0001] The present disclosure relates to a blade, for example a turbine blade that can be used in an aircraft turbine engine, and more particularly the internal cooling of such a blade.

BACKGROUND

[0002] An aircraft turbomachine usually comprises a combustion chamber, the combustion gas drive in rotation one or more turbines. To protect the turbine blades of the high temperatures to which they are thus subjected, in particular the blades, it is known to provide the blades are hollow so as to circulate inside the blades of a cooling fluid, e.g. the relatively cold air taken upstream of the combustion chamber.

[0003] The international application WO 2015/162389 Al of the Applicant describes a turbomachine turbine vane comprising an improved homogeneity in cooling circuit. In particular, the blade has a plurality of recesses in the thickness of the blade.

[0004] However, the increased performance requirements lead to increase the efficiency of the turbomachine, and hence to increase the temperature of the combustion gases passing through the turbine without increasing the coolant flow inside the blades. Thus, although the aforementioned blade has satisfactory results, there is a need for even more resistant to high temperatures dawn.

PRESENTATION OF THE INVENTION

[0005] To this end, the present disclosure relates to a turbine blade comprising a blade root end defining a radially

internal of the blade and a blade extending radially outwardly from the blade root and having a pressure wall and a suction side wall connected to the pressure side wall at a leading edge and a trailing edge of the blade, the blade comprising at least a first internal cooling circuit having at least one concave cavity radially extending along the pressure side wall and a first inner wall arranged between the wall intrados and extrados wall, at least one suction recess extending radially along the upper wall and a second inner wall, arranged between the pressure side wall and the wall suction , thevane being characterized in that the first cooling system further comprises at least one through inner cavity defined between two through walls each extending between the pressure side wall and the suction wall, away from the leading edge and the trailing edge, the radially through inner cavity extending along the pressure wall and suction wall, wherein the cavity pressure face, the convex side cavity and through inner cavity are fluidly connected serial.intrados and extrados of the wall, wherein the cavity pressure side, the suction cavity and through inner cavity are fluidly connected in series.intrados and extrados of the wall, wherein the cavity pressure side, the suction cavity and through inner cavity are fluidly connected in series.

[0006] In the present specification, unless otherwise specified, the upstream and downstream are defined with respect to the normal direction of flow of gas (upstream to downstream) through the turbomachine. The upstream and downstream are used relative to the gas flowing outside of the blade, usually the leading edge towards the trailing edge, and not the cooling fluid circulating within the dawn. For brevity and without loss of generality, we either talk later, coolant or simply air.

[0007] Moreover, so-called axis of the turbine, the axis of rotation of the rotor of the turbine. The axial direction corresponds to the direction of the axis of the turbine and a radial direction, wherein the blade extends, is a direction perpendicular to said axis and intersecting said axis. Thus, the radial direction corresponds to the longitudinal direction of the blade. Similarly, a

axial plane is a plane containing the axis of the turbine and a radial plane is a plane perpendicular to this axis. A transverse plane is a plane orthogonal to the radial or longitudinal direction. A circumference is defined as a circle belonging to a radial plane and whose center is located in the axis of the turbine. A tangential or circumferential direction is a direction tangent to a circumference; it is perpendicular to the compressor axis, but does not pass through the axis.

[0008] For the purposes of the present disclosure, a cavity radially extends along a wall if the cavity is adjacent to the wall on at least half of its length, preferably substantially throughout its length in a radial direction. Furthermore, a cavity is considered distinct from another cavity so these two cavities are separated by a wall on at least half the length of the blade in a radial direction, preferably substantially the entire length of the blade.

[0009] Thanks to the presence of the through inner cavity as defined above, the through walls have a freedom of deformation to accommodate the differential expansion between the outer portions of the blade, such as the walls of intrados and extrados , relatively warm, and the inner portions of the blade, such that the first and second internal walls, relatively cold. Thus, the internal structure of the blade is relaxed, which limits the occurrence of stresses in the blade and, consequently, increases its resistance to temperature differences and longevity. The fact that the cavity pressure side, the suction cavity and through inner cavity are fluidly connected in series also maximizes the coolant labor and

[0010] The second internal wall may be separate or merged with the first inner wall. In the case where the second inner wall is merged with the first inner wall, the cavity pressure face and suction cavity are adjacent. In these embodiments, the direction of cooling air flow may undergo a reversal between the cavity pressure face and the suction cavity in the thickness of the blade. The thickness of the blade indicates a direction perpendicular to a median line between the pressure side wall and the wall suction in a transverse plane.

[0011] In addition, the first inner wall and the second inner wall may each be connected to one of said walls therethrough; the first and second inner walls may then be connected to the same through-wall or through-distinct walls.

[0012] In some embodiments, the cavity pressure side, the suction cavity and through inner cavity are fluidly connected in this order. The fact of connecting said cavities in the order mentioned above makes it possible to further optimize the working of the air to a moving blade. Indeed, due to the rotation of the blading, the Coriolis force cooling air plate along the walls intrados or extrados of the blade, depending on whether the air flow is upward or downward within of the blade. The above sequence allows to press the air against the pressure side wall into the cavity and against the pressure face wall in the suction cavity suction and then again against the pressure side wall in the through inner cavity . Thus, the air interaction with the walls of intrados and extrados is maximized while the interaction of the air with the inner walls is limited, allowing respectively and concomitantly improve the cooling of the intrados wall and suction and limit the thermal gradient in the blade, between the walls of intrados and extrados of the one part and the other inner walls. In addition, as will be detailed subsequently, the mechanical properties of the pressure side wall, the wall suction and internal walls may depend on the temperature; in particular, the mechanical properties may be substantially constant up to a threshold temperature, then gradually degrade above the threshold temperature. So,

[0013] In some embodiments, the cavity intrados and / or extrados cavity has a decreasing cross section in the radial direction. Preferably, the lower surface of cavity may have a decreasing cross-section of the radially inner end of the blade towards the radially outer end of the blade. Alternatively or additionally, the suction cavity may have a decreasing cross section the radially outer end of the blade towards the radially inner end of the blade. The fact that the cavities intrados and / or extrados are radially convergent improves the flow into the recesses and serves to limit, if not avoid recirculation eddies. Further, when cavity pressure face and a recess of extrados adjacent to both sides of the same inner wall, tilt the inner wall which separates them, with respect to the radial direction, allows to obtain the above structurally simple configuration, and that these cavities are in fluid communication or not. In addition, this configuration is facilitated by the weak interaction of the air with the inner walls, especially when the air is pressed against the pressure side wall into the cavity and against the pressure face wall in the suction cavity suction. and that these recesses are in fluid communication or not. In addition, this configuration is facilitated by the weak interaction of the air with the inner walls, especially when the air is pressed against the pressure side wall into the cavity and against the pressure face wall in the suction cavity suction. and that these recesses are in fluid communication or not. In addition, this configuration is facilitated by the weak interaction of the air with the inner walls, especially when the air is pressed against the pressure side wall into the cavity and against the pressure face wall in the suction cavity suction.

[0014] In some embodiments, the first internal wall is connected to a first of said walls therethrough and the second inner wall is connected to a second of said walls therethrough. The first through-wall is distinct from the second through-wall. It follows that the first inner wall and the second inner wall are distinct. The cavities intrados and extrados are thus arranged on either side of the through inner cavity.

[0015] In some embodiments, the blade includes a third through-wall connected to the first internal wall or the second inner wall, the internal cooling circuit having a second through-going cavity extending radially along the wall soffit, wall suction and third through-wall. The second through-going cavity may be internal, that is to say extend away from the leading edge or the trailing edge, or be defined between the third through-wall and the walls intrados and extrados joining the leading edge or trailing edge. The presence of the second through-going cavity allows further softening the internal structure of the blade.

[0016] In some embodiments, the third through-wall being connected to the first inner wall (the second inner wall, respectively), the cavity pressure face (cavity respectively extrados) is adjacent to the first through-going cavity and the second through-going cavity. Thus, the first and second through holes may be provided on either side of the cavity pressure side (suction cavity respectively). In these embodiments, the first and second through holes are separated by a single cavity pressure side (suction cavity respectively) which extends radially along the first through-going cavity of the second through-going cavity of the first inner wall (respectively of the second inner wall) and the wall of

[0017] In some embodiments, the cavity of the intrados and extrados cavity are formed on either side of the through inner cavity and a passage fluidly connecting the cavity to the suction pressure side cavity without pass through the through inner cavity. The upper cavity may in turn be fluidly connected to the through internal cavity. In these embodiments, the cavity pressure side, the suction cavity and through inner cavity are formed paperclip winding on itself. Said passage is preferably located at the radially outer end of the blade.

[0018] In some embodiments, the concave cavity is formed of the trailing edge side and the convex side cavity of the edge of the leading side with respect to the through inner cavity. Thus, cooling air flows between the cavity pressure face and the suction cavity, the trailing edge towards the leading edge, that is to say, against the current of air driving the turbine. The cooling air, relatively cool, may optionally be removed from the blade toward the edge, where it flows downstream along the blade and forms a protective cooling layer by a fluid film that will be described later.

[0019] In some embodiments, the first internal wall and the second inner wall are each delimited by two through walls, each through-wall extending between the pressure side wall and the wall suction. Each inner wall delimited by two through walls may define an internal structure in the general shape of H. Thus, in these embodiments, the blade comprises an inner structure in the general shape of a double H, the side bars being the through walls. It is possible, similarly, to consider an internal structure in the general form of Triple H, or four or more, with many walls and internal walls traversing needed. Two successive through-walls, if they are not connected by the first or second inner wall,

[0020] In some embodiments, the wall of this lower surface at least one opening, preferably a plurality of openings connecting the through inner cavity to outside of the blade. This aperture may act, optionally in combination with other similar or different ports, air outlet to the through inner cavity. The orifice allows to discharge, along the pressure side wall, the air having flowed through the through inner cavity. This forms a protective layer by cooling a fluid film, better known by the English name "film cooling", which helps to reduce not only the temperature of the pressure side wall but also global cooling air in the cavities, which s' is particularly advantageous when the cavity pressure side is on the side of the trailing edge relative to the through internal cavity. Optionally, the hole can be directed to the trailing edge, which improves regularity of air flow and strengthens the protective layer.

[0021] In some embodiments, the blade comprises a second identical internal cooling system to the internal cooling circuit, in particular wherein the first inner wall of the first internal cooling circuit is merged with the second inner wall of the second circuit internal cooling.

radially extending along the pressure wall and suction wall, wherein the cavity pressure side, the suction cavity and through inner cavity are fluidly connected in series. Optionally, the second internal cooling circuit may have all or part of other

detailed features about the first internal cooling circuit.

[0023] Furthermore, this configuration may be provided repeatedly: thus, some embodiments comprise a third identical internal cooling circuit in the second internal cooling circuit, in particular wherein the first inner wall of the second internal cooling circuit is confused with the second inner wall of the third internal cooling circuit. So on, several other internal cooling circuits may be provided according to the same pattern.

[0024] In some embodiments, the blade comprises a radially outer end to its bath, and the first internal cooling circuit comprises an auxiliary convex side cavity extending radially along the upper wall and configured to supplying a cooling cavity of the tub, generally disposed under the tub. A bathtub is a cavity in the tip of the blade, that is to say at its radially outer end, open towards said end and delimited by a bottom wall and a flange, said flange extending between the leading edge and the trailing edge. The cooling cavity of the tub intended to improve the blade cooling head, which is traditionally a hot spot of the blade during operation,

[0025] In some embodiments, the blade comprises a leading edge cooling circuit comprising an upstream cavity radially extending along the pressure side wall and the suction side wall and adjacent the edge of attack, and a first supply cavity fluidly connected to the upstream cavity to the cooling air supply. Due to the fact that the feed of the upstream cavity is indirect, via the first supply cavity, air still relatively fresh, with little worked, can be provided to the radially outer end of the upstream cavity, which improves the cooling at the leading edge blade head. The fluid connection between the upstream cavity and the first cavity of supply can be carried out by an impact device. Such an impact device may comprise a plurality of channels. These channels may be of small section in relation to the size of the cavity and / or substantially radially disposed. These channels can be configured to accelerate the air passing therethrough, thereby forming a jet that impacts the opposite wall, by the wall of the upstream cavity, and thus improving heat transfer locally.

[0026] In some embodiments, the blade comprises a trailing edge cooling circuit comprising a downstream cavity radially extending along the pressure wall and suction wall and adjacent to the trailing edge, and a second supply cavity fluidly connected to the downstream cavity for cooling air supply. Due to the fact that the supply of the downstream cavity is indirect, via the second supply cavity, air still relatively fresh, with little worked, can be provided to the radially outer end of the downstream cavity, which improves the cooling at the trailing edge of the blade head. The fluid connection between the downstream cavity and the second cavity of supply can be performed by a plurality of holes provided on substantially the entire length in the radial direction, a wall separating the cavity downstream of the second supply cavity. Such a plurality of holes is sometimes called "calibration".

[0027] The present disclosure further relates to a turbine blade comprising a blade root defining a radially inner end of the blade and a blade extending radially outwardly from the blade root and having a pressure side wall and a wall

between the first through-wall and the second through-wall, a concave side cavity extending radially along the pressure side wall, the inner wall and second and third through-walls, a cavity extrados extending radially along the extrados wall, the inner wall and second and third through-walls, and a second radially through inner cavity extending along the pressure wall and suction wall, between the third through-wall and the fourth through-wall. Such a blade may have all or part of the previously described characteristics. the inner wall and the second and third walls therethrough, a suction side cavity extending radially along the upper wall, the inner wall and second and third through-walls, and a second through inner cavity s' radially extending along the pressure wall and suction wall, between the third and fourth through-wall through-wall. Such a blade may have all or part of the previously described characteristics. the inner wall and the second and third walls therethrough, a suction side cavity extending radially along the upper wall, the inner wall and second and third through-walls, and a second through inner cavity s' radially extending along the pressure wall and suction wall, between the third and fourth through-wall through-wall. Such a blade may have all or part of the previously described characteristics. between the third and fourth through-wall through-wall. Such a blade may have all or part of the previously described characteristics. between the third and fourth through-wall through-wall. Such a blade may have all or part of the previously described characteristics.

[0028] The present disclosure also relates to a turbomachine including a blade as described above. The term "turbomachine" refers to all gas turbine apparatus producing motive power, among which are in particular jet engines providing a thrust required for propulsion by reaction in the high-speed ejection of hot gases, and turboshaft in which the motive power is provided by the rotation of a motor shaft. For example, turbine engines are used as engine for helicopters, ships, trains, or as engine

industrial. The turbo (turbine engine driving a propeller) are also used as turbine aircraft engine.

BRIEF DESCRIPTION OF DRAWINGS

[0029] The invention and its advantages will be better understood by reading the following detailed description, embodiments of the invention given as non-limiting examples. This description refers to the accompanying drawings, wherein:

- Figure 1 shows a perspective view of a turbine blade according to a first embodiment;

- Figure 2 shows the blade according to the first embodiment in section on the plane II-II of Figure 1;

- Figure 3 shows the blade according to the first embodiment in section on the plane III-III of Figure 1;

- Figure 4 shows the blade according to the first embodiment in section on the plane IV-IV of Figure 1;

- Figure 5 shows the blade according to the first embodiment in section on the plane VV of Figure 1;

- Figure 6 shows the blade according to the first embodiment in section on the plane VI-VI of Figure 1;

- Figure 7 is a diagram summarizing the flow of a cooling fluid inside of the blade according to the first embodiment;

- Figure 8 shows schematically the deformation of the blade according to the first embodiment, in use, in section on the plane III-III of Figure 1;

- Figure 9 shows the blade according to the first embodiment in section on the plane IX-IX of Figure 1;

- Figure 10 is a diagram summarizing the flow of a cooling fluid inside a blade according a second embodiment;

- Figure 11 is a diagram summarizing the flow of a cooling fluid inside a blade according a third embodiment;

- Figure 12 is a diagram summarizing the flow of a cooling fluid inside a blade according a fourth embodiment;

- Figure 13 is a partial schematic view of a turbomachine incorporating cutting blade according to one of the embodiments.

DETAILED DESCRIPTION OF THE INVENTION

[0030] In Figure 1 is shown, in perspective, an example of a hollow rotor blade 10 for a gas turbine according to a first embodiment. Of cooling air (not shown) flows inside of the blade from the bottom of the foot 12 of the blade in the blade 13, along the longitudinal direction RR 'of the blade 13 (direction vertical in the figure and radial direction relative to the axis XX 'of rotation of the rotor), towards the head 14 of the blade (at the top in Figure 1) and this cooling air escapes through an outlet for join the main gas stream. The base 12 forms the radially inner end of the blade 10 and the head 14 forms the radially outer end of the blade 10.

[0031] In particular, the cooling air flows in an internal cooling circuit which is located inside the blade 13 and some of which branches lead to the head 14 of the blade at through holes 15 provided in a bathtub.

[0032] The body of the blade is profiled so that it defines a pressure side wall 16 and an extrados wall 18. The pressure side wall 16 has a generally concave shape and is in the first face to the flow of hot gases, that is to say the pressure side of the gas, by its outer face, facing upstream. The suction wall 18 is convex and has subsequently to hot gas stream, that is to say on the suction side of the gas along its outer side facing downstream.

[0033] Les parois d'intrados 16 et d'extrados 18 se rejoignent à l'emplacement du bord d'attaque 20 et à l'emplacement du bord de fuite 22 qui s'étendent radialement entre la tête 14 de l'aube et le haut du pied 12 de l'aube.

[0034] Comme indiqué précédemment, la pale 13 comprend un premier circuit de refroidissement interne qui va être détaillé en référence aux figures 2 à 9. En particulier, les figures 2 à 6 présentent des sections successives de l'extrémité radialement interne de la pale 13 à son extrémité radialement externe.

[0035] La figure 3 représente la pale 13 en section selon un plan transversal. Le plan III-III est situé de préférence entre 10% et 90% de la dimension de la pale 13 dans la direction longitudinale, de préférence entre 20% et 80%, de préférence encore entre 25% et 75%.

[0036] Comme illustré sur la figure 3, l'aube comprend des cavités 31-41 séparées les unes des autres par des parois s'étendant radialement. Plus particulièrement, l'aube 10 comprend des parois traversantes s'étendant chacune entre la paroi d'intrados 16 et la paroi d'extrados 18, à distance du bord d'attaque 20 et du bord de fuite 22. Dans ce mode de réalisation, l'aube comprend sept parois traversantes 51, 53, 55, 57, 59, 61, 63. Comme illustré, les parois traversantes peuvent être sensiblement rectilignes en section transversale.

[0037] Par ailleurs, l'aube 10 comprend des parois internes agencée chacune entre la paroi d'intrados 16 et la paroi d'extrados 18 et à distance de la paroi d'intrados 16 et de la paroi d'extrados 18, en l'occurrence trois parois internes 43, 45, 47. Comme illustré, les parois internes peuvent être sensiblement rectilignes en section transversale.

[0038] Les parois internes relient deux à deux les parois traversantes de façon à former des structures en forme générale de H. Plus précisément, dans ce mode de réalisation, la paroi interne 43 relie les parois traversantes 51 et 53, la paroi interne 45 relie les parois

traversantes 55 et 57, et la paroi interne 47 relie les parois traversantes 59 et 61, ce par quoi trois structures en forme générale de H sont formées, lesdites trois structures n'étant reliées les unes aux autres que par les parois d'intrados et d'extrados 16, 18.

[0039] Comme illustré sur la figure 3, les structures en forme générale de H précitées sont séparées, deux à deux, par une cavité interne traversante. Ainsi, dans ce mode de réalisation, l'aube 10 comprend deux cavités internes traversantes 35, 38. La cavité interne traversante 35 (respectivement la cavité interne traversante 38) est définie entre deux parois traversantes 57, 59 (respectivement deux parois traversantes 53, 55) appartenant à des structures en H distinctes et s'étend radialement le long de la paroi d'intrados 16 et de la paroi d'extrados 18.

[0040] Thus, the pressure side wall 16, the suction wall 18, the inner walls 43, 45, 47 and the through walls 51, 53, 55, 57, 59, 61, 63 define a plurality of cavities, the characteristics and role will now be detailed.

[0041] An upstream cavity 31 radially extends along the pressure side wall 16 and the suction wall 18 and is defined by a through wall 51. The cavity 31 is adjacent the upstream edge 20.

[0042] A first supply cavity 32 is defined between the pressure side wall 16, the through wall 51, inner wall 43 and the through wall 53. To the extent that it radially extends along the wall of intrados 16 and an inner wall, the first supply cavity 32 may also be called pressure side cavity. The first supply cavity 32 is fluidly connected to the upstream cavity 31 for cooling air supply, for example by an impact device as defined above. The first supply cavity 32 may be, in turn, supplied with cooling air via an air inlet section formed in the blade root 12, for example a channel.

[0043] The upper cavity 31 and the first supply cavity 32 form an edge cooling circuit for cooling of attack of the blade 13 at its leading edge 20.

[0044] Similarly, a downstream cavity 40 radially extends along the pressure side wall 16 and the suction wall 18 and is defined by a through wall 63. The cavity 40 is adjacent the downstream edge 22 leak.

[0045] A second supply cavity 39 is defined between the pressure side wall 16, the through wall 61, the suction wall 18 and the through wall 63. The second supply cavity 39 is fluidly connected to the cavity downstream 40 for cooling air supply, for example by a calibration as previously defined. The second supply cavity 39 may be, in turn, supplied with cooling air via an air inlet section formed in the blade root 12, for example a channel.

[0046] The downstream cavity 40 and the second supply cavity 39 form an edge cooling circuit leakage for cooling of the blade 13 at its trailing edge 22.

[0047] The blade 13 further comprises a first internal cooling circuit comprising at least one cavity pressure face, which in this case may be selected from two cavities pressure face 33, 36. The cavity 33 pressure face (resp . intrados of the cavity 36) radially extends along the pressure side wall 16 and an inner wall 47 (resp. an inner wall 45) arranged between the pressure side wall 16 and the wall suction 18. Said inner wall 47 (resp. the inner wall 45) defining the cavity 33 pressure face (resp. intrados of the cavity 36) may be described as first inner wall. Furthermore, of the cavity lower surface 33 (resp. Intrados of the cavity 36) is defined by the through-walls 59, 61 (resp. The through walls 55, 57), the first inner wall 47 (resp.

The second inner wall may be separate or merged with the first inner wall mentioned above. In the case where the first inner wall and the second internal wall are combined, the cavities intrados and corresponding suction can be located on either side of said first and second inner wall. For example, it may be of the cavity pressure face 33 of the suction cavity 34 and internal wall 47. Conversely, in the case where the first and second inner walls are separate, the cavities intrados and corresponding suction are not located on either side of the same inner wall. This example can be illustrated by the cavity pressure face 36 defined by the first inner wall 45 and the cavity of

[0049] Moreover, the cavity pressure face 37 (resp. The suction cavity 41, resp. The upper surface of cavity 34) is defined by the through walls 51, 53 (resp. The through walls 55, 57, resp. the through walls 59, 61), the second inner wall 43 (resp. the second inner wall 45, resp. the second inner wall 47) being connected to said walls

through-51, 53 (resp. therethrough to said walls 55, 57, resp. therethrough to said walls 59, 61).

[0050] Furthermore, the first cooling system further comprises at least one through inner cavity, in this case which can be selected from three internal through cavities 38, 35, 39. The through inner cavity 38 (resp. 35, resp. 39) is defined between two walls through-51, 53 (resp. 55, 57, resp. 59, 61) and radially extends along the pressure side wall 16 and the suction wall 18.

[0051] Thus, in this first embodiment, it can be identified a first internal cooling circuit comprising at least one cavity pressure face 33 radially extending along the pressure side wall 16 and a first wall internal 47 arranged between the pressure side wall 16 and the wall suction face 18, at least one suction cavity 34 extending radially along the upper wall 18 and a second internal wall 47 arranged between the pressure wall 16 and the wall suction face 18, and in this case coincides with the first internal wall, the first cooling circuit further comprising at least one through inner cavity 35 defined between two walls of the through 57, 59 s' each extending between the pressure side wall 16 and the wall suction face 18,away from the leading edge 20 and trailing edge 22, the through inner cavity 35 extending radially along the pressure side wall 16 and the suction wall 18. The first inner wall 47 (and therefore the second inner wall) is connected to one of said walls therethrough, namely the through wall 59.

[0052] In this embodiment, the blade 13 comprises a further first internal cooling circuit comprising at least one cavity pressure face 36 radially extending along the pressure side wall 16 and a first inner wall 45 arranged between the pressure side wall 16 and the wall suction face 18, at least one suction cavity 37 extending radially along the upper wall 18 and a second wall

internal 43, arranged between the pressure side wall 16 and the wall suction face 18, the first cooling system further comprising at least one through inner cavity 38 defined between two through walls 53, 55 each extending between the wall intrados 16 and extrados wall 18, away from the leading edge 20 and trailing edge 22, the through inner cavity 38 extending radially along the pressure side wall 16 and the wall of upper surface 18. the first internal wall 45 and the second inner wall 43 are each connected to one of said walls traversing, namely respectively connected to the through walls 53, 55.

[0053] Figure 2 illustrates a section of the blade 13 radially more inwardly than the section of Figure 3 (see Figure 1). As illustrated in Figure 2, radially inner portion of the blade, a passageway 53a is formed in the through wall 53 so as to fluidly connect the cavity 37 to the suction through inner cavity 38. Moreover, a passageway 59a is formed in the through wall 59 so as to fluidly connect the cavity 34 to the suction through inner cavity 35. Thus, the upper surface of cavity 34 (resp. of the upper cavity 37) and through inner cavity 35 (resp . the through inner cavity 38) are fluidly connected in series, as shown by the arrows reflecting the fluid passage recesses 34-35 (resp. the cavities 37-38).

[0054] More generally, a passageway 59a (resp. A portion 53a) is formed in a radially inner portion of the blade 13 so as to fluidly connect the upper cavity 34 (resp. Of the upper cavity 37) and the through inner cavity 35 (resp. the through inner cavity 38).

[0055] Figure 4 shows a blade section 13 of the radially more outward than the section of Figure 3 (see Figure 1). As illustrated in Figure 4, radially outer portion of the blade 47b a passage is provided in the inner wall 47 so as to connect

fluidly cavity pressure face 33 to upper surface of the cavity 34. Thus, the cavity of the intrados 33 and extrados cavity 34 are fluidly connected in series, as shown by arrow translating the passage of fluid between said cavities. More generally, 47b a passage is provided in a radially outer portion of the blade 13 so as to fluidly connect the cavity pressure face 33 and the suction recess 34.

[0056] In view of the foregoing, to the pressure side cavity 33, the cavity 34 and the suction through inner cavity 35 are fluidly connected in series, in that order.

[0057] Figure 5 illustrates a section of the blade 13 radially more outward than the section of Figure 4 (see Figure 1). As can be seen in Figure 5, a bottom wall 64 closes the radially outer end of the cavity pressure face 33 of the suction cavity 34, the through inner cavity 35 of the second cavity of supply 39 and the downstream cavity 40. Furthermore, a bottom wall 66 closes the radially outer end of the through inner cavity 38. in contrast, the upstream cavity 31, the first supply cavity 32, the cavity of intrados 36 of the suction cavity 37 and the cavity extrados 41 radially extend beyond the bottom walls 64, 66.

[0058] Figure 6 illustrates a blade section 13 of the radially more outward than the section of Figure 5 (see Figure 1). As can be seen in Figure 6, a passage 68 fluidly connects the cavity pressure face 36 to the suction cavity 37 without passing through the through inner cavity 38 through the bottom wall 66. Thus, the cavity intrados 36 and extrados cavity 37 are fluidly connected in series, as shown by arrow translating the passage of fluid between said cavities. In this case, the passage 68 overhangs the through inner cavity 38. More generally, a passage 68 is formed in a radially outer portion of the blade 13 so as to fluidly connect the cavity pressure face 36 and the suction cavity 37 .

[0059] In view of the foregoing, to the pressure side cavity 36, the cavity 37 and the suction through inner cavity 38 are fluidly connected in series, in that order.

[0060] Furthermore, the suction cavity 41 may serve as auxiliary convex side cavity for feeding a cooling cavity 42 of the bath, positioned below the tub in a radial direction. The positioning of the auxiliary suction cavity 41 of the side of the extrados, away from the leading edge and the trailing edge, preferably in an intermediate position between the leading edge 20 and trailing edge 22, can limit heating of the cooling air as it flows into the cavity of auxiliary suction 41 and supplied to the cooling cavity 42 of the tub as cold as possible fluid, for efficient cooling of the head 14. due to the bottom wall 64,

[0061] Figure 7 shows diagrammatically, from the section of Figure 3, the flow of cooling air in the embodiment previously described. The cavities fluidly connected in series between them have been shown with densities of identical points. The arrows indicate a possible flow direction of the fluid, this direction being determined in accordance with the following.

[0062] In the present embodiment, air inlet sections may be provided in the blade root 12 for cooling air in the cavities of feed. For example, an air inlet section may be provided to at least one or each of the following cavities: the first supply cavity 32, the cavity pressure face 33, the cavity pressure face 36, the second feed cavity 39, the cavity 41 of auxiliary suction.

[0063] The direction of circulation of the cooling fluid obtained in these conditions is shown in Figure 8. As is apparent from Figure 8, the coolant flows of the foot 12 towards the head 14 in the supply cavities 32, 39, in the cavities of lower surface 33, 36, the internal through-cavities 35, 38 and into the downstream cavity 40, and head 14 to the foot 12 in the cavities 34 and 37 suction.

[0064] When the rotor on which the blade 10 is mounted rotates in the direction S shown in Figure 8, the cooling air is further subjected to the Coriolis force. Given the flow direction described above, in the supply cavities 32, 39, in the cavities of lower surface 33, 36, the internal through-cavities 35, 38 and into the downstream cavity 40, the air is pressed against the lower surface of said cavities side, which is shown in solid lines in Figure 8. however, in the upper cavities 34, 37, the air is pressed against the upper side of said cavities.

[0065] Thanks to this cooling and arrangement of the through walls and inner walls, the thermomechanical stresses accumulated in the blade 13 during operation are largely reduced. In fact, Figure 8 also illustrates, schematically, the deformations undergone by the structure of the blade 13. As is apparent from Figure 8, the walls of intrados and extrados 16, 18 deform more that the walls internal 43, 45, 47, due to their higher operating temperature. The presence of through internal cavities such that the cavities 35, 38 - and to some extent the second supply cavity 39, which also meets the definition of a through inner cavity within the meaning of the present disclosure - permits to

[0066] In addition, the presence and relatively small deformation of the inner walls 43, 45, 47 are used to properly support the bottom walls 64, 66 which extend transversely. Indeed, being at a lower temperature to the pressure side and suction sides 16, 18, the inner walls 43, 45, 47 present, all things being equal, better mechanical properties, are stiffer and better withstand the stresses resulting from the centrifugal force associated with the rotation of the turbine. This recovery efforts by the inner walls 43, 45, 47 also relieves the walls of pressure and suction 16, 18, which consequently saw their increased lifespan.

[0067] Figure 9 is substantially identical to Figure 3 except that the section of the blade 13 in question (plane IX-IX in Figure 1) is selected to show the presence of orifices allowing the airflow within the blade 13 and outwardly of the blade 13.

[0068] An orifice 62, preferably a plurality of holes, is formed in the through wall 51, between the first supply cavity 32 and the upstream cavity 31. The opening 62 provides power to the upstream cavity 31 in air indirectly cooling, as discussed above.

[0069] An orifice 69, preferably a plurality of holes, is formed in the through wall 63, between the second supply cavity 39 and the downstream cavity 40. The hole 69 allows to feed the downstream cavity 40 in air indirectly cooling, as discussed above.

[0070] Furthermore, discharge ports such as ports 31c, 35c, 38c, 40c are provided in the pressure side wall 16, opening out respectively on the upstream cavity 31, the internal through-cavities 35, 38 and the cavity 40. the downstream discharge ports 31c, 35c, 38c, 40c can be configured to create a protective fluid film on the outer surface of the blade 13, downstream of said orifices. To this end, the holes 31c, 35c, 38c, 40c can be oriented towards the trailing edge 22. In this case, said orifices create protective films of respectively 32 ', 33', 36 'and 40' respectively protecting cavities 32, 33, 36, 40.

[0071] Similarly, the discharge ports 31d may be provided in the wall of upper 18 in particular at the leading edge. In this case, the discharge ports 31d to connect the upstream cavity 31 to the outside of the blade 13 and allow the creation of a protective fluid film 37 to protect the suction cavity 37.

[0072] As is apparent from Figure 9, the cavities and the discharge ports are provided so that a circuit protects itself. For example, the air entering through the cavity pressure face 36 flows to the suction cavity 37 and then through inner cavity 38, and then is discharged through the discharge port 38c where it contributes to the film sheath fluid 36 'that protects the cavity pressure face 36. It is advantageous to do so, the air flows generally against the flow in the cavities, that is to say, the trailing edge towards the leading edge. This is the case in this example, since the air outlet cavity, namely through inner cavity 38 is located upstream of the air inlet cavity, i.e. the cavity pressure face 36.

[0073] The blade 10 may be manufactured according to the method known per se foundry lost wax. To this end, the cores are first manufactured, which rings occupy the space to be formed to the cavities during the production of the mold.

[0074] The cores corresponding to the cavities 33-35 on the one hand, 36-38 on the other hand can be prepared by any suitable method, for example by molding with occasional use of inserts in the mold, or by additive fabrication.

[0075] The maintenance of the cores during manufacture of the mold can be made in a manner known to those skilled in the art. The kernels

33-35 corresponding to cavities on the one hand, 36-38 on the other hand, can be supported by two supports situated in the foot 12. In order to avoid an excessive number of supports and simplify the arrangement of the foot 12, it is possible to provide a foot per ring, retention completed by an appendage delocalized. This projection is preferably provided to form, in the final blade, an opening which is capable of being subsequently recapped by a brazed ball.

[0076] After casting metal and destruction of cores, cavities may undergo dust removal operation. To do this, it is possible to provide the blade in a dust hole, for example by blade head. Where appropriate, for the dedusting of through cavities 35, 38 respectively closed off by the bottom walls 64, 66, the shape of the cooling cavity 42 of the tub and / or the passage 68 may be adapted to allow the passage of a rod integral with the core and the completion of the dust collection hole directly by casting, and / or to allow implementation of the hole by machining after casting of the blade. The dust hole may possibly also allow evacuation of debris during operation.

[0077] Figures 10 to 12 show a turbine blade in other embodiments. In these figures, elements corresponding or identical to those of the first embodiment receive the same sign reference to the hundreds digit by, and will not be described again.

[0078] Figures 10 to 12 are diagrammatic views similar to that of Figure 7 and are depicted according to the same convention described above.

[0079] In the blade 113 according to a second embodiment shown in Figure 10, the cavity 137 is used as auxiliary suction cavity. The cavity 141 is used as a suction cavity fluidly connected in series between the pressure side cavity 136 and through inner cavity 138. The bottom wall 66 described with respect to Figure 5 may be extended to seal the cavity intrados 136 and the suction cavity 141, given the fact that it is not necessary in this embodiment to arrange a similar passage in the passage 68 described in connection with Figure 6.

[0080] Thus, in this embodiment, the blade comprises a first internal cooling circuit having the cavity pressure face 133, the cavity 134 and the suction through inner cavity 135, and a second internal cooling circuit comprising the cavity pressure face 136, the cavity 141 and the suction through inner cavity 138. for the purposes of this disclosure, the first and second internal cooling circuits of this embodiment are identical. Moreover, the cavities 131, 132, 139, 140 of the cooling circuit leading edge and trailing edge are unchanged.

[0081] This embodiment makes it possible to provide a cooling cavity of the largest bath as the cooling cavity 42 described above and allows a similar manufacturing the nuclei of internal cooling circuits.

[0082] In the blade 213 according to a third embodiment shown in FIG 11, the first internal cooling circuit formed by the cavities 236-238 is identical to the first internal cooling circuit according to the first embodiment (cavities 36- 38). However, the cavity 234 is used as auxiliary upper cavity. The cavity 241 is used as a suction cavity fluidly connected in series between the pressure side cavity 233 and through inner cavity 235. Therefore, in order to provide between the cavity pressure face 233 and the cavity 241 of suction passage which does not pass through the through inner cavity 235 (a similar passage the passage 68 described in connection with Figure 6), it is necessary, compared to the first embodiment,

[0083] Thus, in this embodiment, the blade comprises a first internal cooling circuit having the cavity pressure face 233, the cavity 241 and the suction through inner cavity 235 and a second internal cooling circuit having the cavity pressure face 236, the cavity 237 and the suction through inner cavity 238. for the purposes of this disclosure, the first and second internal cooling circuits of this embodiment are identical. In addition, the first inner wall 245 of the first internal cooling circuit is merged with the second inner wall of the second internal cooling circuit.

[0084] This embodiment makes it possible to merge the air from the auxiliary suction inlet cavity section 234 with the air inlet section of the second supply cavity 239, thereby facilitating the arrangement of the blade root and its production.

[0085] A blade 313 according to a fourth embodiment, shown in Figure 12, is similar to the blade 213 according to the third embodiment, except that it comprises a first internal cooling circuit formed in this case by the cavities 336, 337 and 338. This embodiment may be advantageously implemented for smaller blades than those described previously. To further reduce the size of the blade 313, it would be possible to unify the one hand the upstream cavity 331 with the first supply cavity 332, and / or on the other hand the downstream cavity 340 with the second cavity of supply 339. While the previous embodiments have internal walls and therethrough configured to form a triple structure in H,

Such a structure described and regarding the other embodiments mutatis mutandis transpose.

[0086] The blade 10 according to any of the embodiments described may be a turbine moving blade of a turbine engine 100, as shown schematically in Figure 13.

[0087] Although the present invention has been described with reference to specific embodiments, modifications may be made to these examples without departing from the general scope of the invention as defined by the claims. For example, although the flow of fluid into the cavities has been described according to a certain direction corresponding to a preferred embodiment, it will be apparent to those skilled in the art that it is possible to change the radial position of the passages between cavities and / or otherwise dispose the air inlet sections of the blade root so as to impose a direction of cooling fluid flow different from that described in the present disclosure.

[0088] Further, although the cavities have been shown smooth and empty, it is possible to provide for flow disturbers are to increase the heat exchange.

[0089] In general, individual features of the different embodiments shown / mentioned can be combined in additional embodiments. Therefore, the description and drawings should be considered illustrative rather than restrictive sense.

CLAIMS

1. blade (10) for a turbine comprising a blade root (12) defining a radially inner end of the vane and a blade (13, 113, 213) radially extending outwardly from the foot vane (12) and having a pressure side wall (16) and a wall suction (18) connected to the pressure side wall (16) at a leading edge (20) and a trailing edge (22 ) of the blade, the blade (13, 113, 213) comprising at least a first internal cooling circuit comprising at least one cavity pressure face (33, 36) radially extending along the pressure side wall (16 ) and a first inner wall (47, 45) arranged between the pressure side wall (16) and the wall suction (18), at least one cavity suction (34, 37) radially extending along the wall ofextrados (18) and a second inner wall (47, 43) arranged between the pressure side wall (16) and the wall suction (18), characterized in that the first cooling system further comprises at least one through inner cavity (35, 38) defined between two through walls (59, 57, 55, 53) each extending between the pressure side wall (16) and the wall suction (18), the through inner cavity (35, 38) radially extending along the pressure side wall (16) and the suction wall (18), wherein the cavity pressure face (33, 36), the suction cavity ( 34, 37) and through inner cavity (35, 38) are fluidly connected in series.characterized in that the first cooling circuit further comprises at least one through inner cavity (35, 38) defined therethrough between two walls (59, 57, 55, 53) each extending between the pressure side wall (16) and the suction wall (18), the through inner cavity (35, 38) radially extending along the pressure side wall (16) and the suction wall (18), wherein the cavity intrados (33, 36), the suction cavity (34, 37) and through inner cavity (35, 38) are fluidly connected in series.characterized in that the first cooling circuit further comprises at least one through inner cavity (35, 38) defined therethrough between two walls (59, 57, 55, 53) each extending between the pressure side wall (16) and the suction wall (18), the through inner cavity (35, 38) radially extending along the pressure side wall (16) and the suction wall (18), wherein the cavity intrados (33, 36), the suction cavity (34, 37) and through inner cavity (35, 38) are fluidly connected in series.the through inner cavity (35, 38) radially extending along the pressure side wall (16) and the suction wall (18), wherein the cavity pressure face (33, 36), the cavity extrados (34, 37) and through inner cavity (35, 38) are fluidly connected in series.the through inner cavity (35, 38) radially extending along the pressure side wall (16) and the suction wall (18), wherein the cavity pressure face (33, 36), the cavity extrados (34, 37) and through inner cavity (35, 38) are fluidly connected in series.

2. A blade according to claim 1, wherein the cavity pressure face (33, 36), the suction cavity (34, 37) and through inner cavity (35, 38) are fluidly connected in series in this order.

3. A blade according to claim 1 or 2, wherein the first inner wall (45) is connected to a first of said walls through-

(55, 57) and the second inner wall (43, 47) is connected to a second (53, 59) of said through walls.

4. A blade according to any one of claims 1 to 3, comprising a third through-wall (53, 55, 57, 59, 61) connected to the first inner wall (45) or second inner wall (43, 47) , the internal cooling circuit having a second through cavity (38, 35, 39) radially extending along the pressure side wall, the wall suction and third through-wall (53, 55, 57, 59, 61).

5. A blade according to any one of claims 1 to 4, wherein the cavity pressure face (36, 233, 236) and the suction cavity (37, 241, 237) are formed on either side of the through inner cavity (38, 235, 238) and a passage (68) fluidly connects the cavity pressure face (37, 241, 237) to the suction cavity (37, 241, 237) without passing through the internal cavity traversing (38, 235, 238).

6. A blade according to claim 5, wherein the cavity pressure face (36, 233, 236) is provided at the trailing edge (22) and the suction cavity (37, 241, 237) at the edge drive (20) with respect to the through inner cavity (38, 235, 238).

7. A blade according to any one of claims 1 to 6, wherein the first inner wall (47, 45) and the second inner wall (47, 43) are each bounded by two through walls (61, 59, 57, 55 , 53, 51), each through-wall (61, 59, 57, 55, 53, 51) extending between the pressure side wall (16) and the wall suction (18).

8. A blade according to any one of claims 1 to 7, wherein the pressure side wall (16) has at least one opening (35c, 38c) connecting the through inner cavity (35, 38) outside of the blade (13).

9. A blade according to any one of claims 1 to 8, the blade (13) comprising a second internal cooling circuit (236, 237, 238) identical to the internal cooling circuit (233, 241, 235), in particular wherein the first inner wall (245) of the first internal cooling circuit is merged with the second inner wall of the second internal cooling circuit.

10. A blade according to any one of claims 1 to 9, comprising a at its radially outer end bathtub (14), and wherein the first internal cooling circuit comprises an auxiliary suction cavity (41, 137, 234) s radially extending along the suction wall (18) and configured to supply a cooling cavity (42) of the tub.

11. The turbomachine (100) comprising a blade according to any one of claims 1 to 10.