FLOW GUIDE ASSEMBLY FOR A TURBOMACHINE

Abstract

The invention relates to a flow guide assembly (6) comprising:- two outer (62) and inner (64) annular ferrules delimiting between them a first flow vein (V2) of a flow (F2) and each being sectorized into outer and inner ferrule sectors (620, 640) arranged circumferentially around an axis (A), and- discharge conduits (66) located inside the inner ferrule (62) and opening into orifices (65) formed on this inner ferrule (62), these conduits (66) defining internal passages for discharge flow (F3) intended to be injected into the first vein (V2) through these orifices (65), in which each of the conduits (66) is formed from a single piece of composite material with one of the sectors of the inner ferrule (640) which comprises the orifice (65) into which this conduit (66) opens. Figure for abstract: Figure 7

Description

Title of the invention: FLOW GUIDE ASSEMBLY FOR A TURBOMACHINE Technical field

[0001] The invention relates to the field of turbomachines, in particular dual-flow turbomachines for aircraft. It relates in particular to a flow guide assembly for a turbomachine, making it possible, for example, to guide one or more flows in a vein of the turbomachine. It also relates to a turbomachine comprising such a flow guide assembly. Technical background

[0002] A dual-flow turbomachine, in particular for an aircraft, generally comprises a fan and a gas generator (or engine). The gas generator comprises, from upstream to downstream depending on the flow of gases in the turbomachine, at least one compressor, a combustion chamber and at least one turbine. This gas generator can be installed in an inner casing also called an inter-stream casing (or intermediate casing). The fan is arranged upstream of the gas generator and in an outer casing. The air passing through the turbomachine is divided into a primary flow (or hot air flow) circulating in the gas generator and a secondary flow (or cold air flow) from the fan circulating around the inter-stream casing.

[0003] The dual-flow turbomachine comprises a primary duct in which the primary flow circulates and a secondary duct which extends around the primary duct and in which the secondary flow circulates. The primary and secondary ducts are separated by the inter-flow casing.

[0004] The turbomachine is also equipped with a flow guidance system or assembly, known by the English acronym "engine kit". This guidance assembly makes it possible to guide the secondary flow and / or a so-called discharge flow coming in particular from the compressor, in the secondary duct of the turbomachine. For this, this guidance assembly comprises a discharge duct (or valve) known by the English designation "Variable Bleed Valve" (abbreviated VBV) or "Handling Bleed Valve" (abbreviated HBV). This discharge duct is located in the inter-vein casing and makes it possible to take a portion of the primary flow compressed by the compressor, in particular to discharge the high-pressure compressor, and to eject it into the secondary flow of the secondary duct with which it mixes. This discharge aims to stabilize the operation of the compressor by limiting the phenomena of pumping, rotating separation or floating.

[0005] Figures 1 and 2 illustrate an example of such a flow guide assembly 6 which may comprise: - two outer 62 and inner 64 annular shells extending around each other and around the same axis A, these two shells 62, 64 delimiting between them a first flow vein V2 of a first flow F2 (such as the secondary flow in the turbomachine), these shells 62, 64 being sectorized and each comprising shell sectors 620, 640 arranged circumferentially end to end around the axis A, - connecting arms 68 of the ferrules 62, 64 between them, which extend radially between the ferrules 62, 64 and which are connected to these ferrules 62, 64, these arms 68 being tubular and capable of being crossed by easements intended to pass through the first flow vein V2, and - discharge conduits 66 which are located inside the internal shell 64 and which open into orifices 65 formed on this internal shell 64, these discharge conduits 66 defining internal passages of discharge flow F3 intended to be injected into the first flow vein V2 through these orifices 65.

[0006] This guide assembly 6 makes it possible to perform the following functions: - guiding a tertiary flow (such as the discharge flow), which is formed by the primary flow entering the discharge conduit, to the secondary conduit (such as the first flow vein of the guide assembly), - ensure the aerodynamic continuity of the tertiary flow, - guide and ensure the continuity of primary flow entering the guide assembly and exiting into the discharge conduits, - ensure the passage and maintenance of services (for example electrical, mechanical, hydraulic, air / oil exchanger) between the gas generator and an external casing (or a nacelle) surrounding this gas generator, - ensure the mechanical connection between the gas generator and the nacelle, - ensure fire protection between the different compartments of the gas generator and the secondary conduit, and - allow accessibility to equipment and services for maintenance.

[0007] The guide assembly 6 comprises discharge fins (or grids) 666 fixed in each of the orifices 65 of the internal shell sectors 640. These discharge fins 666 make it possible to straighten the discharge flow in the secondary duct, and to prevent any external body from entering the primary duct via this discharge duct 66. The internal shell sectors 640, the discharge ducts 66 and the discharge fins 666 are connected to each other by bolt-type fasteners.

[0008] The guide assembly 6 also comprises sealing elements 7 which are fixed between the internal shell sectors 640 and the discharge conduits 66 to provide sealing and protection against fire and air.

[0009] Conventionally, the guide assembly 6 comprises eight discharge ducts 66, eight fins 666 and at least eight sealing elements 7 which are distributed circumferentially on the internal shell 64. This arrangement can be cumbersome for the turbomachine, and can also complicate the production and assembly of the guide assembly (such as the use of specific tooling - for example an assembly pin, tooling for positioning the discharge ducts relative to the shell sectors, etc.). This can disrupt and impact the operation of the flow guide assembly and thus generally disrupt the operation of the turbomachine.

[0010] In this context, it is interesting to propose a solution making it possible to overcome at least one of the aforementioned drawbacks, in particular by optimizing and simplifying the production, assembly and maintenance of a flow guide assembly in a turbomachine, while being light and less bulky. Summary of the invention

[0011] The present invention provides a simple, effective and economical solution to the aforementioned drawbacks of the prior art.

[0012] To this end, the invention relates to a flow guide assembly for a turbomachine, in particular an aircraft turbomachine, the assembly comprising: - two annular ferrules, respectively external and internal, which extend around each other and around the same axis A, these external and internal ferrules delimiting between them a first flow vein of a flow, the ferrules being sectorized and each comprising external and internal ferrule sectors arranged circumferentially end to end around said axis A, and - discharge conduits which are located inside the internal shell and which open into orifices formed on this internal shell, these discharge conduits defining internal passages for discharge flows intended to be injected into said first vein through these orifices.

[0013] According to the invention, each of the discharge conduits is formed from a single piece of composite material with one of the sectors of the internal shell, this internal shell sector comprising the orifice into which this discharge conduit opens.

[0014] The expression "one piece" means that each discharge conduit and the associated internal shell sector are one-piece and made from a single piece with a single material (namely composite material).

[0015] Such a configuration of the invention makes it possible to simplify and facilitate the design of the flow guiding assembly to improve the flow guiding performance (such as the flow of the first flow vein and / or the discharge flow) in the first flow vein of this guiding assembly. This makes it possible to guarantee improved life of the guide assembly.

[0016] Indeed, the one-piece construction makes it possible to form surfaces of the discharge duct and the internal shell sector which are continuous, uniform and homogeneous in composite material to reinforce the mechanical and fire resistance of the guide assembly. In this way, the use of bolt-type fasteners or sealing elements of the prior art is no longer necessary to assemble the discharge duct to the internal shell sector in order to form the guide assembly. Thus, the one-piece design therefore makes it possible to optimize the size and mass of this guide assembly. In this way, the discharge ducts and the internal shell sectors can be sized as required for a minimum mass while retaining the flow guidance and fire protection resistance functions.

[0017] Furthermore, the composite material (such as organic matrix CMO or ceramic CMC) allows the guide assembly to withstand temperatures ranging from 100°C to 1400°C (more specifically from 100°C to 250°C for CMO and from 600°C to 1400°C for CMC). The use of composite materials also contributes to optimizing the performance of the guide assembly and generally of the turbomachine, in particular by reducing the overall mass of the turbomachine, thus reducing fuel consumption which in turn leads to a reduction in harmful emissions (CO, CO2, Nox, etc.). Thus, the present invention makes it possible to contribute significantly to limiting environmental impacts.

[0018] The invention therefore has the advantage of being based on a design that is simple to produce and repair, offering very high reliability, and is not very penalizing in terms of cost, mass and size.

[0019] The flow guide assembly according to the invention may comprise one or more of the following features, taken in isolation from one another or in combination with one another:

[0020] — the flow guide assembly comprises connecting arms of the outer ferrules and internal between them, which extend radially between the external and internal ferrules and which are connected to these external and internal ferrules, these arms being tubular and capable of being crossed by easements intended to pass through said first vein;

[0021] - each internal shell sector extends axially between upstream and downstream edges which extend at least partly radially towards the interior of said sector, the orifice into which the discharge conduit opens being located between these upstream and downstream edges;

[0022] - at least one of the upstream and downstream edges has an L-shape in axial section and comprises a radial wall connected to a cylindrical wall which forms a free end of the internal shell sector;

[0023] - flow guide assembly further comprises: - at least one seal applied against the upstream edge of the internal shell sector, and in particular against the cylindrical wall of this internal shell sector, and / or - a heat exchanger is applied against the downstream edge of the internal shell sector, and in particular against the cylindrical wall of this internal shell sector;

[0024] - each internal shell sector comprises a rib projecting radially towards the interior at its downstream edge, for example at its radial wall, and located between the orifice and the downstream edge;

[0025] - each internal shell sector has an excess thickness at the level of at least one upstream and downstream edges;

[0026] - each discharge conduit is tubular and comprises an elongation axis B along its internal passage which is inclined relative to the sector of the internal shell;

[0027] - each discharge conduit is connected to the shell by curved or elbow connections which each have a thickness identical to a minimum thickness of said discharge duct and / or a minimum thickness of the internal shell sector;

[0028] - flow guide assembly further comprises attached discharge fins or formed in each of the orifices of the internal ferrule sectors;

[0029] — the thickness of the bond is at least 1.65 mm;

[0030] — each discharge conduit is inclined at an angle a of, for example, between 20° and 70° relative to the sector of the internal shell;

[0031] — the composite material has an organic or ceramic matrix;

[0032] — the composite material comprises a fibrous preform embedded in a resin, the fibrous preform being woven or laminated in multilayers;

[0033] — the composite material comprises fibers chosen from carbon fibers, of glass, aramid and polyamide, or a mixture of at least two of these fibers.

[0034] The present invention also relates to a turbomachine, in particular for an aircraft, comprising a flow guidance assembly according to one of the particular features of the invention.

[0035] Each discharge duct may comprise a first end opening into the first flow vein of the flow through the orifice, and a second end opposite the first radial end and opening into a second flow vein of another flow of the turbomachine, in particular between a low pressure compressor and a high pressure compressor of this turbomachine.

[0036] The turbomachine may be a turbojet, turboprop or aircraft turboshaft engine.

[0037] The present invention may also relate to a method of manufacturing a flow guide assembly according to one of the particularities.

[0038] The method may comprise the following steps: (a) provide a so-called negative mold comprising an impression, (b) forming a fibrous preform in the mold cavity, (c) compacting the fiber preform, (d) consolidating (or densifying) the fiber preform with a polymerization resin to form each discharge conduit in one piece with one of the internal shell sectors, (e) demolding the part obtained in step (d), and (f) provide the outer ferrule. Brief description of the figures

[0039] The present invention will be better understood and other details, characteristics and advantages of the present invention will appear more clearly on reading the description of a non-limiting example which follows, with reference to the appended drawings in which:

[0040] [Fig.l] is a perspective view schematically representing a flow guide assembly for a turbomachine according to the prior art;

[0041] [Fig.2] is an axial sectional view of a discharge duct and an associated inner shell sector of the guide assembly of [Fig.l];

[0042] [Fig. 3] is a schematic half-view in axial section of a turbomachine according to the invention;

[0043] [Fig.4] is a schematic half-view in axial section and enlarged of a part of a guide assembly according to the invention in the turbomachine of [Fig.3];

[0044] [Fig.5] is a perspective and sectional view of the discharge duct and the corresponding internal shell sector of the guide assembly of [Fig.3] or 4;

[0045] [Fig.6] is a perspective view of the discharge duct and the corresponding internal shell sector of the guide assembly of [Fig.4] or 5;

[0046] [Fig.7] is a half axial sectional view of the discharge duct and the one-piece internal shell sector of the guide assembly of [Fig.5] or 6;

[0047] [Fig.8] is a block diagram of a method of manufacturing the flow guide assembly of the invention.

[0048] Elements having the same functions in different implementations have the same references in the figures. Detailed description of the invention

[0049] By convention, in the description below, the terms “longitudinal” and “axial” describe the orientation of structural elements extending in the direction of a longitudinal axis (such as a turbomachine). The terms “radial” or “vertical” describe an orientation of structural elements extending in a direction perpendicular to the longitudinal axis. The terms “inner” and “outer”, and “internal” and “external” are used with reference to a positioning relative to the longitudinal axis. Thus, a structural element extending along the longitudinal axis has an inner face facing the longitudinal axis and an outer surface, opposite its inner surface. Similarly, the terms "upstream" and "downstream" are defined in relation to the direction of gas flow in the turbomachine.

[0050] Figures 1 and 2 have been described in the technical background of the present application and represent a flow guide assembly for a turbomachine according to the prior art.

[0051] The invention can be applied in a non-limiting manner to a turbomachine 10, in particular an aircraft turbomachine. The turbomachine 10 can be a turbojet, turboprop or turboshaft engine.

[0052] The turbomachine 10 can extend along a longitudinal axis X.

[0053] Figures 3 and 4 illustrate an example of the turbomachine 10, called a double-flow turbomachine. This turbomachine 10 may comprise a primary duct C1 and a secondary duct C2 which extends around the primary duct C1. The primary ducts C1 and secondary ducts C2 are separated by an annular casing called an inter-stream 4 (or intermediate casing).

[0054] With reference to [Fig.4], the inter-vein casing 4 may comprise two inner 42 and outer 44 annular portions extending around each other.

[0055] The turbomachine 10 may conventionally comprise, from upstream to downstream in the direction of flow of the gases F along the longitudinal axis X, a fan 1 and an engine 2 (or gas generator).

[0056] The fan 1 of [Fig. 3] is shrouded. For this purpose, an annular external casing 5, in particular of a nacelle, can extend around the fan 1 and a rectifier 3 of the turbomachine 10.

[0057] The blower 1 allows the suction of an initial flow entering the turbomachine 10 which is divided into a primary flow F1 (called hot air flow) and a secondary flow F2 (called cold air flow). The primary flow F1 passes through the primary duct C1 of the turbomachine 10 while the secondary flow F2 is directed towards the secondary duct C2.

[0058] The rectifier 3 may comprise at least one annular row of vanes (in particular stator or fixed) called rectifier or outlet guide vanes (designated by the English term “Outlet Guide Vanes” OGV). These OGV vanes make it possible to straighten the secondary flow at the outlet of the fan 1 located upstream in order to provide maximum thrust at the outlet of the turbomachine 10.

[0059] The engine 2 may typically comprise a low pressure compressor 2a, a high pressure compressor 2b, a combustion chamber 2c, a high pressure turbine 2e, a low pressure turbine 2f and possibly a gas exhaust nozzle (not shown in [Fig.3]).

[0060] The primary flow Fl is compressed within the low pressure compressor 2a then the high-pressure compressor 2b. This compressed air flow is then mixed with fuel and burned in the combustion chamber 2c. The gases formed by the combustion pass through the high-pressure turbine 2d and the low-pressure turbine 2e. The gases can finally escape through the nozzle, the cross-section of which allows the acceleration of these gases to generate propulsion. The secondary flow F2 passes through the rectifier 3, which accelerates the circulation speed of the secondary flow F2 to generate propulsion.

[0061] With reference to figures 3 to 7, the turbomachine 10 may comprise a flow guide assembly 6, comprising: - two annular ferrules, respectively, external 62 and internal 64, and - discharge conduits 66 which are located inside the internal shell 64 and which open into orifices 65 formed on this internal shell 64.

[0062] In operation in the turbomachine 10, this guide assembly 6 can be arranged between the low pressure 2a and high pressure 2b compressors, as illustrated in FIGS. 3 and 4. This allows the guide assembly 6 to take the primary flow F1 coming from the primary duct C1 to generate a discharge flow F3 (also designated as tertiary flow) which is injected / discharged by the discharge ducts 66 into the secondary duct C2 and mixes with the secondary flow F2.

[0063] The outer 62 and inner 64 annular shells (hereinafter referred to as outer shell 62 and inner shell 64) extend around each other and around the same axis A. This axis A may correspond substantially to the longitudinal axis X of the turbomachine 10.

[0064] The outer 62 and inner 64 shells delimit between them a first flow vein V2 of a flow F2. This first flow vein V2 can correspond to at least a portion of the secondary duct C2 and the flow F2 can correspond to the secondary flow of the turbomachine 10 when the guide assembly 6 is mounted in this turbomachine.

[0065] The outer 62 and inner 64 ferrules are sectorized and each comprise outer 620 and inner 640 ferrule sectors arranged circumferentially end to end around the axis A. By way of example, the inner ferrule 64 may comprise between four and ten inner ferrule sectors 640.

[0066] The flow guide assembly 6 may comprise connecting arms 68 of the outer and inner ferrules 62, 64 between them.

[0067] The connecting arms 68 (hereinafter referred to as arms 68) extend radially (relative to the axis A) between the outer 62 and inner 64 ferrules and are connected to these outer 62 and inner 64 ferrules. These arms 68 are tubular and capable of being crossed by services intended to pass through the first flow vein V2.

[0068] The discharge conduits 66 define internal passages 660 for flow of discharge F3 intended to be injected into the first flow vein V2 through these orifices 65.

[0069] As illustrated in Figures 4 and 7, each discharge duct 66 can open, on the one hand, into the first flow vein V2 of the flow F2 through the orifice 65, and on the other hand, into a second flow vein VI of another flow F1 of the turbomachine 10. In particular, the second flow vein VI is between the low-pressure compressor 2a and the high-pressure compressor 2b of the turbomachine 10. This second flow vein VI can correspond to at least a portion of the primary duct C1 and the other flow F1 can correspond to the primary flow F1 when the guide assembly 6 is mounted in the turbomachine 10.

[0070] One of the particularities of the invention is that each of the discharge conduits 66 is formed from a single piece of composite material with one of the sectors of the internal shell 640, and this internal shell sector 640 comprising the orifice 65 into which this discharge conduit 66 opens. As mentioned above, this configuration makes it possible in particular to simplify the design of the flow guide assembly by reducing the mass and the size, while retaining the functions of flow guide, mechanical strength and fire protection. An example of the discharge conduit 66 and the internal shell sector 640 formed from a single piece (or otherwise said to be a single block) is illustrated in a non-limiting manner in FIGS. 5, 6 and 7.

[0071] Each internal shell sector 640 may have a first minimum thickness E640. This first minimum thickness E640 is measured relative to a plane perpendicular to the axis A. The first minimum thickness E640 may be at least 1.65 mm. This provides fire protection or, in other words, forms a fire barrier.

[0072] Each internal shell sector 640 may extend axially between upstream 642 and downstream 644 rims which extend at least partly radially inward (relative to the axis A) of this internal shell sector 640. The orifice 65 into which the discharge conduit 66 opens may be located between these upstream 642 and downstream 644 rims. The upstream rim 642 in particular allows the external casing 5 to be positioned on this internal shell sector 640 (and therefore on the flow guide assembly 6). The downstream rim 644 in particular allows a heat exchanger 9 to be positioned on the internal shell sector 640.

[0073] At least one of the upstream 642 and downstream 644 rims may have an L-shape in axial section and may comprise a radial wall 642a, 644a connected to a cylindrical wall 642b, 644b which forms a free end of this internal shell sector 640.

[0074] The upstream rim 642 may have a second thickness E642 measured along a plane perpendicular to the axis A. This second thickness may be greater than or identical to the first minimum thickness EM0-

[0075] The downstream edge 644 may have a third thickness E644 measured along a plane perpendicular to the axis A. This third thickness can be greater than or identical to the first minimum thickness EM0- The third thickness E644 can be identical to the second thickness E642.

[0076] In the example of [Fig.7], the internal shell sector 640 has an excess thickness E642, E644 at at least one of the upstream 642 and downstream 644 edges. In other words, one of the second and third thicknesses E642, E644 may be greater than the first minimum thickness E640. This excess thickness E642, E644 makes it possible to form a rigid support zone at the upstream 642 and downstream 644 edges in particular to support the positioning and support, respectively, of the seal 8 and the heat exchanger 9.

[0077] The guide assembly 6 may further comprise: - at least one seal 8 applied against the upstream rim 642, and in particular against the cylindrical wall 642b, and / or - the heat exchanger 9 applied against the downstream rim 644, and in particular against the cylindrical wall 644b.

[0078] The seal 8 provides a fluid and fire seal between the guide assembly 6 and the external casing 5 (or the nacelle) which can be mounted to rest on the upstream rim 642.

[0079] Each internal shell sector 640 may comprise a rib 646 projecting radially inwards (relative to the axis A). This rib 646 is located at the downstream rim 644, and for example at the radial wall 644a. In particular, the rib 646 is located between the orifice 65 and the downstream rim 644 in the example of [Fig.7]. The rib 646 is configured to ensure mechanical rigidity of the internal shell sector 640 and to improve the mounting space between the internal shell 640 and the heat exchanger 9.

[0080] Each internal shell sector 640 may comprise a shoulder 648 projecting radially inwards (relative to the axis A). This shoulder 648 is located at the upstream rim 642, and for example at the radial wall 642a. In particular, the shoulder 648 is located between the orifice 65 and the upstream rim 642 in the example of [Fig.7]. The shoulder 648 makes it possible to form the excess thickness of the second thickness E642 at the upstream rim 642.

[0081] Each discharge conduit 66 may be tubular. The discharge conduit 66 may comprise a first end 662 and a second end 664 opposite the first end 662. The first end 662 opens into the first flow vein V2 of the flow F2. The second end 664 may open into the second vein VI of the other flow FL.

[0082] As illustrated in Figures 4 and 7, the first end 662 can open into the first vein V2 through the orifice 65 (called the discharge or outlet orifice for the discharge flow F3), and the second end 664 can open into the second vein VI through a hole 67 (called the inlet orifice for the discharge flow F3) formed in particular on a downstream flange 48 of the inter-vein casing 4.

[0083] In the example of [Fig.4], the inter-vein casing 4 may comprise an intermediate space 40 intended to receive the other flow F1 coming in particular from the low pressure compressor 2a. This intermediate space 40 can be delimited from upstream to downstream by an upstream flange 46 and the downstream flange 48 of the inter-flow casing 4. These upstream 46 and downstream 48 flanges can connect the inner 42 and outer 44 annular portions together and thus delimit the intermediate space 40. The inner annular portion 42 can comprise an opening 47 intended to be selectively opened or closed by a tab 470 depending on the flight phases of the turbomachine 10. Preferably, the tab 470 can be movable between a closed position, in which the tab 470 closes the opening 47, and an open position, in which the tab 470 releases the opening 47 so as to allow the other flow F1 to pass into the intermediate space 40.This other flow Fl entering the intermediate space 40 can generate and form the discharge flow F3 which passes into the discharge conduit 66 through the hole 67 to open into the first vein VI and mix in the flow F2 through the orifice 65.

[0084] The discharge conduit 66 may comprise an elongation axis B along its internal passage 660 which may be inclined relative to the corresponding sector of the internal shell 640. For example, the discharge conduit 66 may be inclined at an angle a of between 20° and 70° relative to a plane passing through the internal shell sector 640.

[0085] Each discharge conduit 66 may have a fourth minimum thickness E66 measured in particular along a plane inclined relative to the axis A. The first E6540 and fourth E66 minimum thicknesses may be identical.

[0086] Each discharge duct 66 may be connected to the internal shell sector 640 by curved or elbowed connections 665. These connections 665 may each have a fifth thickness E655 measured in particular along a plane inclined relative to the axis A. The fifth thickness E655 may be identical to the first minimum thickness E640 of the internal shell sector 640 and / or the fourth minimum thickness E66 of the discharge duct 66. For example, the fifth thickness E665 may be at least 1.65 mm. This provides fire protection or, in other words, forms a fire barrier.

[0087] The composite material forming the internal shell sectors 640 and the discharge conduits 66 may comprise a fibrous preform embedded in a resin. This fibrous preform may be woven (for example in three dimensions) or laminated in multilayers.

[0088] The composite material (or the fiber preform) may comprise fibers chosen from carbon, glass, aramid and polyamide fibers, or a mixture of at least two of these. least two of these fibers.

[0089] The resin may be a thermoset or a thermoplastic. For example, the resin may be based on epoxy, polyepoxide, polyimide, polybismaleimide, polyurethane, polyester or vinylester.

[0090] The guide assembly 6 may further comprise discharge fins 666 added or formed in each of the orifices 65 of the internal shell sectors 640. For example, each of the orifices 65 may comprise between two and six discharge fins 666. These discharge fins 666 may be made of composite material, in particular by thermoforming (such as by stamping). These exchange fins 666 may then be mounted, for example by rivets, directly on the internal shell sector 640 and / or the discharge conduit 66.

[0091] The present application will now describe an example of a method for manufacturing the flow guide assembly 6 as described above, the successive steps of the method of which are for example summarized in [Fig.8].

[0092] The method may comprise the following steps: (a) providing a so-called negative mold comprising an imprint, (b) forming a fiber preform in the mold imprint, (c) compacting the fiber preform, (d) consolidating (or densifying) the fiber preform with a polymerization resin to form each discharge conduit 66 in one piece with one of the internal shell sectors 640, (e) demolding the part obtained in step (d), and (f) provide the outer ferrule 64.

[0093] In step (a), the imprint may be a hollow portion in which the fiber preform is formed. This hollow portion may have a shape complementary to one of the discharge conduits 66 connected to one of the internal shell sectors 640 (such as the shape illustrated in [Fig.5] or 7).

[0094] In step (b), the fiber preform may be configured to form each discharge conduit 66 in one piece with one of the inner ferrule sectors 640.

[0095] The fibrous preform can be woven (for example in three dimensions) or laminated in multilayers.

[0096] By way of example, plies of composite material may be deposited, for example by draping (or otherwise known as stacking plies) in the mold cavity to form the fiber preform.

[0097] The fibers making up the fiber preform can be chosen from carbon, glass, aramid and polyamide fibers, or a mixture of at least two of these fibers.

[0098] In step (c), the assembly (namely the fiber preform obtained in step (b) and the mold) can be placed in a vacuum tank to achieve compaction, particularly in an autoclave. Compacting the fiber preform ensures a good volume ratio of the fibers in the fiber preform during polymerization.

[0099] In step (d), the fiber preform may be consolidated by heating in the autoclave in order to polymerize the resin.

[0100] The resin may be a thermoset or a thermoplastic. For example, the resin may be based on epoxy, polyepoxide, polyimide, polybismaleimide, polyurethane, polyester or vinylester.

[0101] Steps (a) to (d) may be repeated several times so as to obtain the necessary number of discharge conduits 66 and internal shell sectors 640 forming the guide assembly 6.

[0102] In step (e), demolding can be carried out after cooling of the part obtained in step (d).

[0103] In an alternative embodiment of the method, it may comprise an additional step between steps (e) and (f) which consists of adding the upstream 642 and downstream 644 flanges to the internal shell sector 640 of the part obtained in step (e). This addition of the upstream 642 and downstream 644 flanges may be carried out by machining, in particular when these upstream 642 and downstream 644 flanges are made of metallic material.

[0104] In step (f), connecting arms 68 may also be provided to assemble the connecting arms 68 between the outer 64 and inner 62 ferrules.

[0105] The outer ferrule 62 may be made of composite material. The connecting arms 68 may be made of metallic material (such as titanium), in particular by casting.

[0106] In the preceding description, the invention is described in the context of its application to the aircraft dual-flow turbomachine 10, in particular with reference to FIGS. 3 to 7. The invention can be applied generally to other types of turbomachine comprising such a flow guide assembly 6.

[0107] The flow guide assembly according to the invention provides several advantages which are in particular: - simplify the design and integration of the discharge ducts with the internal shell sectors to reduce the cost and improve the manufacturing of this guide assembly, - simplify assembly and assembly time, in particular to avoid the use of specific tools (such as an assembly gauge, positioning tool, etc.), - limit the number of connecting parts, such as bolt fasteners, joints, etc., - ensure an optimal connection between the discharge ducts and the internal shell sectors, - optimize the life of the guide assembly, and - easily adapt to existing turbomachine gas generators.

[0108] Overall, this proposed solution is simple, efficient and economical to produce and assemble in a turbomachine, while ensuring optimal and homogeneous flow guidance within this turbomachine.

Claims

Claims

1. Flow guide assembly (6) for a turbomachine (10), in particular an aircraft one, the assembly (6) comprising: - two annular shells, respectively external (62) and internal (64) which extend around each other and around the same axis (A), these external and internal shells (62, 64) delimiting between them a first flow vein (V2) of a flow (F2), the external and internal shells (62, 64) being sectorized and each comprising external and internal shell sectors (620, 640) arranged circumferentially end to end around said axis (A), - discharge ducts (66) which are located inside the internal shell (62) and which open into orifices (65) formed on this internal shell (62), these discharge ducts (66) defining internal passages (660) of discharge flow (F3) intended to be injected into said first vein (V2) through these orifices (65),characterized in that each of the discharge conduits (66) is formed from a single piece of composite material with one of the sectors of the internal shell (640), this sector of internal shell (640) comprising the orifice (65) into which this discharge conduit (66) opens.,

2. Flow guide assembly according to claim 1, characterized in that each internal ferrule sector (640) extends axially between upstream and downstream rims (642, 644) which extend at least partly radially towards the inside of said sector (640), the orifice (65) into which the discharge conduit (66) opens being located between these upstream and downstream rims (642, 644).

3. Flow guide assembly according to claim 2, characterized in that at least one of the upstream and downstream rims (642, 644) has an L-shape in axial section and comprises a radial wall (642a, 644a) connected to a cylindrical wall (642b, 644b) which forms a free end of the internal shell sector (640).

4. Flow guide assembly according to claim 2 or 3, characterized in that it further comprises: - at least one seal (7) applied against the upstream rim (642) of the internal shell sector, and in particular against the cylindrical wall (642b) of this internal shell sector (640), and / or - a heat exchanger (8) is applied against the downstream rim (644) of the internal shell sector (640), and in particular against the cy- lindic (644b) of this internal shell sector (640).

5. Flow guide assembly according to one of claims 2 to 4, characterized in that each internal ferrule sector (640) comprises a rib (646) projecting radially inwards at its downstream rim (644), for example at its radial wall (644a), and located between the orifice (65) and the downstream rim (644).

6. Flow guide assembly according to any one of claims 2 to 5, characterized in that each internal ferrule sector (640) has an excess thickness (E^, E644) at the level of at least one of the upstream and downstream edges (642, 644).

7. Flow guide assembly according to any one of the preceding claims, characterized in that each discharge conduit (66) is tubular and comprises an elongation axis (B) along its internal passage (660) which is inclined relative to the sector of the internal shell (640).

8. Flow guide assembly according to any one of the preceding claims, characterized in that each discharge duct (66) is connected to the ferrule by curved or bent connections (665) which each have a thickness (E665) identical to a minimum thickness (E66) of said discharge duct (66) and / or a minimum thickness (E640) of the sector of the internal ferrule (640).

9. Flow guide assembly according to any one of the preceding claims, characterized in that it further comprises discharge fins (666) added or formed in each of the orifices (65) of the internal shell sectors (640).

10. Turbomachine (10), in particular for an aircraft, comprising a flow guide assembly (6) according to any one of the claims.

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