A turbine blade including ribs between cooling outlets having cooling holes

Abstract

The main object of the present invention is a turbine blade (18) of a turbine engine, the turbine blade comprising a platform, a blade, a cooling cavity supplying a plurality of cooling outlets (25) arranged along the trailing edge (BF), and two radially adjacent cooling outlets (25), a rib (40) being defined between the two radially adjacent cooling outlets, characterized in that at least one cooling hole (41) is formed in the thickness of at least one rib (40), and / or in the thickness of a part (Po) of the trailing edge fillet (26) located in the axial extension of at least one rib (40), to ensure fluid communication of the cooling flow between the inside and the outside of the blade (18) to cool at least one rib (40).

Description

Technical Field

[0001] The present invention relates to the general field of cooling turbine blades of a turbine, and more particularly to the field of cooling moving turbine blades for a turbine.

[0002] The present invention is applicable to any type of aircraft turbine or land turbine. The present invention is particularly applicable to moving turbine blades of an aircraft turbine, such as a turbojet and a turboprop engine, such as a turbofan engine. The present invention can also be applied to moving blades of an industrial gas turbine. The present invention also relates to the cooling of moving blades of a high-pressure turbine or a low-pressure turbine. Background Art

[0003] In order to design engines that are increasingly efficient with low consumption, the following turbine blades have been developed: the turbine blades have increasingly smaller dimensions and resist increasingly high thermal and mechanical stresses, such as temperature, pressure, rotational speed, etc.

[0004] It is well known that the blades of a gas turbine of a turbine, particularly the blades of a high-pressure turbine, are subjected to high temperatures of combustion gases during the operation of the engine. The values reached by these temperatures are much higher than the values of the temperatures that the respective components in contact with these gases can withstand without being damaged, which limits the service life of the respective components.

[0005] It is also well known that an increase in the temperature of the gases of a high-pressure turbine enables an increase in the efficiency of the turbine, and thus an increase in the ratio between the thrust of the engine and the weight of the aircraft propelled by the turbine. Therefore, efforts have been made to produce turbine blades that can withstand increasingly high temperatures. In addition, the improvement of turbine blades enables a reduction in the fuel consumption of the engine.

[0006] One of the existing solutions for improving the blades, particularly the mechanical strength of the blades, is to reduce the operating temperature of the blades by more effective cooling. This cooling is particularly obtained by a cooling circuit provided in the blade, which is intended to reduce the temperature of the blade. Due to this circuit, the cooling air typically introduced into the blade through the root of the blade passes through the root of the blade along a path formed by a cavity formed in the blade before being ejected through holes (or drilled holes) opened at the surface of the blade, particularly at the trailing edge of the blade. The improvement of the cooling circuit of the blade enables a reduction in the air flow rate required for cooling the blade, and also enables an increase in the service life of the blade and / or ensures the achievement of the service life target in the case of an increase in the temperature at the inlet of the turbine stage.

[0007] In addition, in order to improve the efficiency of the blade, it is also possible to improve the blade by improving the aerodynamic profile.

[0008] Solutions aimed at improving the cooling and the aerodynamic profile at the trailing edge of the moving blades of a high-pressure turbine have already been described in the prior art. By way of example, French patent application FR 3 041 989 A1 discloses the cooling of the trailing edge of a high-pressure turbine blade by three different cooling zones. French patent application FR 2 864 990 A1 describes a solution for improving the cooling air discharge slots at the trailing edge of a high-pressure turbine blade.

[0009] However, there is still a need to further improve the cooling efficiency at the trailing edge of the turbine blade, in particular to ensure the mechanical strength of the turbine blade and to maximize the aerodynamic efficiency. In particular, in the case of cooling the trailing edge by cooling slots, the ribs between the slots are hardly affected by the cooling film located upstream, and an excessive temperature gradient exists along the ribs. Summary of the Invention

[0010] Thus, an object of the present invention is to at least partially overcome the above-mentioned needs and the drawbacks associated with the embodiments of the prior art.

[0011] Thus, according to one aspect of the present invention, an object of the present invention is a blade of a turbine of a turbine, which is intended to be mounted around a rotation axis and includes a platform and a blade. The platform is particularly an inner platform. The blade extends in a radial direction with respect to the rotation axis. The blade extends radially from the platform from the inside to the outside and ends at a tip. The blade includes a leading edge and a trailing edge located downstream of the leading edge, and the blade includes a lower surface wall and an upper surface wall. The lower surface wall and the upper surface wall each connect the leading edge to the trailing edge. The lower surface wall and the upper surface wall are connected to each other by a trailing edge fillet at the trailing edge.

[0012] The blade includes a cooling cavity that supplies a cooling flow to a plurality of cooling outlets. The cooling outlets are particularly cooling slots. The cooling outlets particularly extend substantially axially for the most part and appear on the trailing edge. The cooling outlets are arranged on one of the lower surface wall and the upper surface wall along the trailing edge, between the platform and the tip. Two adjacent cooling outlets are defined by a rib. The rib particularly extends mainly axially between an upstream end and a downstream end. The upstream end is radially located between two adjacent cooling outlets and is particularly substantially radially aligned with the upstream ends of the adjacent cooling outlets. The downstream end appears on the trailing edge and is particularly substantially radially aligned with the downstream ends of the adjacent cooling outlets.

[0013] It is characterized in that at least one cooling hole is formed in the thickness of at least one rib, between the upstream end and the downstream end, and / or is formed in the thickness of a part of the axial extension of the trailing edge fillet that is particularly substantially axially aligned with at least one rib, downstream of the downstream end, to ensure fluid communication of the cooling flow between the inside and the outside of the blade to cool the at least one rib.

[0014] Due to the present invention, it is possible to reduce the fuel consumption of a turbine engine by reducing the flow rate required to cool the blades, in particular the moving blades of a high-pressure turbine, and the service life of such blades is the same as that of turbine blades incorporating conventional cooling circuits. Additionally, compared to blades incorporating conventional solutions for cooling the trailing edge (such as slots at the trailing edge), it is possible to increase the service life of the blades, in particular the high-pressure turbine blades.

[0015] The turbine blade according to the present invention may further include one or more of the following features, with the one or more features being employed individually or in any possible technical combination.

[0016] The at least one cooling hole may include a cooling hole, in particular a drilled hole, which preferably has a shape with a circular and / or elliptical cross-section and is formed in a thickness of a part of an axially extending portion of a trailing edge fillet that is particularly substantially axially aligned with at least one rib, downstream of the downstream end, and the axis of the cooling hole is particularly arranged in an extension of the median axis of the at least one rib, and in particular remains substantially aligned with the median axis of the at least one rib, the median axis extending along the rib.

[0017] In particular, the cooling hole may have a cylindrical portion having a radial cross-sectional dimension, in particular a diameter, which preferably remains substantially constant from the inside of the blade to the outside of the blade through the wall of the part of the trailing edge fillet, and in particular is between 0.10 mm and 0.50 mm.

[0018] The cooling hole may include a groove that appears on the trailing edge and expands outwardly in an extension of the cylindrical portion of the cooling hole.

[0019] In particular, the cooling hole may have a cylindrical portion having a radial cross-sectional dimension, in particular a diameter, which preferably remains substantially constant, and in particular is between 0.10 mm and 0.50 mm, from the inside of the blade to the entrance of the groove through the wall of the part of the trailing edge fillet, the groove being formed within the wall of the part of the trailing edge fillet and appearing on the outside of the blade at the exit of the groove. The groove may have a non-zero axial dimension and a radial dimension, in particular a variable radial dimension that is greater than the radial dimension of the cooling hole upstream of the groove.

[0020] Furthermore, the ratio between the radial dimension of the cooling hole upstream of the groove and the diameter of the trailing edge fillet may be strictly within the range of 0.25 to 0.85.

[0021] In addition, the at least one cooling hole may comprise a cooling hole, in particular a drilled hole, formed through the thickness of at least one rib, between an upstream end and a downstream end, the drilled hole having in particular a cylindrical shape and / or a first part having a cylindrical shape and a second part having a flared shape including a diverging wall.

[0022] The cooling hole may have a cylindrical shape, the ratio of the cross-sectional diameter of the cooling hole to the radial dimension of the rib being strictly between 0.20 and 0.85. Additionally, the ratio of the axial distance of the cooling hole relative to the downstream end of the rib to the axial distance of the rib between the upstream end and the downstream end of the rib may be strictly between 0.1 and 0.9.

[0023] In addition, at least one cooling hole may be formed through the thickness of each rib, between an upstream end and a downstream end, and at least one other cooling hole may be formed through the thickness of a part of an axially extending portion of the trailing edge fillet that is particularly substantially axially aligned with each rib, downstream of the downstream end, to ensure fluid communication of the cooling flow between the interior and the exterior of the blade to cool each rib.

[0024] In addition, the at least one cooling hole may comprise a plurality of cooling holes, each cooling hole being formed through the thickness of a rib, between an upstream end and a downstream end, and / or being formed through the thickness of a part of an axially extending portion of the trailing edge fillet that is particularly substantially axially aligned with the rib, the radial pitch of the cooling holes may be between 2 times and 4 times the radial dimension of the cooling hole, in particular the diameter of the cooling hole, the radial pitch corresponding to the radial dimension between two adjacent holes and being measured from the center of the outlet section of the hole to the center of the outlet section of the adjacent hole.

[0025] In addition, the radial pitch of the ribs may be between 2 times and 8 times the radial dimension of the ribs, in particular the width of the ribs, the radial pitch corresponding to the radial dimension between two radially adjacent ribs and being measured from the center of the rib to the center of the adjacent rib.

[0026] The at least one cooling hole may further comprise a plurality of cooling holes, each cooling hole being formed through the thickness of a rib, between an upstream end and a downstream end, and / or being formed through the thickness of a part of an axially extending portion of the trailing edge fillet that is particularly substantially axially aligned with the rib, the radial height of the region including the cooling holes may be between 10% and 40% of the radial height of the blade, the radial height of the blade corresponding to the radial dimension of the blade between the platform and the tip. The region including the cooling holes may be continuous or discontinuous. In the case where the region including the cooling holes is discontinuous, the radial height of the region may correspond to the sum of the radial heights of at least two local parts including the cooling holes.

[0027] Preferably, the blade may be a moving blade for a moving turbine wheel section of a turbine, particularly a high-pressure turbine.

[0028] Furthermore, according to another aspect of the present invention, another object of the present invention is a turbine for a turbine, characterized in that the turbine comprises at least one moving wheel section, and at least one moving wheel section comprises a plurality of moving blades as described above, and the turbine is preferably a high-pressure turbine.

[0029] In addition, according to another aspect of the present invention, the object of the present invention is also a turbine for a turbine, characterized in that the turbine comprises at least one distributor, and at least one distributor comprises a plurality of fixed blades as described above, and the turbine is preferably a high-pressure turbine.

[0030] Furthermore, according to another aspect of the present invention, another object of the present invention is a turbine, characterized in that the turbine comprises at least one turbine as described above, and the turbine is preferably a twin-spool turbine.

[0031] The blade, turbine and turbine according to the present invention may include any one of the features described in the specification, and the features may be adopted alone or in combination with other features according to any technical feasibility. Description of the Drawings

[0032] The present invention can be better understood by reading the following detailed description of non-limiting examples of embodiments of the present invention, and by examining the schematic diagrams and partial views of the drawings, in which:

[0033] Figure 1 is a schematic axial cross-sectional view of an example of a turbofan engine suitable for implementing the present invention, Figure 2 shows in perspective view as Figure 1 an example of a moving turbine blade of a turbojet engine as shown, Figure 3A and Figure 3B shows two embodiments of a turbine blade according to the present invention in a partially enlarged side view,

[0034] Figure 4 shows schematically in a cross-sectional view taken along Figure 3B B-B of Figure 3B the geometric configuration of the cooling holes of the turbine of

[0035] Figure 5A and Figure 5B and Figure 6A and Figure 6B shows other embodiments of a turbine blade according to the present invention in a partially enlarged side view.

[0036] In all of these figures, the same reference numerals may denote the same or similar elements.

[0037] In addition, the various parts shown in the figures are not necessarily shown to the same scale in order to make the figures more legible. Detailed Description

[0038] Throughout the specification, it is noted that the axis 2 of the turbine 1 is referred to as the radially symmetric axis of the turbine (see Figure 1 ). The axial direction of the turbine 1 corresponds to the rotational axis 2 of the turbine 1. The radial direction of the turbine 1 is the direction perpendicular to the axis 2 of the turbine 1. In addition, unless otherwise specified, the adjectives and adverbs axial, radial, axially and radially are used with reference to the above-mentioned axial and radial directions, and the terms inner (or internal) and outer (or external) are used with reference to the radial direction, such that the inner part of an element is closer to the axis 2 of the turbine 1 than the outer part of the same element. Additionally, it is noted that the terms upstream and downstream are considered with respect to the main direction 5 of the normal airflow of the turbine 1 (from upstream to downstream).

[0039] Figure 1 An aircraft turbine 1 is shown, the aircraft turbine being, for example, a turbofan engine and a twin-spool turbojet engine herein, the aircraft turbine having a central longitudinal axis 2 about which the various components of the aircraft turbine extend. The aircraft turbine includes, from upstream to downstream along the main direction 5 of the airflow through the turbine, a fan 3, a low-pressure compressor 4, a high-pressure compressor 6, a combustion chamber 11, a high-pressure turbine 7 and a low-pressure turbine 8.

[0040] Generally, after the air passes through the fan, the air is divided into a central main stream 12a and a secondary stream 12b surrounding the main stream. The main stream 12a flows in a main airflow path 14a that passes through the compressors 4, 6, the combustion chamber 11 and the turbines 7, 8. Further, the secondary stream 12b flows in a secondary stream path 14b that is radially delimited towards the outside by the engine casing and surrounded by the nacelle 9.

[0041] Generally, the high-pressure turbine 7 has alternately moving wheels and distributors. The distributor includes a plurality of fixed vanes, and the moving wheel includes a plurality of moving blades 18, as Figure 2 shown.

[0042] The moving blades 18 of the high-pressure turbine 7 can be mainly cooled at the trailing edge by drilling holes formed in the thickness of the trailing edge fillet or by cooling grooves.

[0043] These two cooling techniques have advantages and disadvantages. Thus, from a thermo-mechanical point of view, drilling in the thickness of the trailing edge fillet has a good compromise. The drilling ensures a controlled thermal level at the trailing edge. However, considering the minimum thickness of the material in this area, this requires defining a trailing edge of a relatively thick aerodynamic profile, which has an adverse effect on the aerodynamic efficiency of the aerodynamic profile. In addition, the slot at the trailing edge makes it possible to define a relatively fine aerodynamic dihedral. However, from a thermal point of view, the efficiency of the slot is lower than that of the drilling that emerges into the thickness of the trailing edge fillet. In fact, the air that is discharged at the inlet of the trailing edge slot to cool the bottom of the slot by film heats up when it comes into contact with the air in the mainstream path as it passes through the bottom of the slot.

[0044] As an example, Figure 2 a moving blade 18 of a turbine is shown in perspective, for example, such as the moving blade of the high-pressure turbine 7 as previously referred to Figure 1 above. The blade 18 is fixed to a turbine rotor (not shown) by a fitting 15 that is generally fir-tree shaped.

[0045] The blade 18 is in the shape of an aerodynamic surface formed by vanes 30 that extend radially between a blade root 16 and a blade tip S in a radial direction 23 and extend axially between a leading edge BA and a trailing edge BF. Thus, the aerodynamic surface of the blade 18 defines a lower surface wall 20 and an upper surface wall 21.

[0046] The fitting 15 of the blade 18 is connected to the blade root 16 at an inner platform 28 that defines a wall for the flow path of combustion gases through the turbine.

[0047] The blade 18 needs to be cooled as it is subjected to the high temperature of the combustion gases passing through the turbine. To this end, in a manner known per se, the blade 18 includes one or more internal cooling circuits. Each cooling circuit includes at least one cavity 24 that extends radially between the blade root 16 and the blade tip S. This cavity is supplied with cooling air through an inlet opening (not shown) at one of the radial ends of the radial end of the cavity. This inlet opening is generally provided at the fitting 15 of the blade 18. In order to discharge the cooling air flowing in the cavity 24 of the cooling circuit, a plurality of slots 25 are distributed along the trailing edge BF between the blade root 16 and the blade tip S. These discharge slots 25 lead into the cavity 24 and emerge at the lower surface wall 20 of the blade 18, at the trailing edge BF of the blade.

[0048] In order to improve the cooling at the trailing edge and to obtain an improved aerodynamic profile of the moving blade 18, the present invention proposes to define a retractable configuration for injecting cooling air at the trailing edge, associated with the dihedral at the trailing edge of the aerodynamic profile, which can also be retracted according to the radial height and according to the local thermo-mechanical requirements, and to maximize the aerodynamic efficiency.

[0049] In particular, in the case of cooling the trailing edge BF by means of the cooling slots 25, the ribs 40 between the slots are hardly affected by the upstream cooling film, and a significant temperature gradient exists along the ribs.

[0050] Thus, Figure 3A As shown in Figure 2 The partial enlarged perspective view of the blade 18 shows a first exemplary embodiment according to the present invention. It should be noted that for these Figures 3B to 6B , it is not necessary to describe again the features of the examples described in conjunction with Figure 3A and which are also applicable to Figures 3B to 6B the embodiments.

[0051] The geometry of the cooling slots 25 is shown more precisely in Figure 3A . Each cooling slot 25 includes a recessed (or concave) wall 32, a radially inner flange (or step) 34, a radially outer flange (or step) 36, and a side wall 38 provided with an opening (not shown) leading to the cavity 24 of the cooling circuit.

[0052] The radially inner flange refers to the flange arranged on the side of the blade root 16. Similarly, the radially outer flange refers to the flange arranged on the side of the blade tip S. The concepts of "radially inner" and "radially outer" are understood with respect to the radial direction in which the blade extends. The recessed wall 32 extends radially between the radially inner flange 34 and the radially outer flange 36, and axially between the side wall 38 and the trailing edge BF of the blade. In addition, the radially inner flange 34 and the radially outer flange 36 extend between the recessed wall 32 and the aerodynamic surface of the vane 30.

[0053] Thus, this specific geometry of the cooling slots 25 ensures the guiding of the air from the cavity 24 of the cooling circuit and enables the cooling of the trailing edge BF of the blade, which is the thinnest part of the blade and is therefore most easily exposed to the high temperature of the combustion gases.

[0054] The cooling channels 25 extend substantially axially on the lower surface wall 20 and emerge at the trailing edge BF. The ribs 40 are located between two radially adjacent channels 25 and extend substantially axially between an upstream end 40a and a downstream end 40b, the upstream end being substantially radially aligned with the upstream end of the radially adjacent cooling channel 25 and the downstream end being substantially radially aligned with the downstream end of the radially adjacent cooling channel 25. Thus, the blade 18 includes a plurality of ribs 40 between the cooling channels 25.

[0055] According to the invention, at least one cooling hole 41, 42, 43, 44 is formed in the thickness of at least one rib 40, between the upstream end 40a and the downstream end 40b, and / or is formed in the thickness of a portion Po of the trailing edge fillet 26 that is substantially axially aligned with at least one rib 40, downstream of the downstream end 40b, to ensure fluid communication of the cooling flow between the interior and the exterior of the blade 18 to cool the at least one rib 40.

[0056] Specifically, in Figure 3A the embodiment, the cooling holes 41 are formed in the thickness of the portion Po of the trailing edge fillet 26, each portion being substantially axially aligned with a rib 40.

[0057] These cooling holes 41 take the shape of drilled holes, here of circular cross-section, but may also be of elliptical cross-section, and are formed in the thickness of the trailing edge fillet 26, between two radially adjacent channels 25, to ensure subsequent cooling of the areas subjected to high thermal loads. The configuration of the holes 41 may depend on the thermal conditions of the blade 30 and may be associated with a local thickening of the trailing edge BF of the aerodynamic profile for drilling.

[0058] Compared with a blade cooled only by the channels 25, the solution according to the invention with holes 41 enables more effective cooling by pumping the ribs 40 at the trailing edge BF. Depending on the radial dimension, in particular the diameter, reserved for the drilled holes 41, a local increase in the value of the radius of the trailing edge fillet 26 can be achieved, for example an increase in the value of the radius of the trailing edge fillet from 20% to 100% compared to the profile of a blade cooled only by the cooling channels at the trailing edge.

[0059] As Figure 3A shown, the holes 41 have a drilling axis that is substantially aligned with the median axis AA of the rib 40. However, this drilling axis can be offset as required, in particular in response to manufacturing requirements.

[0060] Additionally, the holes 41 may be located over all or part of the radial height H of the blade 18, or only at the ribs 40 where additional cooling is required. In particular, according to local thermomechanical requirements, the radial height HP of the area including the cooling holes 41 is between 10% and 40% of the radial height H of the blade 30, which corresponds to the radial dimension of the blade 30 between the inner platform 28 and the tip S, as Figure 2 shown. It should be noted that the presence of such holes 41 at a larger percentage of the radial height H (e.g., between 30% and 40%) is beneficial for thermomechanical resistance and thus for the service life of the blade 18, but is not beneficial for the aerodynamic performance of the blade.

[0061] In Figure 3A the example of

[0062] In Figure 3B the example of

[0063] the cooling holes 41 have a constant diameter d that passes through the wall of the trailing edge fillet 26 from the inside to the outside of the blade 18, and this constant diameter is particularly between 0.10 mm and 0.50 mm. Figure 3B the B-B of Figure 3B shown in perspective in Figure 4 and in cross-section in Figure 4 . Each groove 42g is formed within the wall of each part Po of the trailing edge fillet 26 and exits on the outside of the blade 18 at the outlet of the groove. Each groove 42g has a non-zero axial dimension, a radial dimension d' at the bottom of the groove, and a radial dimension D at the outlet of the groove, and this radial dimension d' is greater than the diameter d of each hole 42 upstream of the groove 42g, and this radial dimension D is greater than the radial dimension d' at the bottom of the groove. More specifically, according to BF verified the following relationship: d < d' < D. Additionally, the radial dimension D (referred to as the diameter of the groove 42g) at the outlet of the groove is strictly between the diameter d upstream of the groove 42g and the diameter D BF of the trailing edge fillet, i.e., d < D < D Figure 3B shown.

[0064] Preferably, the ratio between the diameter d of each cooling hole 42 upstream of the groove 42g and the diameter D BF of the trailing edge fillet 26 is strictly in the range of 0.25 to 0.85. In other words, 0.25·D BF < d < 0.85·D BF .

[0065] In addition, as Figure 3B shown, the radial pitch p of the cooling holes 41, 42 is between 2 times and 4 times the diameter d of the holes 41, 42. This radial pitch corresponds to the radial dimension between two radially adjacent holes and is measured from the center of the exit cross-section of the hole to the center of the exit cross-section of the radially adjacent hole. In addition, the radial pitch of the rib 40 can be between 2 times and 8 times the width e of the rib 40. This radial pitch corresponds to the radial dimension between two radially adjacent ribs 40 and is measured from the center of the rib to the center of the adjacent rib.

[0066] Figure 5A Another embodiment according to the present invention is shown, in which cooling holes 43 are formed in the thickness of the rib 40, between the upstream end 40a and the downstream end 40b.

[0067] These holes 43 can be formed by drilling and, as Figure 5A shown, have a cylindrical shape, or even a shape including a first part with a cylindrical shape and a second part with a flared shape (the second part includes a diverging wall) ("post-sector hole" type cooling hole), having a cooling hole 44 in the example as Figure 5B shown.

[0068] In Figure 5A and 5B cases, the preferred cooling mode for cooling the rib 40 is film cooling, while in Figure 3A and 3B cases, the preferred cooling mode for cooling the rib 40 is pumped cooling.

[0069] In Figure 5A example, each cooling hole 43 has a cylindrical shape, and the ratio of the cross-sectional diameter d of the cooling hole to the radial dimension e of the rib 40 (i.e., the width of the rib 40) is strictly between 0.20 and 0.85. In other words, the following relationship holds: 0.20·e < d < 0.85·e.

[0070] In addition, the positioning of the hole 43 relative to the downstream end 40b of each rib 40 depends on the aerothermal and manufacturing capabilities. In particular, the axial distance l of each cooling hole 43 relative to the downstream end 40b of the rib 40 (i.e., the distance of the drilled hole relative to the end of the rib) and the axial distance L of the rib 40 between the upstream end 40a and the downstream end 40b of the rib (i.e., the length of the rib) have a ratio that is strictly between 0.1 and 0.9. In other words, the following relationship holds: 0.1·L < l < 0.9·L.

[0071] In addition, the foregoing can be combined with reference to Figure 3A , Figure 3B , Figure 5Aand Figure 5B the example described

[0072] For example Figure 6A the example of combines Figure 3A and Figure 5A the embodiments of, Figure 6B the example of combines Figure 3B and Figure 5B the embodiments of. Thus, in Figure 6A and Figure 6B embodiments are obtained that combine pumped cooling and film cooling. Of course, all other combinations are possible depending on any design constraints. In particular, in the examples of Figure 5A and Figure 5B the positions of the holes 43, 44 can vary between the upstream end 40a and the downstream end 40b. For example, the positions of the holes 43, 44 can be centered between these ends 40a and 40b, or located near the downstream end 40b, i.e., near the outlet of the slot 25.

[0073] Of course, the present invention is not limited to the embodiments just described. Those skilled in the art can make various modifications to the present invention.

Claims

1. A blade (18) of a turbine (7) of a turbine, the blade being intended to be mounted about a rotation axis (2) and comprising a platform (28) and a blade profile (30), the blade profile extending in a radial direction (23) with respect to the rotation axis (2), the blade profile extending radially from the platform (28) from the inside to the outside and ending at a tip (S), the blade profile (30) comprising a leading edge (BA) and a trailing edge (BF), the trailing edge (BF) being located downstream of the leading edge (BA), and the blade profile (30) comprising a lower surface wall (20) and an upper surface wall (21), each of the lower surface wall and the upper surface wall connecting the leading edge (BA) to the trailing edge (BF), the lower surface wall (20) and the upper surface wall (21) being connected to each other at the trailing edge (BF) by a trailing edge fillet (26). The blade (18) comprises a cooling cavity (24) for supplying a cooling flow to a plurality of cooling outlets (25), the cooling outlets being present on the trailing edge (BF), the cooling outlets (25) being arranged along the trailing edge (BF) on one of the lower surface wall (20) and the upper surface wall (21), between the platform (28) and the tip (S), two radially adjacent cooling outlets (25) being delimited by a rib (40), the rib extending between an upstream end (40a) and a downstream end (40b), the upstream end being radially located between the two radially adjacent cooling outlets (25), the downstream end being present on the trailing edge (BF). Characterized in that At least one first cooling hole (43, 44) is formed in the thickness of at least one rib (40) between the upstream end (40a) and the downstream end (40b), and / or at least one second cooling hole (41, 42) having a cylindrical portion is formed in the thickness of a part (Po) of the trailing edge fillet (26) in an axially extending portion of at least one rib (40) downstream of the downstream end (40b) to ensure fluid communication of the cooling flow between the interior and exterior of the blade (18) to cool the at least one rib (40).

2. The blade (18) according to claim 1, characterized in that The at least one second cooling hole (41, 42) formed in the thickness of a part (Po) of the trailing edge fillet (26) comprises a drilled hole.

3. The blade (18) according to claim 1 or 2, characterized in that The cylindrical portion of the at least one second cooling hole (41, 42) formed in the thickness of a part (Po) of the trailing edge fillet (26) has a radial cross-sectional dimension between 0.10 mm and 0.50 mm.

4. The blade (18) according to claim 3, characterized in that The at least one second cooling hole comprises a groove (42g) that appears on the trailing edge fillet (26) and expands outwardly in an extension of the cylindrical portion of the at least one second cooling hole.

5. The blade (18) according to claim 4, characterized in that The radial cross-sectional dimension of the at least one second cooling hole upstream of the groove (42g) and the diameter (D BF ) have a ratio that is strictly within the range of 0.25 to 0.

85.

6. The blade (18) according to claim 1 or 2, characterized in that The at least one first cooling hole (43, 44) formed in the thickness of at least one rib (40) comprises a drilled hole having a cylindrical shape and / or a first part having a cylindrical shape and a second part having a flared shape including a diverging wall.

7. The blade (18) according to claim 6, characterized in that The at least one first cooling hole has a cylindrical shape, and the ratio of the cross-sectional diameter of the first cooling hole to the radial dimension (e) of the rib (40) is strictly between 0.20 and 0.85, and / or the axial distance (l) of the at least one first cooling hole relative to the downstream end (40b) of the rib (40) and the axial distance (L) of the rib (40) between the upstream end (40a) and the downstream end (40b) have a ratio strictly between 0.1 and 0.

9.

8. The blade (18) according to claim 1 or 2, characterized in that The blade is a moving blade of a moving turbine wheel of a turbine.

9. The blade (18) according to claim 2, characterized in that The drilled hole has a circular and / or elliptical cross-sectional shape.

10. The blade (18) according to claim 2, characterized in that, The axis of the second cooling hole (41, 42) is arranged in an extension of the median axis (AA) of the at least one rib (40), which extends along the rib (40).

11. The blade (18) according to claim 3, characterized in that, The radial cross-sectional dimension is the diameter (d).

12. The blade (18) according to claim 1 or 2, characterized in that, The blade is a moving blade of a moving turbine wheel of a high-pressure turbine.

13. A turbine (7) for a turbine engine, characterized in that, The turbine comprises at least one moving wheel portion, and the at least one moving wheel portion comprises a plurality of blades (18) according to any one of claims 1 to 12.

14. The turbine (7) according to claim 13, characterized in that, The turbine is a high-pressure turbine.

15. A turbine engine (1), characterized in that, The turbine engine comprises at least one turbine (7) according to claim 13 or 14.

16. The turbine engine (1) according to claim 15, characterized in that, The turbine engine is a twin-spool turbine engine.

Images