Cooling-air injection casing for cooling a rotor disc of a turbine and comprising inter-channel spaces

Abstract

The invention relates to a cooling-air injection casing (1) for cooling a rotor disc of a turbine, which casing extends about a longitudinal axis and comprises a radially outer wall (4), a downstream end wall (5) and a plurality of channels (6a, 6b) distributed about the longitudinal axis and connected to one another via the downstream end wall (5), each channel forming an air injector extending axially from an inlet port (7) opening through the radially outer wall, to an outlet port (8) opening through the downstream end wall (5), each channel being configured to guide a first air flow from an annular space for bypassing a combustion chamber to a ventilation cavity formed between the disc and a sealing flange, the channels (6a, 6b) being separated, in pairs, by an inter-channel space (11) forming a plurality of inter-channel spaces (11) arranged circumferentially about the longitudinal axis (X).

Description

Cooling air injection housing for a turbine rotor disc, including inter-channel spaces Technical Field

[0001] The present invention relates to the field of ventilation of a high-pressure turbomachine turbine and more particularly to an air injection housing for cooling a rotor disc of such a turbine. Previous technique

[0002] A turbomachine includes a high-pressure turbine which is positioned at the outlet of a combustion chamber to recover energy from the combustion gas flow and thus drive in rotation, a high-pressure compressor, located upstream of the combustion chamber and supplying the latter with pressurized air.

[0003] In the following, the terms "upstream" and "downstream" are to be taken into consideration with respect to the direction of air flow inside the high-pressure turbine, as well as inside the cooling air injection housing.

[0004] Typically, a high-pressure turbine comprises a rotor disc, positioned at the outlet of a combustion chamber and on which turbine blades are mounted, driven into rotation by a flow of gas ejected from this combustion chamber.

[0005] Due to the high temperatures reached by the combustion gases, the rotor disc and the turbine blades it supports are subjected to significant thermal stresses that can induce expansion. To limit the negative impact of these thermal stresses on the lifespan of the turbine blades, the latter are equipped with internal cooling circuits that include ducts through which ventilation air is drawn from the bottom of the combustion chamber.

[0006] This ventilation air is generally brought into an annular cavity by ventilation air injectors distributed circumferentially around the axis longitudinal of the turbomachine. The injectors are distributed around a cooling air injection housing, extend radially under the combustion chamber and are fluidly connected to an annular cavity allowing ventilation air from the bottom of the compressor to be conveyed to the turbine.

[0007] The ventilation air, exiting the injectors, enters the annular cavity located upstream of the rotor disc, passing through orifices formed in a sealing flange positioned upstream of the rotor disc. The cavity communicates with internal cooling circuits located inside the turbine blades.

[0008] Documents FR2943092 and W02023047055 describe examples of high-pressure turbines and blades.

[0009] Part of the air from the injector also circulates to an upstream purge, first passing through a downstream seal which ensures the seal between the blade and the flange at the location of an external part of the turbine.

[0010] Simultaneously, an airflow taken downstream of the last stage of the high-pressure compressor circulates through a first upstream seal and then through a second upstream seal, positioned downstream of the first upstream seal, ensuring the seal between the blade and the flange at the location of an internal part of the turbine.

[0011] Typically, the first and second upstream seals are labyrinth seals comprising flaps attached to the rotor and a ring made of abradable material connected to the housing and featuring a honeycomb structure. This airflow, drawn downstream of the last stage of the high-pressure compressor, mixes with the airflow from the injectors and then vents the upstream purge and the blades.

[0012] Airflow is injected tangentially to the longitudinal axis. The tangential velocity of the air circulating in the turbine's internal circuits is a crucial parameter for its cooling. The closer the velocity of the tangentially injected airflow is to the rotor's rotational speed, the better the cooling. Cooling. The airflow exiting the injectors has a significant tangential velocity which is equal to, or even greater than, the rotational speed of the rotor for the same radius.

[0013] However, the airflow from the first and second upstream seals has, on the contrary, a low tangential velocity and a higher temperature. This results in a decrease in the effectiveness of this airflow in cooling the upstream purge and the blades. Description of the invention

[0014] The invention therefore aims to resolve at least in part these drawbacks by proposing a cooling air injection housing for a turbine rotor disc that allows the upstream purge and blades to be cooled more efficiently.

[0015] The invention relates to a cooling air injection housing for a bladed rotor disc of a turbine, in particular a high-pressure turbine, of a turbomachine.

[0016] The casing extends around a longitudinal axis and comprises a radially external wall, a downstream end wall, and several channels distributed circumferentially around the longitudinal axis, each channel being connected on one side, upstream, to the radially external wall and, on the other side, downstream, to the downstream end wall, each channel forming an air injector extending axially from an inlet opening through the radially external wall to an outlet opening through the downstream end wall, each channel being configured to guide a first airflow from an annular bypass space of a turbine combustion chamber to a ventilation cavity formed between the rotor disc and a sealing flange positioned upstream of the rotor disc.

[0017] The canals are separated circumferentially in pairs by an inter-canal space. The canals thus delimit a plurality of inter-canal spaces arranged circumferentially around the longitudinal axis, the inter-canal spaces each separating the radially outer wall from the downstream end wall.

[0018] The invention thus provides a cooling air injection housing for a turbine rotor disc, enabling the blades to be cooled more efficiently.

[0019] The inter-channel space allows the portion of air from the second airflow to bypass the channel outlet and arrive at a high tangential velocity in the turbine purge cavity. The tangential velocity of this air portion corresponds to more than 30%, or even 50%, of the rotor speed.

[0020] The temperature of the air intended to cool the blades is reduced by approximately 15°C compared to prior art solutions as described in document W02023047055A.

[0021] Furthermore, this housing configuration eliminates an internal stiffening ring, extending circumferentially and carrying the channels, thus resulting in a mass reduction.

[0022] This solution also minimizes the air flow taken from the high-pressure compressor in order to improve the overall performance of the turbomachine.

[0023] This configuration with inter-channel spaces also allows for a lighter casing.

[0024] In some embodiments, each interchannel space extends in a general radial direction, from a radially internal inlet to a radially external outlet, each interchannel space being configured to divert a portion of a second airflow from a high-pressure compressor of the turbine and passing through the radially internal inlet and guide the portion of the second airflow from the radially external outlet to a turbine purge cavity.

[0025] In some embodiments, the channels are each delimited by two opposing circumferential end walls of the channel, a radially external channel wall and a radially internal channel wall, opposite the radially external channel wall, the circumferential end walls of the channel and the radially internal and external channel walls extending axially from the radially external wall to a downstream wall, axially opposite to the downstream end wall.

[0026] In some embodiments, each inter-channel space extends axially from the radially external wall to the downstream wall and circumferentially from a first circumferential end wall of a first channel to a second circumferential end wall of a second channel, opposite the first circumferential end wall.

[0027] In some embodiments, the housing comprises a downstream end ring delimited axially on one side, downstream, by the downstream end wall and, on the other side, upstream, by the downstream wall, and radially, on one side outwards, by a radially external ring wall and, on the other side outwards, by a radially internal ring wall, opposite the radially external ring wall, each inter-channel space being positioned between the downstream end ring and a flange extending radially towards the longitudinal axis from an upstream end of the radially external wall.

[0028] In some embodiments, the housing includes a first annular abradable element carried by a radially internal face of the radially internal wall of the crown and intended to cooperate with at least one first lip of the sealing flange to form a first sealing device.

[0029] In some embodiments, the housing includes a second annular abradable element carried by a radially external face of the radially external wall of the crown and intended to cooperate with a second lip connected to a radially external part of the sealing flange to form a second sealing device.

[0030] In some embodiments, the first and second abradable elements extend radially in projection from the downstream end wall.

[0031] In some embodiments, each channel comprises a primary section extending along the longitudinal axis from the inlet opening to a curved portion, and a secondary section extending from the curved portion to the outlet opening, the outlet opening being oriented so as to give a tangential orientation to an airflow passing through this outlet opening.

[0032] The invention also relates to a turbine for a turbomachine comprising a casing as defined above.

[0033] The aforementioned features and advantages, as well as others, will become apparent upon reading the detailed description that follows, along with examples of housing construction. This detailed description refers to the attached drawings. Brief description of the drawings

[0034] The attached drawings are schematic and are primarily intended to illustrate the principles of the presentation.

[0035] In these drawings, from one figure to another, identical elements (or parts of elements) are identified by the same reference symbols.

[0036] [Fig. 1] Figure 1 schematically represents an axial cross-sectional view of a turbomachine according to the invention;

[0037] [Fig. 2] Figure 2 schematically represents an axial cross-sectional view of part of a high-pressure turbine of the turbomachine including a cooling air injection housing, according to an embodiment of the invention;

[0038] [Fig. 3] Figure 3 schematically represents a perspective view of an angular portion of the crankcase;

[0039] [Fig. 4] Figure 4 schematically represents a view of the inside of the casing of figure 3;

[0040] [Fig. 5] Figure 5 schematically represents an external view of the housing in Figure 3. Description of the implementation methods

[0041] To make the explanation more concrete, an example of a housing 1 is described in detail below, with reference to the attached drawings. It should be noted that the invention is not limited to this example.

[0042] The invention applies to turbines 3, in particular high-pressure turbines, of a twin-spool turbomachine, such as the high-pressure turbine of an aircraft turbojet 40 shown in Figure 1. The turbojet 40 extends around a longitudinal axis X, corresponding to the axis of revolution of the turbojet 40 and the axis of rotation of the rotor.

[0043] The turbojet 40 comprises, from left to right, i.e. from upstream to downstream with reference to the gas flow during operation in the turbomachine: a fan 37, a high-pressure compressor 38, a combustion chamber 36, the high-pressure turbine 3 and a low-pressure turbine 3'. The high-pressure turbine 3 is equipped with blades 39.

[0044] As is known, the high-pressure turbine 3 is positioned at the outlet of the combustion chamber 36 to recover energy from a flow of combustion gases from this chamber and drive in rotation the high-pressure compressor 38 located upstream of the chamber and supplying the latter with pressurized air.

[0045] The turbine 3 comprises a rotor disc 2 centered on the longitudinal axis X and which is disposed at the outlet of the combustion chamber 36. The turbine blades 39 are mounted on the rotor disc 2 and driven in rotation by the flow of gas ejected by this combustion chamber 36.

[0046] The turbine 3 also includes a sealing flange 10 which is centered on the longitudinal axis X and arranged upstream of the rotor disc 2. This sealing flange 10 is movable in rotation and rotates with the rotor disc 2.

[0047] Furthermore, the sealing flange 10, together with the rotor disc 2, defines an annular ventilation cavity 9 designed to receive ventilation air and direct it to internal cooling circuits for the blades 39. For this purpose, channels 6a, 6b, forming ventilation air injectors, are regularly distributed around the longitudinal axis X, along the circumferential direction. Channels 6a, 6b are connected upstream to an annular bypass space 12 of the combustion chamber 36, also called the combustion chamber bottom, to convey the ventilation air from the high-pressure compressor 38 to the ventilation cavity 9. The annular space 12 extends around the combustion chamber 36.

[0048] As shown in Figures 2 to 5, the turbine 3 includes an annular cooling air injection housing 1 extending around the longitudinal axis X and comprising a radially external wall 4 and a downstream end wall 5. The housing 1 is fixed to the stator of the turbine 3. The sealing flange 10 is rotatably mounted relative to the stator. The housing 1 is positioned between the annular space 12 and the sealing flange 10.

[0049] The radially external wall 4 has the function of separating the annular bypass space 12 located radially below the combustion chamber 36 from cavities, such as the ventilation cavity 9, intended to cool the blades 39.

[0050] Each channel 6a, 6b extends axially, that is to say globally along the direction of the longitudinal axis X from an inlet opening 7 positioned at an upstream end 60 of the housing 1 and opening through the radially external wall 4, to an outlet opening 8 opening through the downstream end wall 5.

[0051] A first portion 46 of the canals 6a, 6b is delimited by two opposing circumferential end walls 53a, 53b, a radially external wall of canal 25 and a radially internal wall of canal 26, opposite the radially external wall of canal 25. The circumferential end walls 53a, 53b and the radially external and internal walls of canal 25, 26 extend axially from an internal face 52 of the radially external wall 4 to a downstream wall 54, opposite the downstream end wall 5.

[0052] Each channel 6a, 6b is traversed by a first ventilation airflow DI from the annular space 12 bypassing the combustion chamber 36 to supply air to the ventilation cavity 9.

[0053] More specifically, the ventilation air exiting the channels 6a, 6b enters the ventilation cavity 9 through orifices 41 formed in the sealing flange 10. The ventilation cavity 9 communicates with the internal cooling circuits arranged inside the blades 39.

[0054] Each channel 6a, 6b comprises a primary section 27 extending along the longitudinal axis X from the inlet opening 7 to a bend 29, and a secondary section 28 extending from the bend 29 to the outlet opening 8.

[0055] Channels 6a, 6b are inclined as described in application W02023047055.

[0056] The inlet opening 7 has a rectangular section and a central axis parallel to the longitudinal axis X. The outlet opening 8 also has a rectangular section.

[0057] The secondary section 28 exhibits a progressive variation in its orientation along a tangential direction Y between the section of the elbow 29 and the section of the outlet opening 8. By "progressive variation in orientation", we mean a variation in the orientation of a vector normal to the center of a section of the channel 6a, 6b and originating from the center of said section.

[0058] Preferably, the outlet section of the outlet opening 8 of each channel 6a, 6b extends circumferentially and tangentially in a plane perpendicular to the longitudinal axis X. The tangential direction is perpendicular to the longitudinal axis X and to the radial direction Z. Furthermore, the elbow 29 is advantageously oriented so that the airflow exiting the outlet opening 8 flows tangentially in the same direction as the direction of rotation of the rotor disc 2 facing it.

[0059] Each channel 6a, 6b includes a neck (not shown) forming a reduction in cross-section. The neck corresponds to the point in channel 6a, 6b with the smallest cross-section. The neck extends from the elbow 29 to the outlet opening 8.

[0060] The neck forms a calibrating section in the sense that it is this section that calibrates the flow rate through channels 6a and 6b. The neck also presents a The throat is oriented along a tangential component with respect to the longitudinal axis X. This allows the air passing through channels 6a and 6b to achieve a tangential velocity close to the rotor's rotational speed. The steeper the throat's incline, the higher the tangential velocity. The cross-sectional ratio between the outlet opening 8 and the throat is at least 2.

[0061] The housing 1 includes a downstream end ring 30 positioned at a downstream end 42 of the housing 1. The downstream end ring 30 is cantilevered.

[0062] The downstream end ring 30 is delimited axially by the downstream end wall 5 and the downstream wall 54, and radially by a radially external ring wall 33 and a radially internal ring wall 17, opposite the radially external ring wall 33.

[0063] A second portion 47 of channels 6a, 6b crosses the downstream end ring 30.

[0064] The outlet openings 8 of channels 6a, 6b open through the downstream end wall 5. The downstream end wall 5 and the downstream wall 54 extend radially, that is, along a radial plane including the radial direction Z which is orthogonal to the longitudinal axis X.

[0065] The housing 1 includes a flange 32 extending radially from the upstream end 60 and towards the longitudinal axis X.

[0066] The downstream end ring 30 is positioned opposite the flange 32.

[0067] The radially external wall of the annular crown 33 is positioned radially above the second portion 47 of canals 6a, 6b and extends axially for a length equivalent to approximately 1 / 3 of the length of canals 6a, 6b, for example. The radially external wall of the crown 33 extends axially from the distal end wall 5 to the distal wall 54.

[0068] The downstream end crown 30 is axially crossed by the second portion 47 of the channels 6a, 6b which includes at least a portion of the neck.

[0069] The circumferentially adjacent channels 6a, 6b are separated in pairs by an interchannel space 11. The interchannel space 11 extends in a general direction which is the radial direction Z, from a radially internal entrance 55 to a radially external exit 56. The interchannel space 11 also extends circumferentially with respect to channels 6a, 6b.

[0070] The inter-channel space 11 forms a passage to guide a portion of a second airflow D2 from the high-pressure compressor 38 of the turbine 3 to a purge cavity of the turbine 3. The inter-channel space 11 forms an air passage through which a diverted ventilation airflow D2' from the second airflow D2 flows. The diverted ventilation airflow D2' flows in a circumferential direction.

[0071] The inter-channel spaces 11 are arranged circumferentially around the longitudinal axis X so as to form a ventilation ring 14 extending circumferentially around the longitudinal axis X. The inter-channel spaces 11 are empty and each form an unobstructed channel, guiding the diverted ventilation airflow D2'.

[0072] Each inter-canal space 11 extends axially from the inner face 52 of the radially external wall 4 to the downstream wall 54 and circumferentially from a first circumferential end wall 53a of a first canal 6a to a second circumferential end wall 53b of a second canal 6b, opposite the first circumferential end wall 53a.

[0073] The circumferential width of the intercanal spaces 11 is as large as possible while maintaining sufficient thickness of the circumferential end walls 53a, 53b. The thickness of the circumferential end walls 53a, 53b separating each intercanal space 11 from a canal 6a, 6b is at least 0.5 mm.

[0074] The axial length of the inter-canal spaces 11 corresponds approximately to the distance between the radially external wall 4 and the downstream wall 54.

[0075] Preferably, there are as many inter-channel spaces 11 as there are channels 6a, 6b. The number of channels 6a, 6b must be sufficient to deliver an airflow necessary for the blades to cool them and not to generate significant pressure heterogeneities downstream of the downstream end ring 30.

[0076] The inter-channel spaces 11 cross radially through the ventilation ring 14 and the channels 6a, 6b cross axially through the ventilation ring 14 which extends from the internal face 52 of the radially external wall 4 to the downstream wall 54.

[0077] Each inter-channel space 11 extends from the radially internal inlet 55, which is in fluidic communication with the last stage of the high-pressure compressor 38 of the turbine 3, to the radially external outlet 56, which is in fluidic communication with the purge cavity of the turbine 3.

[0078] The ventilation ring 14 comprises an alternation of interchannel spaces 11 and first portions of channels 46.

[0079] The housing 1 includes a first abradable annular element 16 carried by a radially internal face 15 of the radially internal wall of the ring 17 and intended to cooperate with at least one first lip 19 of the sealing flange 10 to form a first sealing device. The first sealing device provides a seal between the downstream end ring 30 and the internal part 22 of the sealing flange 10.

[0080] The housing 1 includes a second abradable annular element 18 carried by a radially external face 23 of the radially external wall of the downstream end ring 33 and intended to cooperate with a second lip 20 connected to an external portion 24 of the sealing flange 10 to form a second sealing device. The second sealing device provides a seal between the downstream end ring 30 and the radially external portion 24 of the sealing flange 10.

[0081] The second portions 47 of the channels 6a, 6b are positioned between the first and second abradable elements 16, 18.

[0082] The first and second abradable elements 16, 18 run along the downstream end wall 5 of the downstream end ring 30.

[0083] The first and second sealing devices are labyrinth seals.

[0084] The first and second abradable elements 16, 18 are annular in shape and made of an abradable material, such as a honeycomb structure, which comes into contact with the wipers 19, 20. Each of the first and second abradable elements 16, 18 may have one or more tiers. The wipers 19, 20 may be straight or inclined and / or tiered.

[0085] In the example of figures 2 to 5, the first sealing device includes a first abradable element 16 having two first abradable surfaces 43 in stages, that is to say offset from one another along the radial direction Z, each cooperating with a first slit 19 inclined with respect to the first abradable surfaces 43.

[0086] The first 19 licks are supported by a first arm 45 connected to the internal part 22 of the sealing flange 10.

[0087] The second sealing device comprises a single second abradable surface 44 in contact with the second slit 20. The second slit 20 is straight, i.e. orthogonal to the second abradable surface 44.

[0088] The second lick 20 is supported by a second arm 48 connected to the external part 24 of the sealing flange 10.

[0089] The turbine 3 includes a third sealing device comprising three inclined third blades 21 supported by the second arm 48 and cooperating with a third abradable element 51 supported by the inner face 52 of the radially external wall 4. The third abradable element 51 is stepped and comprises three third abradable surfaces 50 offset from each other along the radial direction Z. Each third abradable surface 50 is in contact with one of the third blades 21 which is inclined with respect to the third abradable surface 50.

[0090] The third sealing device ensures a seal between the external part 24 of the sealing flange 10 and the radially external wall 4 of the housing 1.

[0091] In another embodiment, all the sealing devices can be brush seals.

[0092] The following describes the circulation of airflows in the ventilation circuits of turbine 3, regardless of the example presented previously.

[0093] As shown in Figure 2, each channel 6a, 6b is traversed by the first ventilation airflow DI from the annular bypass space 12 of the combustion chamber 36.

[0094] The second airflow D2 from the last stage of the high-pressure compressor 38 of the turbine 3 is divided into two airflows, one diverted airflow D2' passing through the inter-channel spaces 11 and a third airflow D3 passing through the first sealing device formed by the first abradable element 16 and the first two blades 19. The diverted airflow D2' represents between 95% and 80% of the second airflow D2, and preferably 90%.

[0095] The third airflow D3 then mixes with the first airflow DI to form an airflow that splits into a fourth airflow D4 and a fifth airflow D5. The fifth airflow D5 represents between 5% and 15% of the airflow generated by the mixing of the third airflow D3 and the first airflow D1.

[0096] The fourth airflow D4 passes through the orifices 41 formed in the sealing flange 10 to enter the ventilation cavity 9. The ventilation cavity 9 communicates with the internal cooling circuits arranged inside the blades 39. The fourth airflow D4 therefore supplies air to the internal cooling circuits of the blades 39.

[0097] The fifth airflow D5 then passes through the second sealing device formed by the second abradable element 18 and the second lick 20 to mix with the diverted airflow D2', generating a sixth airflow D6 supplying the turbine 3 purge cavity to cool it.

[0098] The fourth airflow D4 according to the invention has a higher tangential velocity and a lower temperature than an airflow generated solely by mixing the second airflow D2 and the first airflow D1 according to the prior art, resulting in a lower temperature of the air cooling the blades 39. The cooling efficiency of the turbine 3 ventilation circuit is therefore improved. Although the present invention has been described with reference to specific embodiments, it is evident that modifications and changes can be made to these examples without departing from the general scope of the invention as defined by the claims. In particular, individual features of the various embodiments illustrated / mentioned can be combined in additional embodiments. Therefore, the description and drawings should be considered in an illustrative rather than restrictive sense.

Claims

Demands

1. Cooling air injection housing (1) for a bladed rotor disc (2) of a high-pressure turbomachine turbine (3), the housing (1) extending about a longitudinal axis (X) and comprising a radially external wall (4), a downstream end wall (5), and several channels (6a, 6b) distributed circumferentially about the longitudinal axis (X), each channel (6a, 6b) being connected upstream to the radially external wall (4) and downstream to the downstream end wall (5), each channel (6a, 6b) forming an air injector extending axially from an inlet opening (7) through the radially external wall (4) to an outlet opening (8) through the downstream end wall (5), each channel (6a,6b) being configured to guide a first airflow (Dl) from an annular bypass space (12) of a combustion chamber (36) of the turbine (3) to a ventilation cavity (9) formed between the rotor disc (2) and a sealing flange (10) positioned upstream of the rotor disc (2), the channels (6a, 6b) being separated circumferentially in pairs by an inter-channel space (11), the channels (6a, 6b) delimiting a plurality of inter-channel spaces (11) arranged circumferentially around the longitudinal axis (X), the inter-channel spaces (11) each separating the radially outer wall (4) from the downstream end wall (5), the housing (1) being characterized in that: each inter-channel space (11) extends in a generally radial direction, from a radially inner inlet (55) to an outlet radially external (56),each inter-channel space (11) being configured to divert a portion of a second airflow (D2) from a high-pressure compressor (38) of the turbine (3) and passing through the radially internal inlet (55) and guide the portion of the second airflow (D2) from the radially external outlet (56) to a purge cavity of the turbine (3).

2. A housing (1) according to claim 1, wherein the channels (6a, 6b) are each delimited by two opposing circumferential channel end walls (53a, 53b), a radially external channel wall (25), and a wall radially internal canal wall (26), opposite the radially external canal wall (25), the circumferential end walls of the canal (53a, 53b) and the radially internal and external canal walls (25, 26) extending axially from the radially external wall (4) to a downstream wall (54), axially opposite the downstream end wall (5).

3. Carter (1) according to claim 2, wherein each inter-channel space (11) extends axially from the radially external wall (4) to the downstream wall (54) and circumferentially from a first circumferential end wall (53a) of a first channel (6a) to a second circumferential end wall (53b) of a second channel (6b), opposite the first circumferential end wall (53a).

4. A housing (1) according to any one of claims 2 or 3, comprising a downstream end ring (30) delimited axially on one side, downstream, by the downstream end wall (5) and, on the other side, upstream, by the downstream wall (54), and radially on one side, outwardly, by a radially external ring wall (33) and, on the other side, internally, by a radially internal ring wall (17), opposite the radially external ring wall (33), each inter-channel space (11) being positioned between the downstream end ring (30) and a flange (32) which extends radially towards the longitudinal axis (X) from an upstream end (60) of the radially external wall (4).

5. Housing (1) according to claim 4, comprising a first annular abradable element (16) carried by a radially internal face (15) of the radially internal wall of the crown (17) and intended to cooperate with at least a first lip (19) of the sealing flange (10) to form a first sealing device.

6. A housing (1) according to claim 5, comprising a second annular abradable element (18) carried by a radially external face (23) of the radially external wall of the crown (33) and intended to cooperate with a second lick (20) connected to a radially external part (24) of the sealing flange (10) to form a second sealing device.

7. Carter (1) according to claim 6, wherein the first and second abradable elements (16, 18) extend radially in projection from the downstream end wall (5).

8. Carter (1) according to any one of claims 1 to 7, wherein each channel (6a, 6b) comprises a primary section (27) extending along the longitudinal axis (X) from the inlet opening (7) to a curved portion (29), and a secondary section (28) extending from the curved portion (29) to the outlet opening (8), the outlet opening (8) being oriented so as to give a tangential orientation to an airflow passing through this outlet opening (8).

9. Turbine (3) for a turbomachine comprising a casing (1) as defined according to any one of claims 1 to 8.

Images