Coolant distribution element and associated turbine ring assembly

Background of the invention

The invention relates to a turbine ring assembly comprising a plurality of ring sectors made of composite material with a ceramic matrix (CMC material) or of metallic material and more particularly relates to an element for distributing a cooling fluid.

The field of application of the invention is in particular that of gas turbine aero engines. The invention is however applicable to other turbomachines, for example industrial turbines.

In gas turbine aero engines, the improvement in efficiency and the reduction of certain polluting emissions lead to seeking operation at ever higher temperatures. In the case of entirely metal turbine ring assemblies, it is necessary to cool all the elements of the assembly and in particular the turbine ring which is subjected to very hot flows. Cooling a metal turbine ring requires the use of a large amount of cooling fluid, typically air, which has a significant impact on engine performance since the cooling flow used is taken from the engine. main motor flow.

The use of ring sectors made of CMC material has been proposed in order to limit the ventilation necessary for cooling the turbine ring and thus increase engine performance.

However, even if CMC ring sectors are used, it is still necessary to use a significant amount of coolant. The turbine ring is, in fact, faced with a hot source (the stream in which the flow of hot gas flows) and a cold source (the cavity delimited by the ring and the casing, hereinafter referred to as the expression "ring cavity"). The ring cavity must be at a pressure greater than that of the vein in order to prevent gas from the vein rising into this cavity and burning the metal parts. This overpressure is obtained by taking "cold" fluid from the compressor, which has not passed through the combustion chamber, and conveying it to the ring cavity. The upkeep

such an overpressure therefore makes it impossible to completely cut off the supply of “cold” fluid to the ring cavity.

In addition, studies carried out by the Applicant have shown that a ring, made of CMC or metallic material, cooled by known cooling systems can exhibit disadvantageous thermal gradients which generate unfavorable mechanical stresses. In addition, the cooling technologies used for a metal ring may not be easily transposable to a ring made of CMC material.

Whatever the nature of the material used for the ring sectors, it would therefore be desirable to improve the existing cooling systems in order to limit the unfavorable thermal gradients in the cooled ring sectors and therefore the generation of unfavorable stresses. It would also be desirable to improve the existing cooling systems in order to optimize the quantity of cooling fluid actually used for cooling the ring, in particular by limiting cooling fluid leaks.

The invention is specifically aimed at meeting the aforementioned needs.

Purpose and summary of the invention

To this end, the invention provides an element for distributing a cooling fluid intended to be fixed to a support structure for supplying cooling fluid to a wall to be cooled facing it, said distribution element comprising a body defining a internal volume for distributing the cooling fluid and a multi-perforated plate which delimits this internal volume and comprises a plurality of through outlet perforations which place said internal volume for distributing the cooling fluid with said wall to be cooled, the element distribution further comprising an inlet orifice opening into said internal volume for distributing the cooling fluid,characterized in that said internal coolant distribution volume comprises directional fins substantially equidistant from said inlet port and said multi-perforated plate, for directing coolant from said inlet port to said outlet perforations through.

The implementation, for each ring sector, of a cooling fluid distribution element, typically air, as described above has several advantages.

First of all, the directional fins make it possible to better distribute the supply of “fresh” air and therefore to cool the wall to be cooled uniformly, for example the ring sector placed downstream of the flow. Then, the cooling air being better channeled, unnecessary recirculation and pressure drops as well as associated heating of the cooling gas are limited. Finally, by also acting as construction pillars, the fins significantly simplify the manufacturing process by offering several possible construction orientations (and therefore geometries) and by limiting post-melting operations, in particular due to the fact that there is no no more supports to remove when building the internal volume using a powder bed laser fusion process.

Preferably, said body has a substantially pyramidal shape, a base of which is intended to receive said multi-perforated plate comprising said through outlet perforations diffusing the cooling fluid and of which the inclined faces meet at the top at the level of said inlet orifice of cooling air.

Advantageously, said directional fins are distributed regularly inside said internal volume.

Preferably, said directional fins have respective tops forming an arch providing support for a ceiling surface of said internal volume.

Advantageously, said directional fins comprise a central fin arranged in a central axis passing through the axis of said inlet orifice, at least two other fins being distributed identically on each side of said central fin with angles of inclination a and β by relative to said central axis going increasing.

Preferably, said first fin is inclined relative to said central axis in a range of the order of 30 to 44 ° and said second fin is inclined relative to said central axis in a range of the order of 45 to 59 ° .

Advantageously, said directional fins are in a number between 3 and 9.

The present invention also relates to a turbine ring assembly comprising a plurality of ring sectors forming a turbine ring, a ring support structure and a plurality of distribution elements as mentioned above as well as a turbomachine comprising such a turbine ring assembly.

The invention also relates to a method of laser melting on a powder bed for the manufacture of a distribution element as mentioned above, in which said directional fins act as a permanent support during the construction of said internal volume.

Brief description of the drawings

Other characteristics and advantages of the invention will emerge from the following description of particular embodiments of the invention, given by way of non-limiting examples, with reference to the appended drawings, in which:

- Figure 1 is a schematic exploded perspective view of a turbine ring assembly incorporating a cooling fluid distribution element according to the invention,

- Figure 2 is an end view, multi-perforated plate removed, of the coolant distribution element of Figure 1, and

- Figure 3 is a partial sectional view of the cooling fluid distribution element of Figure 1, and

- Figure 4 illustrates an example of a device for producing a distribution element.

Detailed description of embodiments

Figure 1 shows a schematic exploded perspective view of a portion of a high pressure turbine ring assembly comprising a turbine ring 11 of ceramic matrix composite (CMC) or metallic material and a metallic support structure ring 13. When the ring 11 is made of CMC, the ring support structure 13 is made of a material having a coefficient of thermal expansion greater than the coefficient of thermal expansion of the material constituting the ring sectors. The turbine ring 11 surrounds a set of rotating blades (not shown) and is formed of a plurality of ring sectors 110. The arrow D A indicates the axial direction of the turbine ring 11 while the arrow D Rindicates the radial direction of the turbine ring 11. The arrow D C indicates the circumferential direction of the turbine ring.

Each ring sector 110 has, along a plane defined by the axial D A and radial DR directions, a section substantially in the shape of the inverted Greek letter π. The sector 110 in fact comprises an annular base 112 and upstream and downstream radial hooking tabs 114 and 116. The terms “upstream” and “downstream” are used here with reference to the direction of flow of the gas flow in the turbine which is carried out along the axial direction D A .

The annular base 112 comprises, in the radial direction DR of the ring 11, an internal face 112a and an external face 112b opposite to each other. The internal face 112a of the annular base 112 is coated with a layer 113 of abradable material forming a thermal and environmental barrier and defines a gas stream flow stream in the turbine.

The upstream and downstream radial hooking tabs 114 and 116 extend projecting, in the direction D R , from the outer face 112b of the annular base 112 at a distance from the upstream and downstream ends 1121 and 1122 of the annular base 112. The upstream and downstream radial hooking tabs 114 and 116 extend over the entire circumferential length of the ring sector 110, that is to say over the entire arc of a circle described by the ring sector. 110.

The ring support structure 13 which is integral with a turbine housing 130 comprises a central ring 131, extending in the axial direction D A , and having an axis of revolution coincident with the rate of revolution of the ring of turbine 11 when fastened together. The ring support structure 13 further comprises an upstream annular radial flange 132 and a downstream annular radial flange 136 which extend, in the radial direction DR, from the central ring 31 towards the center of the ring 11 and in the circumferential direction of the ring 11.

The downstream annular radial flange 136 comprises a first free end 1361 and a second end 1362 integral with the central ring 131. The downstream annular radial flange 136 comprises a first portion 1363, a second portion 1364, and a third

portion 1365 between the first portion 1363 and the second portion 1364. The first portion 1363 extends between the first end 1361 and the third portion 1365, and the second portion 1364 extends between the third portion 1365 and the second end 1362 The first portion 1363 of the annular radial flange 136 is in contact with the downstream radial hooking tab 116. The second portion 1364 is thinned with respect to the first portion 1363 and the third portion 1365 so as to give a certain flexibility to the the annular radial flange 136 and thus do not over-stress the turbine ring 11.

The ring support structure 13 also comprises a first and a second upstream flange 133 and 134 each having, in the example illustrated, an annular shape. The two upstream flanges 133 and 134 are fixed together on the upstream annular radial flange 132. Alternatively, the first and second upstream flanges 133 and 134 could be segmented into a plurality of ring sections.

The first upstream flange 133 comprises a first free end 1331 and a second end 1332 in contact with the central ring 131. The first upstream flange 133 further comprises a first portion 1333 extending from the first end 1331, a second portion 1334 s 'extending from the second end 1332, and a third portion 1335 extending between the first portion 1333 and the second portion 1334.

The second upstream flange 134 comprises a first free end 1341 and a second end 1342 in contact with the central ring 131, as well as a first portion 1343 and a second portion 1344, the first portion 1343 extending between the first end 1341 and the second portion 1344, and the second portion 1344 extending between the first portion 1343 and the second end 1342.

The first portion 1333 of the first upstream flange 133 rests on the radial upstream hooking lug 114 of the ring sector 110. The first and second upstream flanges 133 and 134 are shaped to have the first portions 1333 and 1343 distant l ' one from the other and the second portions 1334 and 1344 in contact, the two flanges 133 and 134 being removably attached to the upstream annular radial flange 132 using screws 160 and nuts 161 for fixing, the screws 160 passing through orifices 13340, 13440 and 1320 provided respectively in the

second portions 1334 and 1344 of the two upstream flanges 133 and 134 as well as in the upstream annular radial flange 132. The nuts 161 are for their part integral with the ring support structure 13, being for example fixed by crimping thereto .

The second upstream flange 134 is dedicated to taking up the force of the high pressure distributor (DHP), on the one hand, by deforming, and, on the other hand, by passing this force towards the casing line which is more mechanically robust, i.e. towards the line of the ring support structure 13.

In the axial direction D A , the downstream annular radial flange 136 of the ring support structure 13 is separated from the first upstream flange 133 by a distance corresponding to the spacing of the upstream and downstream radial hooking tabs 114 and 116 so as to maintain the latter between the radial annular downstream flange 136 and the first upstream flange 133. It is possible to perform an axial prestressing of the flange 136. This makes it possible to take up the differences in expansion between the metal elements and the sectors of ring in CMC when these are used.

To further maintain in position the ring sectors 110, and therefore the turbine ring 11, with the ring support structure 13, the ring assembly comprises, in the example illustrated, two first pins 119 cooperating with the upstream hooking lug 114 and the first upstream flange 133, and two second pegs 120 cooperating with the downstream hooking lug 116 and the downstream annular radial flange 136.

For each corresponding ring sector 110, the third portion 1335 of the first upstream flange 133 comprises two orifices 13350 for receiving the two first pins 119, and the third portion 1365 of the annular radial flange 136 comprises two orifices 13650 configured to receive the two. second pawns 120.

For each ring sector 110, each of the upstream and downstream radial hooking tabs 114 and 116 comprises a first end, 1141 and 1161, integral with the outer face 112b of the annular base 112 and a second end, 1142 and 1162, free. The second end 1142 of the upstream radial hooking tab 114 comprises two first lugs 117 each comprising an orifice 1170 configured to receive a first pin 119. Similarly, the second end 1162 of

the downstream radial hooking lug 116 comprises two second ears 118 each comprising an orifice 1180 configured to receive a second pin 120. The first and second ears 117 and 118 projecting in the radial direction D R of the ring of turbine 11 respectively of the second end 1142 of the upstream radial attachment lug 114 and of the second end 1162 of the downstream radial attachment lug 116.

For each ring sector 110, the two first ears 117 are positioned at two different angular positions with respect to the axis of revolution of the turbine ring 11. Similarly, for each ring sector 110, the two seconds ears 118 are positioned at two different angular positions with respect to the axis of revolution of the turbine ring 11.

Each ring sector 110 further comprises rectilinear bearing surfaces 1110 mounted on the faces of the upstream and downstream radial hooking tabs 114 and 116 in contact respectively with the first upstream annular flange 133 and the downstream annular radial flange 136, that is to say on the upstream face 114a of the upstream radial attachment lug 114 and on the downstream face 116b of the downstream radial attachment lug 116. In a variant, the rectilinear supports could be mounted on the first upstream annular flange 133 and on the downstream annular radial flange 136.

The rectilinear supports 1110 make it possible to have controlled sealing zones. Indeed, the bearing surfaces 1110 between the upstream radial hooking tab 114 and the first upstream annular flange 133, on the one hand, and between the downstream radial hooking lug 116 and the downstream annular radial flange 136 are included in the same rectilinear plane.

More precisely, having supports on radial planes makes it possible to overcome the effects of bending in the turbine ring 11. Furthermore, the rings in operation tilt around a normal to the plane (D A , D R ). A curvilinear support would generate contact between the ring 11 and the ring support structure 13 at one or two points. Conversely, a rectilinear support allows a support on a line.

According to the invention, the ring assembly further comprises, for each ring sector 110, a cooling fluid distribution element 150. This distribution element 150 constitutes a fluid diffuser (typically air). allowing the impact of a cooling flow F Ron the external face 112b of the ring sector 110 (see FIG. 3). The element 150 is present in the space delimited between the turbine ring 11 and the ring support structure 13 and more particularly between the first upstream annular flange 133, the central ring 131 and the upstream radial hooking tabs and downstream 114 and 116. The distribution element 150 comprises a hollow body 151 which defines an internal volume for distributing the cooling air as well as a multi-perforated plate 152 which defines this internal volume and comprises a plurality of perforations. of through outputs 153A which place the internal volume of the hollow body 151 in communication with the space facing the external face 112b of the ring sector 110.

The hollow body 151 advantageously has a substantially pyramidal shape (that is to say progressive with an inlet narrower than the outlet), the base of which is intended to receive the multi-perforated plate 152 comprising the radial through-outlet perforations 153A and the inclined faces of which meet at the top at the level of an axial inlet opening for the cooling air 154 (illustrated in FIG. 3).

The multi-perforated plate 152 is located opposite (opposite) the external face 112b of the ring sector 110 and in the example illustrated has an elongated shape along the circumferential direction D cof the turbine ring 11. The multi-perforated plate 152 also comprises a plurality of lateral through outlet perforations 153B which emerge between the first 114 and second 116 hooking tabs of the ring sector 110. No third element n ' is present between the multi-perforated plate 152 and the outer face 112b of the ring sector 110 or the first 114 and second 116 hooking tabs so as not to slow down or disturb the flow of cooling air passing through the plate 152 and impacting the ring sector 110. The multi-perforated plate 152 which delimits the internal volume of the hollow body 151 is located on the side of the ring sector 110 (radially inward). The distribution element 150 further comprises a guide portion of theR and D in the axial direction A . The guide portion 155 is positioned radially outwardly relative to the multi-perforated plate 152. This guide portion 155 defines an interior channel (illustrated by the inlet orifice 154 of FIG. 3 which defines its outlet. ) which is in communication with the cooling air supply ports 192 and 190 respectively provided in the first 133 and second 134 upstream flanges.

The flow of cooling air F R taken upstream in the turbine is intended to pass through the orifices 190 and 192 with a view to being conveyed to the ring sector 110. The guide portion 155 defines the internal channel that the cooling air flow F Ris intended to pass through in order to be transferred to the internal volume of the hollow body 151 and to be distributed to the ring sector 110 following its passage through the ulti -perforated m plate 152. The internal channel has an inlet orifice (not visible in the figure) which is preferably located opposite (opposite and in contact) or in the extension (that is to say very little spaced from the first upstream flange 133) of the supply orifice 192 and communicating with the latter. The interior channel also opens into the internal volume through the inlet orifice 154 which emerges at the top of the pyramidal volume 151 at an end opposite to the multi-perforated plate 152. The interior channel of the guide portion 155 has role of channeling the cooling air F R arriving through the orifice 192 in order to transfer it to the interior volume and then to the ring sector 110 and thus to minimize the losses or leaks of this cooling air.

In order to ensure uniform cooling of the ring sector 110 and as illustrated in Figures 2 and 3, the interior pyramidal volume comprises directional fins 170, 172, 174, 176, 178, regularly distributed inside this volume and also acting as permanent manufacturing supports (pillars) allowing the construction of the ceiling surface 180, the side faces 182, 184 of the internal volume contributing, like the pillars, to guide the flow of cooling air and to maintain the ceiling surface during this construction.

Thus, the respective vertices 170A, 172A, 174A, 176A, 178A of the fins form a “vault” providing support for the ceiling surface 180 for which conventional support solutions do not work with such an area not accessible from the outside. . The pillars and the vault that they form at their top thus offer a permanent support solution that is more efficient than the supports.

conventional generics in terms of mass and aerodynamic performance and in addition making the geometry fully compatible with a powder bed laser fusion process.

In addition, by specifying individually each cooling hole (different surface hole sections, straight micro-perforation, with chamfer or with fillet, round, rhombic or any section, axis of holes orthogonal or inclined to the surface, distribution of hole position adjusted periodically or in any way) in any area of ​​the room (in flat area as well as in its side parts (leaves) a better distribution of the flow of fresh air serving to cool and homogenize the temperature of the sector is ensured The directional vanes allow a better distribution of the supply of "fresh" air and therefore homogeneous cooling of the ring sector placed downstream of the flow.central fin 170 is disposed in a central axis passing through the axis of the inlet orifice 154 substantially at an equal distance from this orifice and from the multi-perforated plate 152. The other fins are distributed identically on each side of this fin central preferentially with angles of inclination a and β with respect to the central axis increasing by approaching the side faces 182, 184. Thus, on either side of this central fin 170, a first fin is arranged 172, 174 inclined relative to the central axis in a range of the order of 30 ° to 44 ° and a second fin 176, 178 inclined in a range of the order of 45 ° to 59 °.The other fins are distributed identically on each side of this central fin preferentially with angles of inclination a and β with respect to the central axis which increases as they approach the lateral faces 182, 184. Thus, on both sides Another of this central fin 170, is disposed a first fin 172, 174 inclined relative to the central axis in a range of the order of 30 ° to 44 ° and a second fin 176, 178 inclined in a range of the order of 45 ° to 59 °.The other fins are distributed identically on each side of this central fin preferentially with angles of inclination a and β with respect to the central axis which increases as they approach the lateral faces 182, 184. Thus, on both sides Another of this central fin 170, is disposed a first fin 172, 174 inclined relative to the central axis in a range of the order of 30 ° to 44 ° and a second fin 176, 178 inclined in a range of the order of 45 ° to 59 °.is disposed a first fin 172, 174 inclined relative to the central axis in a range of the order of 30 ° to 44 ° and a second fin 176, 178 inclined in a range of the order of 45 ° to 59 ° .is arranged a first fin 172, 174 inclined relative to the central axis in a range of the order of 30 ° to 44 ° and a second fin 176, 178 inclined in a range of the order of 45 ° to 59 ° .

It will be noted that if these fins have been defined by a single angle, and can therefore be qualified as straight, it is of course possible, depending on the desired air flow deviation, to make a more complex geometry, specific to the image of turbine blades with inclinations and curvatures having a different angle upstream and downstream. Likewise, depending on the desired homogeneous air distribution or not, the central fin may or may not be present. Of course, the number of directional fins cannot be limiting and is advantageously between 3 and 9.

The guide portion 155 also defines a through housing 156, in the present case, but which could alternatively be blind and of which a fixing screw 163 intended to cooperate with this housing 156 secures the fixing of the distribution element 150 to the ring support structure 13. As can be seen in particular in Figure 1, the distribution element 150 comprises, in the example illustrated, an additional holding portion 157 separate from the guide portion 155 (the portion 157 not necessarily having an internal channel for conveying the cooling fluid which will then have to pass through an internal wall 186 open between these two portions). The portions 155 and 157 of the same distribution element 150 are offset along the circumferential direction D c. The retaining portion 157 also defines a housing 158 cooperating with a fixing screw 163 in order to allow the element 150 to be fixed to the ring support structure 13. In the example illustrated, the fixing screws 163 s 'extend along the axial direction D A of the turbine ring and pass through the first 133 and second 134 upstream flanges when they are housed in the housings 156 and 158.

We now describe a method of making a turbine ring assembly corresponding to that shown in Figure 1.

When the ring sectors 110 are made of CMC material, the latter are made by forming a fiber preform having a shape close to that of the ring sector and densifying the ring sector with a ceramic matrix.

To produce the fiber preform, one can use ceramic fiber threads, for example SiC fiber threads such as those sold by the Japanese company Nippon Carbon under the name "Hi-Nicalon S", or fiber threads of carbon.

The fiber preform is advantageously produced by three-dimensional weaving, or multi-layer weaving with provision of unbinding zones making it possible to separate the parts of the preforms corresponding to the tabs 114 and 116 of the sectors 110.

The weaving can be of the interlock type, as illustrated. Other three-dimensional or multi-layer weaves can be used, for example multi-plain or multi-satin weaves. Reference may be made to document WO 2006/136755.

After weaving, the blank can be shaped to obtain a ring sector preform which is consolidated and densified by a ceramic matrix, the densification being able to be carried out in particular by

chemical gas infiltration (CVI) which is well known per se. In a variant, the textile preform can be hardened a little by CVI so that it is sufficiently rigid to be handled, before making liquid silicon rise by capillary action in the textile in order to make the densification.

A detailed example of the manufacture of ring sectors in CMC is described in particular in document US 2012/0027572.

When the ring sectors 110 are made of a metallic material, the latter can for example be formed by one of the following materials: AMI alloy, C263 alloy or M509 alloy.

The ring support structure 13 is for its part made of a metallic material such as a Waspaloy® or Inconel 718 or even C263 alloy.

As shown in Figure 4, the distribution element 150 is advantageously produced by a powder bed laser melting process (LBM for Laser Beam Melting) which guarantees better geometric precision and a reduction in the air gap with the ring. due to a one-piece design. The LBM process by reducing the overall volume of supports, the surfaces to be used in machining, or the size of the production plate, allows to obtain a significant reduction in manufacturing costs by reducing the mass (low thickness) while providing an improvement in terms of performance (cooling, lightness).

By vertical positioning of the perforated wall 152 on the manufacturing platform 194, better control of its geometry is ensured while reducing its level of roughness (both mechanical and aerodynamic benefit). In addition, by making the construction pillars functional and permanent (1 fin = 1 construction pillar), a geometry is thus created which optimizes the cooling function while supporting the ceiling surface, thus ensuring better manufacturability and this without penalizing the mass.

The production of the turbine ring assembly continues with the mounting of the ring sectors 110 on the ring support structure 13. This assembly can be carried out ring sector by ring sector as follows. .

The first pins 119 are first placed in the orifices 13350 provided in the third part 1335 of the first upstream flange 133, and the ring sector 110 is mounted on the first upstream flange 133 by engaging the first pins 119 in the orifices 1170 the first ears of the upstream hooking lug 114 until the first portion 1333 of the first upstream flange 133 bears against the bearing surface 1110 of the upstream face 114a of the upstream hooking lug 114 of the sector ring 110.

The second upstream flange 134 is then fixed to the first upstream flange 133 and to the distribution element 150 present between the tabs 114 and 116 by positioning the fixing screws 163 through the orifices 13440, 13340, 154 and 158.

Then the two second pins 120 are inserted into the two orifices 13650 provided in the third part 1365 of the annular radial flange 136 of the ring support structure 13.

The assembly comprising the ring sector 110, the flanges 133 and 134 and the distribution element 150 previously obtained is then mounted on the ring support structure 13 by inserting each second pin 120 into each of the orifices 1180 of the seconds. lugs 118 of the downstream radial hooking tabs 116 of the ring sector 110. During this assembly, the second portion 1334 of the first upstream flange 133 is placed against the upstream annular radial flange 132.

The assembly of the ring sector is then finalized by inserting the fixing screws 160 in the openings 13440, 13340 still free and 1320, coaxial, and each of the screws is tightened in the nuts 161 integral with the ring support structure .

The exemplary embodiment which has just been described comprises, for each ring sector 110, two first pins 119 and two second pins 120. However, it does not depart from the scope of the invention if for each ring sector, two first pawns 119 and a single second pawn 120 or a single first pawn 119 and two second pawns 120 are used.

In a variant not shown, one could also use a distribution element 150 having the same structure as that described in Figure 1 and pins extending in the radial direction between the central ring 131 and the hooking tabs 114 and 116 in order to maintain these legs in a radial position. According to this variant, the ends of these pins are inserted by force into orifices made in the central ring 131 in order to ensure their retention. As a variant, these pins could be mounted with play in the orifices of the central crown 131 and then be welded.

It will be noted that if the aforementioned description is essentially concerned with a distribution element for turbine ring sectors, it is clear that such a shower-type distribution element can also find application in all other engine components, for example. example of walls or surfaces to be cooled, requiring a cooling air supply such as a housing.
CLAIMS

1. Element for distributing a cooling fluid (150) intended to be fixed to a support structure (13) for supplying cooling fluid to a wall to be cooled (110) facing it, said distribution element comprising a body. (151) defining an internal volume for distributing the cooling fluid and a multi-perforated plate (152) which delimits this internal volume and comprises a plurality of through outlet perforations (153A, 153B) which place said internal distribution volume in communication cooling fluid with said wall to be cooled (110), the distribution element comprising an inlet orifice (154) opening into said internal volume for distributing the cooling fluid,characterized in that said internal coolant distribution volume includes directional fins (170, 172, 174, 176, 178) disposed substantially equidistant from said inlet port and said multi-perforated plate, to direct the fluid cooling said inlet port to said through outlet perforations.

2. Distribution element according to claim 1, characterized in that said body has a substantially pyramidal shape, a base of which is intended to receive said multi-perforated plate comprising said through outlet perforations diffusing the cooling fluid and whose inclined faces are meet at a top at said cooling air inlet port.

3. Distribution element according to claim 1 or claim 2, characterized in that said directional fins are regularly distributed inside said internal volume.

4. Distribution element according to any one of claims 1 to 3, characterized in that said directional fins have respective vertices (170A, 172A, 174A, 176A, 178A) forming an arch providing support for a ceiling surface. (180) of said internal volume.

5. Distribution element according to any one of claims 1 to 4, characterized in that said directional fins comprise a central fin (170) disposed in a central axis passing through the axis of said inlet orifice, at least two others fins (172, 174; 176, 178) being distributed identically on each side of said central fin with angles of inclination a and β with respect to said central axis going increasing.

6. Distribution element according to claim 5, characterized in that said first fin is inclined relative to said central axis in a range of the order of 30 ° to 44 ° and said second fin is inclined relative to said central axis. in a range of the order of 45 ° to 59 °.

7. Distribution element according to any one of claims 1 to 6, characterized in that said directional fins are in a number between 3 and 9.

8. Turbine ring assembly for a turbomachine comprising a plurality of ring sectors (110) forming a turbine ring, a ring support structure (13) and a plurality of distribution elements (150) along the line. any one of claims 1 to 7.

9. A turbomachine comprising a turbine ring assembly according to claim 8.

10. A method of laser melting on a powder bed for the manufacture of a distribution element according to any one of claims 1 to 7, wherein said directional fins function as a permanent support during the construction of said internal volume.