0.8 mm, - the second composite material comprises a polymer matrix and reinforcing fibers embedded in the matrix, - the fibers are chosen from carbon fibers or glass fibers or aramid fibers or a mixture thereof, - the second composite material comprises at least one layer or ply of fibers, preferably a superposition of layers or plies of fibers, - the joint track has a thickness (e) between 0.1 mm and 10 mm, - an annular angle iron, one axial wing of which is surrounded by the seal, the seal being arranged radially between the axial wing of the angle iron and the seal track. The invention also relates to a nacelle for an aircraft turbomachine, comprising a cowl according to any one of the preceding characteristics. The nacelle according to the invention may include the following characteristics: - an engine section comprising the hood and a casing arranged inside the hood, the hood and the casing radially delimiting an engine compartment, and - a rear section comprising an annular hull defining a rear compartment, and - a radial annular partition axially separating the engine compartment from the rear compartment, the angle iron being connected to the partition. The invention also relates to a method of manufacturing a cowl for an aircraft turbomachine nacelle, according to any one of the preceding characteristics, the method comprising the following steps: (a0) manufacture the outer panel, (al) manufacture the joint track, (a2) glue the outer face of the joint track to the inner face of the outer panel, then (a3) place the annular seal resting on the internal face of the seal track. The method according to the invention may comprise the following characteristic: - in step (al) the joint track (13) is manufactured by draping. Brief description of the figures Other characteristics and advantages will emerge from the following description of a non-limiting embodiment of the invention with reference to the appended drawings in which: [Fig. 1] is a schematic longitudinal sectional view of an aircraft turbomachine, [Fig.2] is a schematic perspective view of the nacelle according to the invention equipping for example the turbomachine of [Fig.1], [Fig.3] is a detail view of the nacelle cover of [Fig.2], [Fig.4] is a detailed schematic view in longitudinal section of the seal track fitted to the hood of [Fig.3], [Fig.5] is a schematic cross-sectional view of a draping device, [Fig.6] is a schematic view of a method according to the invention. Detailed description of the invention An example of an aircraft turbomachine 1 according to the invention is shown in [Fig. 1]. The turbomachine 1 extends around and along a longitudinal axis X. In this application, the terms "axial", "axially", "radial" and "radially" are defined with respect to the longitudinal axis X. The terms “upstream”, “downstream”, “front” and “rear” are defined in relation to the direction of gas flow in the turbomachine 1 along the longitudinal axis X. The terms "internal", "interior", "external", "exterior", "externally" are defined in relation to the distance from the longitudinal axis X along a radial axis perpendicular to the longitudinal axis X. The turbomachine | comprises an engine comprising, from upstream to downstream, a fan 2 and a gas generator. The gas generator comprises, from upstream to downstream, at least one compressor such as a low-pressure compressor 3 and a high-pressure compressor 4, a combustion chamber 5, at least one turbine such as a high-pressure turbine 6 and a low-pressure turbine 7. The blower 2 allows the suction of an air flow F dividing into a primary flow F1 and a secondary flow F2. The primary flow F1 passes through a primary vein of the turbomachine | while the secondary flow F2 is directed towards a secondary vein surrounding the primary vein. The primary flow F1 is compressed within the low pressure compressor 3 then the high pressure compressor 4. The compressed air is then mixed with a fuel and burned within the combustion chamber 5. The gases formed by the combustion pass through the high pressure 6 and low pressure 7 turbines. The gases finally escape through a nozzle whose section allows the acceleration of these gases to generate propulsion. The fan 2 is rotatable around the longitudinal axis X. The fan 2 comprises blades 2a regularly distributed around a disc centered on the longitudinal axis X. The turbomachine 1 further comprises a nacelle 8 arranged around the engine. The nacelle 8 is annular and centered on the longitudinal axis X. It comprises, from upstream to downstream, an air inlet section 9, an engine section 10 and a rear section 11. The air inlet, engine and rear sections 9, 10, 11 are annular and centered on the longitudinal axis X. The air inlet section 9 comprises an outer wall 9a, an inner wall 9b and an air inlet lip 9c connecting the outer and inner walls 9a, 9b at their upstream ends. The outer and inner walls 9a, 9b radially delimit an inlet compartment 17. The engine section 10 comprises a cowling comprising an annular outer panel 10a centered on the longitudinal axis X. The outer panel 10a is advantageously formed of two half panels movable in rotation relative to each other around an axis of rotation extending longitudinally. This allows the opening and closing of the outer panel 10a. For example, with reference to |Fig.2], the half panels are mounted movable in rotation around a mast 20. The mast 20 makes it possible to connect the turbomachine 1 to the aircraft 1. The outer panel 10a comprises a first composite material. It comprises a polymer matrix and reinforcing fibers embedded in the matrix. The polymer matrix is ​​for example chosen from thermosetting polymers such as an epoxy resin or thermoplastic polymers such as a polyolefin. The outer panel 10a is advantageously produced by draping, in particular by draping prepregs, in particular under vacuum. The outer panel 10a has an outer face 12a and an inner face 12b. The outer and inner faces 12a, 12b each have a surface condition. The surface condition of the outer face 12a is different from the surface condition of the inner face 12b. Each external and internal face 12a, 12b has a roughness R and a waviness W. The surface condition is defined in the standard 1ISO4287:1997 or the standard ASME B46.1:2009. The surface condition is characterized in particular by two main parameters which are the roughness R and the waviness W. Roughness R (also called "roughness" in English) corresponds to small geometric irregularities, of the order of jm, unlike undulation W (also called "waviness" in English) which corresponds to large geometric irregularities, of the order of mm, and generally periodic. Roughness Ra is the arithmetic mean of the absolute values ​​of the ordinates of the surface roughness profile within a base length of the profile. Roughness Ra is defined in ISO4287:1997. It can be measured according to ISO 4288:1996 or ASME B46.1:2009. The waviness Wa is the arithmetic mean of the absolute values ​​of the ordinates of the surface waviness profile within a base length of the profile. The waviness Wa is defined in ISO4287:1997. It can be measured according to ISO 4288:1996 or ASME B46.1:2009. The surface condition of the outer face 12a is superior, that is to say better, than the surface condition of the inner face 12b. The roughness R of the external face 12a is less than the roughness R of the internal face 12b. Preferably, the roughness Ra of the external face 12a is less than the roughness Ra of the internal face 12b. Furthermore, the undulation W of the external face 12a is less than the undulation W of the internal face 12b. Preferably, the undulation Wa of the external face 12a is less than the undulation Wa of the internal face 12b. The external face 12a is in contact with the air and a good surface condition of this face makes it possible to reduce disturbances to the air flow along the turbomachine 1. Such a configuration therefore makes it possible to maximize the aerodynamic performance of the turbomachine 1 and consequently, of the aircraft. The roughness Ra of the external face 12a is for example less than 6.4 um, less than 3.2 um, less than 0.8 um. The roughness Ra of the internal face 12b is for example greater than 3.2 um, in particular greater than 6.4 um. The undulation Wa of the external face 12a is for example less than or equal to 0.8 mm and the undulation Wa of the internal face 12b is for example greater than 0.8 mm. The engine section 10 further comprises a casing 16 arranged inside the cowling. The casing 16 surrounds the engine. The casing 16 is annular and centered on the longitudinal axis X. The casing 16 comprises, for example, a fan casing 16a surrounding the fan 2 and a motor casing 16b surrounding the gas generator and located downstream of the fan casing 16a. The fan and motor casings 16a, 16b are, for example, axially connected via first annular flanges 16c. The casing 16 is connected to the air inlet section 9 and to the rear section 11 by second annular flanges 16c°. The casing 16 and the outer panel 10a radially delimit a compartment engine 18. The rear section 11 comprises an annular shell comprising outer and inner walls 11a, 11b. The outer and inner walls 11a, 11b delimit between them a rear compartment 19. The nacelle 8 further comprises an annular upstream partition 9d. Preferably, the upstream partition 9d is a fire- and fluid-tight partition. It axially separates the inlet compartment 17 and the engine compartment 18. The upstream partition 9d extends radially between the outer and inner walls 9a, 9b. The upstream partition 9d is, for example, made of metal, such as titanium. The nacelle 8 further comprises an annular downstream partition 11c. The downstream partition 11c extends radially between the outer and inner walls 11a, 11b. It axially separates the engine compartment 18 from the rear compartment 19. Preferably, the annular partition 11c is a fire- and fluid-tight partition. The downstream partition 11c is connected to a downstream angle iron 15 and the upstream partition 9d is connected to an upstream angle iron 15'. The downstream and upstream angles 15, 15° are annular. The downstream and upstream angles 15, 15° are arranged inside the outer panel 10a. They each have an L-shaped cross-section. They each comprise an axial wing 15a and a radial wing 15b. The axial wing 15a of the downstream angle iron 15 extends into the rear compartment 19 and the radial wing 15b of the downstream angle iron 15 is connected to the annular partition 11c or rests against the annular partition 11c. It extends radially inwards from the axial wing 15a. In order to improve the sealing of the engine compartment 18 and to isolate it at least from the rear compartment 19, the hood further comprises at least one annular seal 14. The seal 14 is arranged radially between the downstream angle iron 15 and the outer panel 10a. The seal 14 is more particularly arranged radially between the outer panel 10a and the axial wing 15a. The seal 14 is made of a material comprising an elastomer such as a silicone. Advantageously, the material further comprises reinforcing fibers embedded in the elastomer. The reinforcing fibers are, for example, glass fibers. The cover further comprises a seal track 13 arranged radially between the seal 14 and the outer panel 10a. The joint track 13 comprises external and internal faces 13a, 13b. The external face 13a is glued to the internal face 12b of the outer panel 10a and the joint 14 rests on the internal face 13b. The material of the glue is for example chosen from epoxy resins. Each external and internal face 13a, 13b has a surface condition. Preferably, the surface condition of the external face 13a is different from the surface condition of the internal face 13b. Each external and internal face 13a, 13b has a roughness R and a waviness W. The surface condition of the inner face 13b of the joint track 13 is superior, that is to say better, than the surface condition of the inner face 12b of the outer panel 10a. The roughness R of the inner face 13b of the joint track 13 is less than the roughness R of the inner face 12b of the outer panel 10a. Preferably, the roughness Ra of the inner face 13b of the joint track 13 is less than the roughness Ra of the inner face 12b of the outer panel 10a. The corrugation W of the inner face 13b of the joint track 13 is less than the corrugation W of the inner face 12b of the outer panel 10a. Preferably, the corrugation Wa of the inner face 13b of the joint track 13 is less than the corrugation Wa of the inner face 12b of the outer panel 10a. Thanks to this characteristic, the seal 14 rests on a surface having a better surface condition than that of the internal face 12b of the external panel 10a. This makes it possible to improve the sealing of the cover. The surface condition of the inner face 13b of the joint track 13 is superior, that is to say better, than the surface condition of the outer face 13a of the joint track 13. The roughness R of the inner face 13b of the joint track 13 is less than the roughness R of the outer face 13a of the joint track 13. Preferably, the roughness Ra of the inner face 13b of the joint track 13 is less than the roughness Ra of the outer face 13a of the joint track 13. The undulation W of the inner face 13b of the joint track 13 is less than the undulation W of the outer face 13a of the joint track 13. Preferably, the undulation Wa of the inner face 13b of the joint track 13 is less than the undulation Wa of the outer face 13a of the joint track 13. Such a characteristic makes it particularly advantageous to promote the bonding of the joint track 13 to the outer panel 10a. Indeed, the bonding faces are the faces having the poorest surface conditions, therefore the greatest roughness and undulation, which promotes bonding and therefore improves the bonding strength of these two parts. The roughness Ra of the inner face 13b of the joint track 13 is less than or equal to 8 Hm, less than or equal to 6.5 um, less than or equal to 6.4 um, less than or equal to 4 jm, less than or equal to 3.5 um, less than or equal to 3.2 um, less than or equal to 0.8 um. The undulation Wa of the inner face 13b of the joint track 13 is less than or equal to 0.8 mm. The roughness Ra of the outer face 13a of the joint track 13 is greater than 3.2um, 5, greater than 6um, greater than 6.4um. The undulation Wa of the inner face 13b of the joint track 13 is greater than 0.8 mm. The joint track 13 has a thickness e of between 0.1 mm and 10 mm, advantageously between 0.1 mm and 6 mm. The joint track 13 advantageously has an axial length L greater than or equal to 5 mm, even more advantageously greater than or equal to 10 mm. Advantageously, the axial length L of the joint track 13 is less than an axial length of the outer panel 10a. The joint track 13 comprises a second composite material. This makes it possible to promote the bonding between the joint track 13 and the outer panel 10a and to limit the risk of the joint track 13 becoming detached due to differential expansion of the joint track 13 and the outer panel 13a. The second composite material comprises a polymer matrix and reinforcing fibers embedded in the matrix. The fibers are chosen from carbon fibers or glass fibers or aramid fibers or a mixture thereof. The polymer matrix is ​​for example chosen from thermosetting polymers such as an epoxy resin or thermoplastic polymers such as a polyolefin. The second composite material comprises at least one layer or ply 13 of fibers. Advantageously, the second composite material comprises a superposition of layers or plies 13' of fibers. Preferably, the second composite material comprises between one 13° ply and forty 13° plies. Advantageously, the first composite material is identical to the second composite material. This makes it possible to improve the connection between the joint track 13 and the outer panel 10a and to further limit the risk of the joint track 13 becoming detached due to differential expansion of the joint track 13 and the outer panel 13a. The joint track 13 is advantageously produced by draping, in particular by draping prepregs, in particular under vacuum. A second joint can be arranged radially between the upstream angle iron 15' and the outer panel 10a in the same way as described previously. The joint track 13 is produced within the draping device 100 illustrated for example in [Fig. 5]. The draping device 100 comprises a mold 102 and a bladder 104 delimiting with the mold 102 a vacuum space 104a. The pressure of the vacuum space 104a is therefore lower than the pressure outside the vacuum space 104. The draping device 100 further comprises at least one channel 106 for infusing the matrix in the unpolymerized state arranged in the vacuum space 104. The draping device 100 also advantageously comprises a non-stick strip 108 arranged in the vacuum space 104 between the channel 106 and the 13° fold. A method of manufacturing the hood will now be described with reference to [Fig.5] The process includes the following steps: (a0) manufacture the outer panel 10a, (al) manufacture the joint track 13, Then (a2) gluing the external face 13a of the joint track to the external panel 10a, in particular to the internal face 12b of the external panel 10a, then (a3) placing the seal 14 resting on the internal face 13b of the seal track 13. Step (a0) can be carried out before or after step (al). Preferably, in step (al) the joint track 13 is manufactured by draping in the draping device 100. Step (al) may include the following successive steps carried out in chronological order: - arrange at least one 13' fold in the mold 102, - arrange the infusion channel 106 in the mold 102 - arranging the bladder 104 on the mold 102 so as to delimit the vacuum space 104a between the bladder 104 and the mold 102, - inject the resin into channel 106 to form the matrix. The inner face 13b of the seal track 13 is the face facing the mold 102 and the outer face 13a is the opposite face, therefore located on the side of the bladder 104. The inner face 13b thus has a better surface condition, in particular a roughness Ra and a waviness Wa lower than the roughness Ra and the waviness Wa of the outer face 13a. The outer panel 10a can be manufactured in step (a0) according to this same method. In step (a2), the glue can be applied manually or mechanically using a gun for example. The cover of the invention therefore has good sealing, particularly against fluids and fire, while being light, inexpensive and easy to manufacture.

Claims

Claims

1. Cowl for a nacelle (8) of an aircraft turbomachine (1), the cowl extending around a longitudinal axis (X) and comprising: - an annular outer panel (10a) centered on the longitudinal axis (X) and comprising a first composite material, the outer panel (10a) comprising external and internal faces (12a, 12b) having each a surface state, - an annular seal (14), and - an annular seal track (13) arranged radially between the seal (14) and the outer panel (10a), the joint track (13) comprising faces outer and inner annular rings (13a, 13b) each having a state of surface, the surface condition of the inner face (13b) of the joint track (13) being greater than the surface condition of the internal face (12b) of the panel exterior (10a) and the seal (14) being supported on the internal face (13b) of the joint track (13), characterized in that the internal face (12b) of the outer panel (10a) is glued to the outer face (13a) of the track seal (13), and in that the seal track (13) comprises a second composite material.

2. Hood according to the preceding claim, characterized in that the state of surface of the external face (12a) of the outer panel (10a) is greater to the surface condition of the inner face (12b) of the outer panel (10a).

3. Cover according to any one of the preceding claims, ca- characterized in that the surface condition of the inner face (13b) of the track of joint (13) is greater than the surface condition of the external face (13a) of the joint track (13).

4. A hood according to any preceding claim, ca- characterized in that the external and internal faces (12a, 12b) of the panel exterior (10a) each have a roughness R, and in that the faces outer and inner annular rings (13a, 13b) of the seal track (13) each have a roughness R, the roughness R of the internal face (13b) of the joint track (13) being less than the roughness R of the internal face (12b) of the outer panel (10a).

5. Hood according to the preceding claim, characterized in that the roughness R of the external face (12a) of the outer panel (10a) is in- lower than the roughness R of the internal face (12b) of the external panel {10a).

6. Hood according to any one of claims 4 or 5, characterized in what the roughness R of the internal face (13b) of the joint track (13) is less than the roughness R of the external face (13a) of the joint track {13).

7. Hood according to any one of claims 4 to 6, characterized in that that the internal face (13b) of the joint track (13) has a roughness Ra which is less than or equal to 8 um, less than or equal to 6.5 um, in- less than or equal to 6.4 um, less than or equal to 4 um, less than or equal to 3.5 um, less than or equal to 3.2 um, less than or equal to 0.8 pm.

8. A hood according to any preceding claim, ca- characterized in that the external and internal faces (12a, 12b) of the panel exterior (10a) each have a corrugation W, and in that the outer and inner annular faces (13a, 13b) of the joint track (13) each have a W undulation, the W undulation of the internal face (13b) of the joint track (13) being less than the undulation W of the face internal (12b) of the outer panel {10a).

9. Hood according to the preceding claim, characterized in that the corrugation W of the external face (12a) of the outer panel (10a) is less than the corrugation W of the internal face (12b) of the outer panel {10a).

10. Hood according to any one of claims 8 or 9, characterized in that the corrugation W of the inner face (13b) of the joint track (13) is less than the undulation W of the external face (13a) of the track of joint (13).

11. Hood according to any one of claims 8 to 10, characterized in that the internal face (13b) of the joint track (13) has a Wa dulation which is less than or equal to 0.8 mm.

12. A hood according to any preceding claim, ca- characterized in that the second composite material comprises a matrix polymer and reinforcing fibers embedded in the matrix.

13. Hood according to the preceding claim, characterized in that the fibers are chosen from carbon fibers or glass fibers or aramid fibers or a mixture thereof.

14. Hood according to any one of claims 12 or 13, characterized in that the second composite material comprises at least one layer or a fold (13') of fibers, preferably a superposition of layers or folds (13') of fibers.

15. A hood according to any preceding claim, ca- characterized in that the joint track (13) has a thickness (e) between 0.1 mm and 10 mm.

16. A hood according to any preceding claim, ca- characterized in that it further comprises an annular compartment (15) of which an axial wing (15a) is surrounded by the seal (14), the seal (14) being arranged radially between the axial wing (15a) of the angle iron (15) and the track of seal (13).

17. Nacelle (8) for an aircraft turbomachine (1), characterized in that that it comprises a hood according to any one of the claims previous.

18. Nacelle according to the preceding claim in combination with the res- indication 16, characterized in that it comprises: - an engine section (10) comprising the hood and a casing (16) arranged at the interior of the hood, the hood and the casing (16) radially delimiting a engine compartment (18), and - a rear section (11) comprising an annular shell defining a rear compartment (19), and - a radial annular partition (11c) axially separating the com- engine compartment (18) of the rear compartment (19), the angle iron (15) being connected to the partition (11c).

19. Method of manufacturing a cover for a turbomachine nacelle (8) (1) aircraft according to any one of claims 1 to 16, ca- characterized in that it includes the following steps: (a0) manufacture the outer panel (10a), (al) manufacture the joint track (13), (a2) glue the outer face (13a) of the joint track (13) to the inner face (12b) of the outer panel (10a), then (a3) place the annular seal (14) resting on the internal face (13b) of the joint track (13).

20. Method according to the preceding claim, characterized in that in step (al) the joint track (13) is manufactured by draping.