Turbine engine blade assembly

Abstract

The invention relates to a blade assembly (30, 30', 30") of a turbine engine (10), intended to be mounted about a longitudinal axis (X) and comprising: first and second blades (31, 31') circumferentially adjacent about the longitudinal axis (X) extending radially relative to the longitudinal axis (X) and each having an aerofoil profile delimited axially upstream by a leading edge (51, 51') and downstream by a trailing edge (52, 52'); a platform (32, 32', 32") comprising a flow stream surface (321, 321', 321") from which each blade (31, 31') extends, the platform (32, 32', 32") being intended to delimit a primary flow stream (21A) of a flow moving in a direction (SI) from the leading edge (51, 51') towards the trailing edge (52, 52') of each blade (31, 31'); the platform having a suction opening (35, 35', 35") and a delivery opening (36, 36', 36") arranged downstream of the suction opening (35, 35').

Description

[0001] DESCRIPTION

[0002] TITLE: TURBOMACHINE BLADE

[0003] Field of invention

[0004] The present invention relates to the field of turbomachines such as turboprops or turbojets.

[0005] More particularly, the invention relates to the field of turbines for aircraft turbomachines, and more specifically still to a blade for a distributor or for a moving wheel of such a turbine.

[0006] State of the prior art

[0007] A conventional aircraft turbomachine turbine comprises one or more stages each consisting of a distributor and a moving wheel. The distributor comprises fixed blades connected by their radially outer end to a casing and which are distributed circumferentially around a longitudinal central axis of the turbine so as to form a stator ring. The moving wheel comprises a disk and blades connected to the disk by their radially inner end while being circumferentially distributed around the disk. The distributor of a stage is configured so that a flow of fluid entering this stage, typically comprising gases from a combustion chamber, is accelerated and deflected by the stator blades towards the blades of the moving wheel of this stage so as to drive the latter in rotation around the longitudinal central axis.

[0008] In general, each nozzle and wheel blade of the turbine comprises a blade and two platforms which radially delimit between them a circumferential portion of an annular primary duct in which the blade extends. The fluid passing through the turbine flows mainly in this primary duct.

[0009] During the operation of a conventional turbine, the interaction of the fluid with the distributors and the moving wheels produces vortices at the level of the blade platforms, forming so-called "secondary" flows.

[0010] To illustrate this phenomenon, Figure 1 shows a portion of two blades IA and IB of a turbine nozzle 1, these blades IA and IB being circumferentially adjacent to each other. Figure 1 shows more particularly a radially internal portion of a blade 2 and a platform 3 of each of the blades IA and IB. The blade 2 of each blade IA and IB comprises a leading edge 4, a trailing edge 5, a lower surface 6 and an upper surface 7. The platform 3 of each blade IA and IB delimits radially inwards a circumferential portion of an annular primary duct in which a fluid flows in a direction SI going from the leading edge 4 to the trailing edge 5 of the blades 2.

[0011] Given the typical viscosity of the fluid flowing in the primary duct of a turbine, its flow along the surface of the platforms 3 has a velocity gradient GV1 such that, in the vicinity of this surface, the velocity of a layer of fluid is lower the closer this layer is to this surface. The fluid flowing in the primary duct is also subjected to a pressure gradient GP1 oriented in this example from the intrados 6 of the blade 2 of the blading 1B towards the extrados 7 of the blade 2 of the blading 1A. The pressure gradient GP1 is generally sufficient to deflect the layers of fluid flowing near the surface of the platforms 3.

[0012] This results in the appearance of different types of vortices. A first type of vortices T1, called "horseshoe", takes the form of two counter-rotating branches distributed on either side of the blades 2. A second type of vortices T2, called "passage vortices", develop between two adjacent blades 2. A third type of vortices T3, called "corner vortices", run along the connection lines between the blade 2 and the platform 3 of each blade.

[0013] Such secondary flows T1, T2 and T3, which typically occur at the root and tip of the blades 2, are not oriented in the direction SI of the main flow of the fluid passing through the primary duct and consequently lead to a reduction in the efficiency and an increase in the kerosene consumption of the turbomachine. Similar secondary flows also occur in the moving turbine wheels.

[0014] There is therefore a need to provide blading that can reduce secondary flows upstream of the blading so as to reduce unwanted effects.

[0015] Statement of the invention

[0016] The invention aims to remedy at least in part the drawbacks mentioned above relating to the techniques of the prior art.

[0017] To this end, the invention relates to a turbomachine blade intended to be mounted around a longitudinal axis X and comprising: a first and a second blade circumferentially adjacent around the longitudinal axis X extending radially with respect to the longitudinal axis X and each having an aerodynamic profile delimited axially upstream by a leading edge and downstream by a trailing edge, said leading edge and said trailing edge being separated by a chord distance, each blade comprising a pressure side wall and an extrados wall opposite said pressure side wall, said pressure side wall and said extrados wall each connecting said leading edge of the blade to said trailing edge of the blade; a platform comprising a vein surface from which each blade extends, said platform being intended to delimit a flow vein of a flow flowing in a direction SI going from said leading edge to said trailing edge of each blade;the platform having a suction opening and an ejection opening provided downstream of said suction opening.;

[0018] According to the invention, said suction opening opens, between the first and second circumferentially adjacent blades, onto said vein surface closer to the intrados wall side of the first blade than to the extrados wall side of the second blade and has an opening inlet arranged between said leading edge and said trailing edge of the first blade at a distance from said leading edge of the first blade less than or equal to half of said chord distance of the first blade. Furthermore, said suction opening has an oval shape oriented obliquely to the longitudinal axis while extending in a main direction a. Thus, the invention proposes an approach making it possible to at least partially resolve certain of the drawbacks of the prior art.

[0019] Indeed, the positioning of such a suction opening makes it possible to suck in a large part or even completely the so-called "horseshoe" vortex T1 illustrated in figure 1. By sucking it in as soon as it forms, its intensity will be reduced, which reduces losses. In addition, it will no longer interact with the extrados horseshoe vortex along the extrados profile in the downstream zone of the blading, which also has the consequence of reducing losses.

[0020] It should be noted that unlike a fairly wide suction mouth distributed evenly across the width of the platform close to the leading edge, such a suction opening allows one to concentrate solely on the suction of the intrados horseshoe vortex.

[0021] In other words, such a shape of the suction opening makes it possible to limit the formation of additional vortices by implementing a suction opening with a minimal number of corners. The invention thus makes it possible to reduce losses at the level of the blading by reducing secondary flows, in particular by sucking in the passage vortex. This also makes it possible to minimize pressure losses due to the geometry of the suction opening. This also makes it possible to reduce losses at the level of the downstream blading by reducing the angle and Mach distortion caused by the secondary flows close to the wall of the blading and by significantly reducing the intensity of the vortices at the outlet of the blading.

[0022] Furthermore, by implementing such a suction opening, a large portion of the secondary flows close to the leading edge are taken to reinject them downstream of the blading radially close to the trailing edge so as to have a passive system based on the upstream and downstream pressure difference. Indeed, the suction movement from the leading edge of the blading towards the trailing edge of the blading comes from the pressure gradient between the suction zone, upstream of the blading, and the ejection zone, downstream of the blading, because the pressure is significantly higher in the upstream zone of the blading than in the ejection zone. This thus results in a natural movement of the flow, which constitutes a significant advantage of the invention compared to so-called active solutions, requiring an external system.

[0023] According to a particular aspect of at least one embodiment of the invention, said suction opening is positioned in an area tangentially close to the intrados of the first blade. According to a particular aspect of at least one embodiment of the invention, said suction opening has an oblong shape, a circular shape, an ovoid shape, or a “drop” shape.

[0024] Such a shape of the suction opening thus makes it possible to limit the formation of additional vortices by implementing a suction opening with a minimal number of corners.

[0025] According to a particular aspect of at least one embodiment of the invention, the blade comprises an internal channel formed between said suction opening and said ejection opening.

[0026] According to a particular aspect of at least one embodiment of the invention, said internal channel has a sloping suction portion arranged in the vicinity of said suction opening, the inclination of said slope of said suction portion relative to said vein surface being progressive and decreasing towards the suction opening.

[0027] This prevents separation at the suction inlet which would cause pressure losses.

[0028] According to a particular aspect of at least one embodiment of the invention, said internal channel has an internal tubular wall.

[0029] In other words, said internal channel has a smooth internal tubular wall.

[0030] In other words, the said internal channel has an internal tubular wall which does not have any roughness or asperity.

[0031] Such a shape thus makes it possible to limit the formation of additional vortices because no irregularities come to disturb the flow.

[0032] According to a particular aspect of at least one embodiment of the invention, said platform is an internal platform, said vein surface of said internal platform being adapted to delimit radially inwards said primary flow vein.

[0033] According to a particular aspect of at least one embodiment of the invention, said platform comprises a second surface, radially opposite said vein surface, and from which extends radially inwards a foot connected at its radially internal end to a sealing element, said sealing element forming an abradable or lips of a dynamic seal and being intended to delimit an inter-lip cavity. According to a particular aspect of at least one embodiment of the invention, said internal channel extends into said foot, and said ejection opening opens at the level of said inter-lip cavity.

[0034] According to a particular aspect of at least one embodiment of the invention, said ejection opening opens onto said vein surface downstream of said trailing edge of each blade. According to a particular aspect of at least one embodiment of the invention, said platform comprises a second surface, radially opposite said vein surface, and from which a root extends radially inward so as to delimit a purge cavity downstream of said root, said ejection opening opening at said second surface into said purge cavity.

[0035] According to a particular aspect of at least one embodiment of the invention, said suction opening has an oval shape oriented in a main direction a extending angularly between a direction passing through said leading edge and said trailing edge of the first blade, and a direction which passes through said leading edge of the first blade and the leading edge of the second blade.

[0036] According to a particular aspect of at least one embodiment of the invention, a bisector of the angle formed between said direction passing through said leading edge and said trailing edge of the first blade, and said direction passing through said leading edge of the first blade and the leading edge of the second blade passes through said suction opening, said main direction a being preferably coincident with said bisector.

[0037] The invention also relates to a turbine for a turbomachine comprising: a distributor comprising at least one blading according to any one of the aforementioned embodiments, and / or a moving wheel comprising at least one blading according to any one of the aforementioned embodiments.

[0038] The invention also relates to a turbomachine comprising a turbine according to the aforementioned embodiment.

[0039] Presentation of figures

[0040] The invention, as well as the various advantages that it presents, will be more easily understood in the light of the following description of an illustrative and non-limiting embodiment thereof, and of the appended drawings among which:

[0041] [Fig. 1] is a partial schematic perspective view of a nozzle of a conventional turbine for an aircraft turbomachine, illustrating secondary flows which occur during operation of the turbomachine; [Fig. 2] is a schematic axial sectional view of a propulsion assembly for an aircraft;

[0042] [Fig. 3] is a partial schematic view in axial section of a low pressure turbine of a turbomachine;

[0043] [Fig. 4] is a schematic side sectional view of a blade according to a first embodiment of the invention;

[0044] [Fig. 5] is a schematic sectional view from above of the blading according to the first embodiment of the invention;

[0045] [Fig. 6] is a partial schematic perspective view of the blading according to the first embodiment of the invention;

[0046] [Fig. 7] is a partial schematic perspective view of the blading according to a second embodiment of the invention;

[0047] [Fig. 8] is a schematic side sectional view of a blade according to the second embodiment of the invention, and

[0048] [Fig. 9] is a schematic side sectional view of a blade according to a third embodiment of the invention.

[0049] Detailed description of an embodiment of the invention

[0050] The figures presented include a reference frame L, R and C defining respectively longitudinal (or axial), radial and circumferential directions orthogonal to each other.

[0051] Figure 2 shows an aircraft propulsion unit 10 comprising a turbomachine 11 shrouded by a nacelle 12. In this example, the turbomachine 11 is a twin-spool, twin-flow turbojet.

[0052] Subsequently, the terms “upstream” and “downstream” are defined with respect to a direction SI of flow of gases through the propulsion unit 10 when the latter is propelled.

[0053] The turbojet 11 has a longitudinal central axis X around which its various components extend, in this case, from upstream to downstream, a fan 13, a low-pressure compressor 14, a high-pressure compressor 15, a combustion chamber 16, a high-pressure turbine 17 and a low-pressure turbine 18. The compressors 14 and 15, the combustion chamber 16 and the turbines 17 and 18 form a gas generator.

[0054] During operation of the turbojet 11, an air flow enters the propulsion unit 10 through an air inlet upstream of the nacelle 12, passes through the fan 13 and then divides into a central primary flow and a secondary flow. The primary flow flows in a primary gas circulation duct 21A passing through the gas generator. The secondary flow flows in a secondary duct 21B surrounding the gas generator and delimited radially outwardly by the nacelle 12. In an exemplary embodiment, the low-pressure turbine 18 is as described below with reference to FIG. 3 which shows the turbine 18 along a radial plane which includes the longitudinal central axis X.

[0055] The longitudinal central axis X is also the axis of rotation of the rotor of this turbine 18.

[0056] In this example, the turbine 18 comprises four stages each comprising a distributor 25 and a moving wheel 26.

[0057] In a manner known per se, the moving wheels 26 are assembled axially to each other by annular flanges T1 and form the rotor of the turbine 18. The distributors 25 are connected to a casing 28 to form the stator of the turbine 18.

[0058] Each distributor 25 comprises a plurality of blades 30 circumferentially distributed around the axis X. With reference to the distributor 25 of the last stage of the turbine 18 of which a single blade 30 is shown in FIG. 3, the blades 30 each comprise a first blade and a second blade, an internal platform 32 and an external platform 33. The blades 30 are each connected to the casing 28 by a hooking element secured to their external platform 33.

[0059] Each moving wheel 26 comprises, for its part, a disc and a plurality of blades circumferentially distributed around the axis X. With reference to the moving wheel 26 of the last stage of the turbine 18, of which only one blade is shown in FIG. 3, the blades each comprise a first blade and a second blade, an internal platform and an external platform. The blades are each connected to the disc by a foot secured to their internal platform.

[0060] For each vane 30 of distributor 25, the platforms 32 and 33 each comprise a first surface from which each of the blades 31, 31' extends and which delimits a circumferential portion of the primary duct 21A in which the primary flow circulates. Thus, the first surface of the internal platform 32 of each vane 30 delimits the primary duct 21A radially inwards while the first surface of the external platform 33 of each vane 30 delimits the primary duct 21A radially outwards.

[0061] Similarly, for each moving wheel blade, the platforms each comprise a first surface from which the blade extends and which delimits a circumferential portion of the primary duct 21A. Thus, the first surface of the internal platform of each blade delimits the primary duct 21A radially inwardly while the first surface of the external platform of each blade delimits the primary duct 21A radially outwardly.

[0062] In the turbine 18 of Figure 3, the primary duct 21A is therefore generally annular.

[0063] A first embodiment of the invention is now presented in relation to Figures 4 to 6. It should be noted that this first embodiment applies to a nozzle vane or to a vane for a moving turbine wheel of a turbomachine.

[0064] As illustrated in these different figures, each blade 30 comprises: a first blade 31 and a second blade 31' circumferentially adjacent around the longitudinal axis X and extending radially with respect to the longitudinal axis X; a platform 32 comprising a vein surface 321 from which each of the first blade 31 and the second blade 31' extends, the platform being intended to delimit a primary flow vein 21A of a flow flowing in a direction SI going from the leading edge 51 to the trailing edge 52 of each of the blades. an internal channel 34

[0065] Here, the platform 32 is an internal platform, the vein surface 321 of the internal platform 32 radially inwardly delimiting the primary flow vein 21A. This internal platform 32 has a suction opening 35 and an ejection opening 36 arranged downstream of the suction opening 35.

[0066] In this embodiment, the blade comprises an internal channel 34 formed between said suction opening and said ejection opening.

[0067] This internal channel 34 has a smooth internal tubular wall so as not to generate additional vortex flows.

[0068] In other words, the inner tubular wall of this internal channel does not have any asperities or roughness that could disturb the fluid flow.

[0069] The first blade 31 has an aerodynamic profile delimited axially upstream by a leading edge 51 and downstream by a trailing edge 52, the leading edge 51 and the trailing edge 52 being separated by a chord distance Cx. The first blade 31 further comprises a pressure side wall 54 and an extrados wall 53 opposite the pressure side wall 54, such that the pressure side wall 54 and the extrados wall 53 each connect the leading edge 51 to the trailing edge 52.

[0070] For its part, the second blade 31' has an aerodynamic profile delimited axially upstream by a leading edge 51' and downstream by a trailing edge 52', the leading edge 51' and the trailing edge 52' being separated by a chord distance Cx'. The second blade 31' further comprises a pressure side wall 54' and an extrados wall 53' opposite the pressure side wall 54', such that the pressure side wall 54' and the extrados wall 53' each connect the leading edge 51' to the trailing edge 52'.

[0071] According to the invention, the suction opening 35 opens, between the circumferentially adjacent first blade 31 and second blade 31', onto the flow path surface 321 closer to the side of the intrados wall 54 of the first blade 31 than to the side of the extrados wall 53' of the second blade 31' and has an opening inlet 350 arranged between the leading edge 51 and the trailing edge 52 of the first blade 31 at a distance from the leading edge 51 of the first blade 31 less than or equal to half the chord distance Cx of the first blade 31.

[0072] In other words, the most downstream point of the suction opening 35 is arranged between the leading edge 51 and the trailing edge 52 of the first blade 31 at a distance from the leading edge 51 less than or equal to half the chord distance Cx.

[0073] Furthermore, according to the invention, the suction opening 35 has an oval shape oriented obliquely with respect to the longitudinal axis X while extending in a main direction a. Here, the suction opening 35 has an ovoid oval shape oriented in a main direction forming an angle substantially equal to 30 degrees with a direction passing through the leading edge 51 and the trailing edge 52 of the first blade 31, and also an angle substantially equal to 30 degrees with a direction configured to pass through the leading edge 51 and a leading edge of the second blade 31'.

[0074] More particularly, in this embodiment, said main direction a of the suction opening coincides with a bisector of the angle formed between the direction passing through the leading edge 51 and said trailing edge 52 of the first blade 31, and the direction passing through the leading edge 51 of the first blade 31 and the leading edge 51' of the second blade 31'.

[0075] In other embodiments not shown, the suction opening could have an oblong shape, a circular shape, or a "drop" shape.

[0076] Further, in other embodiments not shown, the main direction could have an angle of between 15 and 60 degrees with a direction passing through the leading edge and the trailing edge of the blade.

[0077] For example, the main direction could have an angle substantially equal to 30 degrees with a direction passing through the leading edge and the trailing edge of the blade.

[0078] As can be seen in particular in FIG. 6, the internal channel 34 has a sloping suction portion 340 arranged in the vicinity of the suction opening 35. This inclination of the slope of the suction portion 340 relative to the vein surface 321 is progressive and decreases towards the suction opening 35.

[0079] In other words, moving away from the suction opening, from this suction opening, the slope of the suction portion increases going downstream of the internal channel 34 until the end of this suction portion.

[0080] In this first embodiment, the platform 32 further comprises a second surface 322, radially opposite the vein surface 321, and from which extends radially inwards a foot 32A connected at its radially internal end to a sealing element 59 arranged opposite the first blade 31 and the second blade 31'. This sealing element 59 forms an abradable or lips of a dynamic seal and is intended to delimit an inter-lip cavity 590.

[0081] In this embodiment, the internal channel 34 extends into the foot 32A, so that the ejection opening 36 opens at the level of the inter-lip cavity 590.

[0082] A second embodiment of the invention is now presented in relation to Figures 7 and 8.

[0083] As with the first embodiment, this second embodiment applies to a nozzle vane or to a vane for a moving turbine wheel of a turbomachine.

[0084] The blade 30' of this second embodiment comprises: a first blade 31 and a second blade 31', similar to the blades implemented in the first embodiment, extending radially with respect to the longitudinal axis X and each having an aerodynamic profile delimited axially upstream by a leading edge and downstream by a trailing edge; a platform 32' comprising a vein surface 321' from which the blade 31 extends and having a suction opening 35' and an ejection opening 36' arranged downstream of the suction opening 35'.

[0085] In this embodiment, the blade also comprises an internal channel 34' formed between the suction opening 35' and the ejection opening 36' provided downstream of the suction opening 35'.

[0086] The suction opening 35' opens, between the circumferentially adjacent first blade 31 and second blade 31', onto the flow path surface 321' closer to the intrados wall 54 side of the first blade 31 than to the extrados wall 53' side of the second blade 31' and has an opening inlet 350' arranged between the leading edge 51 and the trailing edge 52 of the first blade 31 at a distance from the leading edge 51 of the first blade 31 less than or equal to half the chord distance Cx of the first blade 31.

[0087] As illustrated in particular in Figure 7, the suction opening 35' here has a drop shape oriented so that the opening inlet 350' is arranged on the narrowest part of the drop shape.

[0088] As seen in Figure 8, the platform 32' comprises a second surface 322', radially opposite the vein surface 321', and from which a foot 32A' extends radially inwards so as to delimit a purge cavity 50 downstream of the foot 32A'.

[0089] This purge cavity 50 is fluidically connected to the primary duct by an annular opening. This annular opening may for example extend axially and / or radially between a downstream end of the internal platform of the blades of a distributor and an upstream end of the internal platform of blades of a moving wheel belonging to the same stage as the distributor. In this embodiment, the root 32A' is connected at its radially internal end to a sealing element arranged opposite the first blade 31 and second blade 31'. This sealing element forms an abradable or lips of a dynamic seal and is intended to delimit an inter-lip cavity.

[0090] In this embodiment, the ejection opening 36' opens at the level of the second surface 322' into the purge cavity 50.

[0091] Thus, this allows the flow which is reinjected via the internal channel 34' at the ejection opening 36' to contribute to driving the rotor of the turbine.

[0092] It should be noted that, according to another embodiment, one could have a suction opening having a shape similar to the shape of the suction opening of the first embodiment, and an ejection opening positioned in a similar manner to the ejection opening of the second embodiment of the invention.

[0093] According to another embodiment, one could have a suction opening having a shape similar to the shape of the suction opening of the second embodiment, and an ejection opening positioned similarly to the ejection opening of the first embodiment of the invention.

[0094] According to yet another embodiment, one could have a suction opening having a shape similar to the shape of the suction opening of the first embodiment, or an ejection opening positioned similarly to the ejection opening of the second embodiment of the invention.

[0095] According to yet another embodiment, one could have a suction opening having a shape similar to the shape of the suction opening of the second embodiment, or an ejection opening positioned similarly to the ejection opening of the first embodiment of the invention.

[0096] A third embodiment of the invention is now presented in relation to Figure 9. As with the second embodiment, this third embodiment applies to a nozzle vane or to a vane for a moving turbine wheel of a turbomachine.

[0097] The 30" blading of this third embodiment comprises: a first blade 31 and a second blade 31', similar to the blades implemented in the first embodiment, extending radially with respect to the longitudinal axis X and each having an aerodynamic profile delimited axially upstream by a leading edge and downstream by a trailing edge; a platform 32" comprising a vein surface 321" from which each of the first blade 31 and second blade 31' extends, and having a suction opening 35" and an ejection opening 36" arranged downstream of the suction opening 35". In this embodiment, the blading comprises an internal channel 34" formed between the suction opening 35" and the ejection opening 36" arranged downstream of the suction opening 35".Here, unlike the first two embodiments of the invention, the ejection opening 36" opens onto the vein surface 321" of the platform 32" downstream of the trailing edge 52 of each of the first blade 31 and second blade 31'.

[0098] Furthermore, the ejection opening 36" opens at the level of the primary flow vein 21A defined by the first blade 31 and second blade 31'.

Claims

CLAIMS

1. A turbomachine (10) blade (30, 30', 30") intended to be mounted around a longitudinal axis (X) and comprising: a first and a second blade (31, 31') circumferentially adjacent around the longitudinal axis (X) extending radially with respect to the longitudinal axis (X) and each having an aerodynamic profile delimited axially upstream by a leading edge (51, 51') and downstream by a trailing edge (52, 52'), said leading edge (51, 51') and said trailing edge (52, 52') being separated by a chord distance (Cx, Cx'), each blade (31, 31') comprising a lower surface wall (54, 54') and an upper surface wall (53, 53') opposite said lower surface wall (54, 54'), said intrados wall (54, 54') and said extrados wall (53, 53') each connecting said leading edge (51, 51') of the blade (31, 31') to said trailing edge (52, 52') of the blade (51, 51'); a platform (32, 32', 32") comprising a vein surface (321, 321',321") from which each blade (31, 31') extends, said platform (32, 32', 32") being intended to delimit a flow vein (21A) of a flow flowing in a direction (SI) going from said leading edge (51, 51') towards said trailing edge (52, 52') of each blade (31, 31'); said platform (32, 32', 32") having a suction opening (35, 35', 35") and an ejection opening (36, 36', 36") arranged downstream of said suction opening (35, 35'), characterized in that said suction opening (35, 35', 35") opens, between the first and second circumferentially adjacent blades (31, 31'), onto said vein surface (321, 321', 321") closer to the intrados wall side (54) of the first blade (31) than to the extrados wall side (53') of the second blade (31') and has an opening inlet (350,350') arranged between said leading edge (51) and said trailing edge (52) of the first blade (31) at a distance from said leading edge (51) of the first blade (31) less than or equal to half of said chord distance (Cx) of the first blade (31), and in that said suction opening (35, 35', 35") has an oval shape oriented obliquely with respect to the longitudinal axis (X) while extending in a main direction (a).,

2. Blading according to the preceding claim, characterized in that said suction opening (35, 35', 35") has an oblong shape, a circular shape, an ovoid shape, or a "drop" shape.

3. Blading according to one of the preceding claims, characterized in that it comprises an internal channel (34, 34', 34") formed between said suction opening (35, 35', 35") and said ejection opening (36, 36', 36").

4. Blading according to the preceding claim, characterized in that said internal channel (34, 34', 34") has a sloping suction portion (340) arranged in the vicinity of said suction opening (35, 35', 35"), the inclination of said slope of said suction portion (340) relative to said vein surface (321) being progressive and decreasing towards the suction opening (35, 35', 35").

5. Blading according to one of claims 3 or 4, characterized in that said internal channel (34, 34', 34") has an internal tubular wall.

6. Blading according to one of the preceding claims, characterized in that said platform (32, 32', 32") is an internal platform, said vein surface (321, 321', 321") of said internal platform (32, 32', 32") being adapted to delimit radially inwards said primary flow vein (21A).

7. Blading according to one of the preceding claims, characterized in that said platform (32, 32', 32") comprises a second surface (322, 322'), radially opposite said vein surface (321, 321', 321"), and from which extends radially inwards a foot (32A) connected at its radially internal end to a sealing element (59), said sealing element (59) forming an abradable or lips of a dynamic seal and being intended to delimit an inter-lip cavity (590).

8. Blading according to the preceding claim dependent on one of claims 3 or 4, characterized in that said internal channel (34) extends into said foot (32A), and in that said ejection opening (36) opens at the level of said inter-licker cavity (590).

9. Blading according to one of claims 1 to 6, characterized in that said ejection opening (36") opens onto said vein surface (321) downstream of said trailing edge (52, 52') of each blade (31, 31').

10. Blading according to one of claims 1 to 6, characterized in that said platform (32') comprises a second surface (322'), radially opposite said vein surface (321'), and from which a foot (32A') extends radially inwards so as to delimiting a purge cavity (50) downstream of said foot (32A'), said ejection opening (36') opening at said second surface (322') into said purge cavity (50).

11. Blading according to one of the preceding claims, characterized in that said suction opening (35, 35', 35") has an oval shape oriented in a main direction (a) extending angularly between a direction passing through said leading edge (51) and said trailing edge (52) of the first blade (31), and a direction which passes through said leading edge (51) of the first blade (31) and the leading edge (51') of the second blade (31').

12. Blading according to claim 11, characterized in that a bisector of the angle formed between said direction passing through said leading edge (51) and said trailing edge (52) of the first blade (31), and said direction passing through said leading edge (51) of the first blade (31) and the leading edge (51') of the second blade (31') passes through said suction opening (35), said main direction (a) preferably being merged with said bisector.

13. Turbine for a turbomachine comprising: a distributor comprising at least one blading (30, 30', 30") according to any one of claims 1 to 12, and / or a moving wheel comprising at least one blading (30, 30', 30") according to any one of claims 1 to 12.

14. A turbomachine comprising a turbine according to claim 13.

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