BE1030042B1 - MOBILE WHEEL WITH INTERMEDIATE RING - Google Patents

Abstract

Method of manufacturing a turbine engine impeller (38) comprising: making a groove or a notch on each blade (40) of an annular row of blades (40), at an intermediate radial position of the vanes (40); the positioning of an intermediate ring (42) comprising housings in which the grooves or notches engage; and fixing, preferably by welding, the intermediate ring (42) to the blades (40). The invention also relates to a mobile wheel (38) obtained by this process and a turbomachine provided with such a wheel (38).

Description

Description

MOBILE WHEEL WITH INTERMEDIATE RING

Domain

The invention relates to the manufacture of a moving wheel for a multi-flow turbomachine.

Prior art

Multi-flow turbomachines have the characteristic of using different annular air flows, coaxial with each other, each of the flows meeting or not meeting various components of the turbomachine (compressor, combustion chamber, turbine, stator blades, etc. ).

Thus, it is known to use a moving compressor wheel which is common to two adjacent flows separated by a wall. As such, the impeller includes an intermediate ring that keeps the two flows sealed from each other.

To assemble this intermediate ring, supports are provided on each of the blades and angular sections of the ring are riveted to each of the supports.

On the one hand, such an assembly is complex. It requires significant assembly time and requires the use of specific tools.

On the other hand, such a moving impeller is only suitable for a design where two flows are already separated from each other upstream of the impeller. The geometry of the intermediate ring is not suitable for a zone of the turbomachine where a single flow upstream of the wheel is split into several flows downstream of the wheel, because the geometry known from the state of the art would generate in such a situation significant aerodynamic losses and therefore lower engine performance.

Such flow separation zones are found in particular at the level of a separation nozzle downstream of a fan or downstream of a compressor of the turbomachine.

Summary of the Invention

Technical problem

The invention aims to solve the drawbacks identified in the state of the art. In particular, the invention aims to propose a wheel design and its method of manufacture, which allow easier manufacture and which make the wheel suitable for occupying a zone of the turbomachine where an air flow is split without affecting the efficiency. of the turbomachine.

Technical solution

The invention relates to a method of manufacturing a turbine engine impeller comprising: the production of a groove or a notch on each blade of an annular row of blades, at an intermediate radial position of the blades; the positioning of an intermediate ring comprising housings in which the grooves or notches engage, the intermediate ring comprising a leading edge, a trailing edge, an internal radial surface for guiding the flow and a radial surface outer flow guiding surface, said surfaces extending from the leading edge to the trailing edge; and fixing, preferably by welding, of the intermediate ring to the blades.

The groove or notch provided on each vane allows the ring to be pre-held during its fixing. They thus make assembly easier and potentially more precise. The shape of the groove or the notch can be such that the position of the intermediate ring is positioned so as to pre-guide the flow in a direction advantageous for its separation.

Indeed, the intermediate ring subdivides the flow which is located upstream of the wheel and pre-guides it towards the two (or more) flows which are located downstream of the wheel. It thus improves the efficiency of the turbomachine. It thus subdivides the inter-blade space into two channels in which the particles of the upstream flow engage towards

One or the other of the downstream flows. The ring is "intermediate" in the sense that it is neither placed at the roots nor at the heads of the blades, but at a radially intermediate position between the roots and the heads of the blades. When an upstream stream is split into more than two downstream streams, several respective intermediate rings can be provided.

According to an advantageous embodiment of the invention, the intermediate ring is formed of several ring sections and the step of positioning the ring includes positioning all the ring sections. The sections allow easier handling and therefore simplified assembly. They also allow the simultaneous installation of several parts of the ring by different operators.

According to an advantageous embodiment of the invention, the fixing step is at least partially carried out before all of the sections have been put into position. This overlapping of the two steps saves manufacturing time. It is understood that alternatively, the ring sections are all positioned before the fixing step (for example by welding) begins.

According to an advantageous embodiment of the invention, the positioning of the ring comprises the radial fitting of ring sections on the blades. The camber of the blades and the curvature of the ring sections (which together form a ring) play a keying role when inserting the ring sections radially around the blades, offering a further efficiency gain when the making.

According to an advantageous embodiment of the invention, the positioning of the ring comprises the simultaneous axial and circumferential sliding of ring sections. Thus, ring sections can be brought parallel to the propeller described by the blades. For example, two hoops, one or both of which include notches corresponding to the profile of the blades, can be brought from upstream and from downstream, in particular simultaneously, then fixed to each other.

According to another alternative, the intermediate ring is in one piece and it is put into position by simultaneously axial and circumferential sliding.

According to an advantageous embodiment of the invention, the method further comprises a step of positioning an outer ring and a step of fixing, preferably by welding, the outer ring to the outer radial ends of the blades. This ring makes it possible to avoid intrados/extrados leakage vortices and to better control contact with the abradable.

According to an advantageous embodiment of the invention, the method further comprises positioning and fixing, preferably by welding, auxiliary vanes extending radially internally and/or externally from the intermediate ring, and/or extending radially inward from the outer ring. These auxiliary vanes make it possible to act independently on one of the two downstream flows, thus optimizing the efficiency of the turbomachine by compressing or accelerating one of the flows more than the other. Auxiliary vanes can be moved into position and attached before or after the rings (or sections of rings) are/have been attached to the vanes. According to an advantageous mode of the invention, the auxiliary vanes have a radial height of at least 15% of the height of the vanes.

According to an advantageous embodiment of the invention, the intermediate ring and/or the outer ring is/are essentially formed of composite material, and is/are optionally fitted with metal inserts intended to be welded to the vanes. This weight gain for a rotating element further improves efficiency.

Alternatively, all the elements of the moving wheel are metallic.

According to an advantageous mode of the invention, the blades are encircled by the intermediate ring. Thus, the ring is axially longer than the blades and it encapsulates them.

According to an advantageous embodiment of the invention, the intermediate ring and/or the outer ring has (have) irregularities on its (their) radially outer surface(s) and/or on its (their) surface(s). s) radially internal, the irregularities being in particular of the three-dimensional contouring type. These irregularities are bumps and/or hollows, the height or depth of which are of a very low order of magnitude compared to the dimensions of the ring. These irregularities further improve the guiding of the flow and therefore the efficiency of the turbomachine.

The invention also relates to a turbine engine moving wheel obtained by a manufacturing process in accordance with one of the embodiments described above.

The groove, the notch and the fixing, in particular by a weld bead, are observable on the mobile wheel once manufactured and distinguishes it from a mobile wheel obtained by a different process. The same goes for ring sections.

Micrographs of the wheel or of sections of it make it possible, if necessary, to distinguish it from another wheel.

The invention also relates to a turbomachine comprising: a splitter nozzle splitting an inlet air flow into a primary annular flow and a secondary annular flow; and a moving wheel comprising an annular row of rotor blades and arranged upstream of the separation nozzle; the turbomachine being remarkable in that the movable wheel comprises an intermediate ring with a trailing edge, the trailing edge of the intermediate ring being arranged at a radial position close to that of the separating nose.

The annular row of rotor blades can be arranged directly upstream of the separation nozzle. A row of stator vanes can alternately separate them. 5 By "adjacent" is meant a difference of less than 10% between the radial position of the separating nose and the radial position of the trailing edge of the intermediate ring.

The separation spout can have a circular edge forming an upstream end, rounded or not. From the circular edge extends an external surface, for internal guiding of the secondary flow, and an internal surface, for external guiding of the primary flow.

The flow is thus pre-guided by the intermediate ring before being split into two flows. This pre-guiding reduces the risks of turbulence or separation of the flow and allows an improvement in the efficiency of the turbomachine.

According to an advantageous embodiment of the invention, the impeller constitutes the first row of rotor blades of a low-pressure compressor. At this point, the mobile wheel allows the creation of a secondary flow which can bypass the combustion chamber and can participate in the thrust, thus increasing the efficiency of the engine.

The invention also relates to a turbomachine comprising: a splitter nozzle splitting an inlet air flow into a primary annular flow and a secondary annular flow; and a moving wheel comprising an annular row of rotor blades and arranged directly upstream of the separation nozzle; the turbomachine being remarkable in that the moving wheel is obtained by one of the manufacturing processes mentioned above.

According to an advantageous embodiment of the invention, in the vicinity of the separation nozzle, the primary flow and the secondary flow flow along two respective main directions of flow, respectively defining a primary angle and a secondary angle, with respect to the axis of rotation of the wheel, and the trailing edge of the intermediate ring guides the inflow according to a trailing angle which is between the primary angle and the secondary angle. A compromise is thus found to limit losses when the two flows downstream of the nozzle are very divergent.

This orientation of the intermediate ring also offers flexibility for the design of the veins downstream of the wheel, in particular allowing a steep swan neck at the outlet of a compressor, and therefore a high compression ratio and better efficiency.

According to an advantageous embodiment of the invention, the transverse profile of the ring has a camber and/or an inflection point. Alternatively, the profile can be straight, presenting a constant angle from the entry angle at the leading edge to the exit angle at the trailing edge. Depending on the geometry of the primary and secondary flow veins, one or the other design is more or less advantageous. In particular, a camber makes it possible to conduct a greater volume of air towards one or the other of the downstream flows.

According to an advantageous embodiment of the invention, the wheel comprises a plurality of rings, at least two of which differ in their profiles, their radial position, their circumferential length, their thickness, their shape and/or their assembly method.

Advantages of the invention

The invention is particularly advantageous in that it makes it possible to propose a moving wheel adapted to a zone of the turbomachine where a flow is split into two flows (or more) while limiting the effects on the efficiency of the engine and offering a less complex manufacturing than the known wheels.

An additional advantage of the presence of an intermediate ring is the protection of the downstream veins in the event of ingestion of foreign objects into the engine.

The pre-guiding of the flows also allows greater freedom in the trajectory of the downstream veins and in particular a more abrupt gooseneck, because the flow which enters the gooseneck can be pre-guided and present less risk of detachment .

Then, the secondary flow (respectively primary) can be “energized”, i.e. accelerated and/or compressed more than the primary flow (resp. secondary).

Description of the drawings

Figure 1 is a sectional view of a turbomachine;

Figure 2 illustrates the separation of a stream;

FIG. 3 represents an isometric view of a mobile wheel according to the invention;

Figures 4A to 4C show examples of blades;

Figures SA and 5B illustrate examples of ring sections;

Figures GA and GB represent examples of hoops and rings;

Figure 7 is an isometric view of a mobile wheel according to the invention;

Figures 8A and 8B represent an isometric view of a mobile wheel according to the invention.

Description of an embodiment

In the following description, the terms “internal” and “external” refer to positioning relative to the axis of rotation of a turbomachine. The axial direction corresponds to the direction along the axis of rotation of the turbomachine. The radial direction is perpendicular to the axis of rotation. Upstream and downstream are to be considered with reference to the flow direction of a flow in the turbomachine.

The figures show the elements schematically and are not drawn to scale. In particular, certain dimensions are enlarged to facilitate reading of the figures.

Figure 1 shows a schematic sectional view of a turbomachine 1. An inner casing 2 guides a primary flow F1 which successively passes through compressors 4 (low and high pressure), a combustion chamber 6 and turbines 8 (high and low pressure), before escaping through a nozzle 10. The combustion energy drives the turbines 8 in rotation. The turbines 8 drive the compressors 4, directly by means of transmission shafts, or indirectly by means of reducers.

The turbines 8 also rotate a rotor 12 with fan blades 14 which set in motion a secondary flow F2. Most of the thrust of the turbomachine is generated by the propulsion of the flow F2 by the rotor 12, which is said to be “propulsive”. The primary flow F1 is used as an oxidizer to ensure the rotation of the turbines and the rotor 12.

A fairing 16 and a nacelle 18 delimit a passage 34 which is traversed by the secondary flow F2.

Structural arms 20 take up the forces between the nacelle 18 and the engine casing 2.

An annular row of stator vanes 22 (“outlet guide vanes”, OGV) can be arranged downstream of the rotor 12 to straighten the flow F2.

A reducer 23 can also greatly reduce the speed of rotation (between the turbines 8 and the blades 14).

The turbomachine 1 has a separation nozzle 36 to separate the air flow F into two annular flows.

Figure 2 schematically shows the separation of a flow into two annular flows.

An input stream F is split into a primary stream F1 (and into a secondary stream F2.

The primary F1 and secondary F2 flows respectively flow in an annular vein 32, 34. These flows can correspond to the primary and secondary flows of FIG. 1 or to other flows separated from each other in the turbomachine.

The separation of the flows is carried out by a separation nozzle 36 of circular shape around the axis of the turbomachine X. The separation nozzle 36 may have an upstream circular edge which may be a sharp or rounded edge. It is arranged directly upstream of a surface 34.1 which internally guides the secondary flow

F2 and a surface 32.1 which externally guides the primary flow F1. These two surfaces 32.1, 34.1 can be approximately truncated cones in the vicinity of the spout 36. The flows F1 and F2 have a main direction of flow which is oriented along the angles a4 and a, in the vicinity of the spout 36. The angle ay can be between -60° and +15°. The angle a" can be between -15° and +60°, while naturally being greater than 04.

The separating nose 36 or its circular edge defines a radius R up to the X axis.

Directly upstream of the spout 36 is a rotating assembly in the form of an impeller 38 equipped with an annular row of vanes 40 extending from an internal disc 41. The impeller 38 can be (but not is not necessarily) the rotor 12 of Figure 1 and the vanes 40 may be the blades 14.

The blades 40 are fixed to the internal disk 41 by welding, or the blades 40 are manufactured simultaneously with the disk 41, by machining the same raw material or by additive manufacturing. Any type of welding can be considered (electron beam welding, orbital friction, linear friction, TIG).

Alternatively, the blades 40 can be fixed to the disc 41 by dovetails or by other removable means.

At least one intermediate ring 42 extends circumferentially over 360° encircling disc 41. Ring 42 may be axially confined to the blades as drawn in FIG. 2 or alternatively encircle each blade 40 on the upstream and/or downstream side (see figure 3). Figure 2 highlights the fact that the intermediate ring 42 comprises a leading edge 42.1 and a trailing edge 42.2. The latter is located at a radial height R which may in particular be between 30% and 70% of the radial height of the blades 40. The leading and trailing edges of the intermediate ring are circular around the axis of rotation of wheel 38.

The ring 42 can be metallic or be made of composite material. The ring 42 can be fixed by pins, by screwed elements, or welded to the blades 40. If necessary, the welding of a composite ring is made possible by the integration of metal inserts in the composite ring.

The intermediate ring 42 has an inner radial surface 42.3 and an outer radial surface 42.4, each extending from the leading edge 42.1 to the trailing edge 42.2.

The radial thickness of the ring can vary from upstream to downstream. The surfaces 42.3, 42.4 can be provided with irregularities helping to guide the flow (“contouring”) and thus have local thickness variations.

The profile of the ring 42 can also have a camber and/or a point of inflection. The intermediate ring 42 may have an upstream guide angle at the leading edge which is different from the downstream angle at the trailing edge.

Alternatively, the flow guiding angle can be constant from upstream to downstream.

Figure 2 highlights the vanishing angle a which corresponds to the orientation of the inflow F in the vicinity of the trailing edge 42.2 of the ring 42. The ring 42 is designed so that this angle is between to, and to".

Figure 3 shows an isometric view of impeller 38 with its vanes 40 extending from disc 41, and its intermediate ring 42.

Figures 4A to 4C show different examples of blades 40.

FIG. 4A represents a blade 40 with its leading edge 40.1, its trailing edge 40.2 and its lower surface 40.3. A notch 40.5 is provided to receive the ring 42. In the example shown, the notch 40.5 is arranged on the leading edge but it can be arranged at other places on the blade 40.

Figure 4B shows a variant with a groove 40.6. In this example, the groove 40.6 extends axially over the entire blade 40 as well as on both sides (extrados and intrados). A shorter groove and extending only on one side of the blade 40 is also possible. The groove can be rectilinear, parallel or not to the axis of the turbomachine. It can alternatively be curved and follow the curve of ring 42.

FIG. 4C shows another alternative with a notch on the lower surface 40.3, creating a shoulder at the junction between an outer part of the lower surface 40.31, thinner, and an inner part of the lower surface 40.32, thicker.

The notch or groove allows the fixing of the ring 42 by means of a pin, fasteners, or by means of a point or a weld bead.

In one embodiment, the ring 42 is formed from several ring sections which, when assembled together, form the ring 42. Figure 5A shows a ring section 44. The leading and trailing edge 44.1 44.2 of each section form part of the leading edge 42.1 and trailing edge 42.2 of the ring. Edges 144.3 and 444 are intended to butt to other similar edges of adjacent sections. A bead of weld can be used to secure the ring sections 44 together. The edges 44.3 and 44.4 can be straight, parallel to the X axis or not, or be curved and follow the curvature of an intrados or an extrados.

Top surface 44.5 forms part of outer surface 42.4 of ring 42.

A housing 44.6 is arranged in section 44. This housing has a closed contour of dimension slightly greater than the profile of blade 40, considered in the radial position intended to receive section 44. This section 44 can be fitted around the blade 40 by a substantially radial movement (to within the curvature of blade 40).

The clearance between the housing 44.6 and the blade 40 can be filled by a seal or by a weld bead, in order to provide continuity of material between the blades 40 and the ring 42 once the assembly is assembled.

In an alternative not illustrated, the housing 44.6 is made of two half-housings at each circumferential end (on the edges 44.3 and 44.4) and the section 44 is thus inserted radially into the inter-blade circumferential space.

FIG. 5B shows a section 44 in an alternative embodiment with an emerging housing 44.6. This design makes it possible to insert section 44 around blade 40 by a substantially helical movement (combining axial translation and circumferential rotation) from downstream of blade 40.

Housing 44.6 can open out onto the leading edge of ring 42.

Alternatively, a section 44 (not shown, having an emerging housing and complementary to that of FIG. 5B) can be brought in the same way from upstream.

In another alternative, the ring sections 44 comprise several housings (see dotted lines in FIG. 5B) and each section can thus cover several adjacent blades. The wheel 38 can thus be formed by assembling several angular sectors on the disc 41, each sector comprising several blades and one or more corresponding ring sections 44.

Figure GA shows a variant in which two hoops 46, 48 encapsulate the blades 40 from upstream and downstream, potentially with a helical movement, the two hoops 46, 48 forming two axial sections of the ring 42, and comprising respective housings 46.6, 48.6 cooperating with part of the blades and in particular their notches or grooves. The hoop 46 comprises an upstream edge 46.1 which forms the leading edge 42.1 of the ring and the section 48 comprises a downstream edge 48.2 which forms the trailing edge 42.2 of the ring.

FIG. 6B shows an alternative where ring 42 is formed of a single section 50, one edge 50.1 of which corresponds to the leading edge of ring 42 and one edge 50.2 corresponds to the trailing edge of ring 42. This one-piece ring 42 includes through housings 50.6. This is engaged around blades 40 from downstream. Alternatively, it can be brought in from upstream.

Figure 7 shows an embodiment where an outer ring 52 is added to the outer ends (heads) of the vanes 40. Any means of attachment is possible between the outer ring 52 and the vanes 40, such as welding or using mounting platforms.

The outer ring 52 may have irregularities (“contouring”) on the inner surface 52.3 and/or on its outer surface 52.4.

FIGS. 8A and 8B show an embodiment where auxiliary vanes 54 are inserted between two vanes 40 circumferentially adjacent.

In Figure 8A, which has no outer ring, auxiliary vanes 54 are carried and attached to ring 42.

In the example of FIG. 8B, the auxiliary vanes 54 are in contact with both the intermediate ring 42 and the outer ring 52. Alternatively, the height of the auxiliary vanes 54 is shorter than the distance between the two rings 42, 52 and the auxiliary vanes 54 are therefore only fixed to one of the two rings 42, 52.

The auxiliary vanes 54 can have a height of at least 15% and in particular around a quarter of the height of the vanes 40. Alternatively, the auxiliary vanes 54 can cover the entire distance between the ring 42 and the disc 41, or the entire height between the ring 42 and the head of the vanes 40, or even the entire radial distance between the intermediate ring 42 and the outer ring 52. As for their axial dimension, the auxiliary vanes 54 can extend between 50 and 100 % of the axial length of the blades 40.

In the example illustrated, the auxiliary vanes 54 are “one” in number per inter-vane space and extend radially outwards from the ring 42. It is understood that the number of auxiliary vanes carried by the ring 42 and their orientations (exterior and/or interior) can be chosen according to the compression or the speed to be printed independently to the primary or secondary streams. For example, one auxiliary vane 54 may be pointing inward, and two auxiliary vanes 54 may be pointing outward, with the inner vane being circumferentially located midway between the outer vanes.

The invention relates not only to the wheel 38 and the turbomachine 1 but also to the method of manufacturing the wheel 38. This essentially comprises the positioning and fixing of the intermediate ring or ring sections to the blades, in particular the housings of the ring cooperating with a groove or a notch of the blade.

The disk 41 and the vanes 40 can be in one piece, made in one piece, or the vanes 40 can be attached to the disk 41 and fixed on the latter. The various steps for fixing the ring 42 or its sections 44 can be carried out before the blades 40 are fixed to the disc, or after. Alternatively, the assembly can be hybrid, with some blades being in one piece with the disc and others being added to it. Also, the attachment of the ring or its sections to the blades can be done simultaneously with the attachment of other blades to the disc. According to another variant, the ring sections 44 can be fixed to the vanes 40 (possibly by angular sector of several vanes), then the vanes and their ring sections can be fixed to the disc 41.

Similarly, the realization of the notches and grooves in the blades can be made after the fixing of the blades to the disc or before. Alternatively, notches and grooves can be made on some vanes while other vanes are being attached or while certain ring sections are being attached to certain vanes.

In the same way, the auxiliary vanes 54 can be fixed to the intermediate ring or its sections, and/or to the external ring, before these rings are fixed to the vanes, or afterwards.

A person skilled in the art will understand that the invention can be applied to any rotor which precedes a nozzle for separating a stream, regardless of the nozzle in question.

Each technical characteristic of each illustrated example is applicable to the other examples. In particular, the number of blades, the number of rings or ring sections, their arrangement, their transverse profile, their length, their camber, their shape, etc., can be taken from an embodiment and be applied to another.

The different types of ring section attachment can be combined on the same wheel. Thus, certain segments of the same ring can be brought axially while others are brought radially around the blades. Also,

in the variants with several rings, the same blade can have several notches and/or grooves of different types to engage each of the rings.

Claims (15)

Claims 1. Method of manufacturing a moving wheel (38) of a turbomachine compressor (1) comprising: - producing a groove (40.31, 40.6) or a notch (40.5) on each blade (40) of an annular row of vanes (40), at an intermediate radial position of the vanes (40); - the positioning of an intermediate ring (42) comprising housings (44.6, 46.6, 48.6, 50.6) in which the grooves engage (40.31, 40.6) or notches (40.5), the intermediate ring (42) comprising a leading edge (42.1), a trailing edge (42.2), an internal radial surface flow guiding surface (42.3) and an outer radial flow guiding surface (42.4), said surfaces (42.3, 42.4) extending from the leading edge (42.1) to the trailing edge (42.2); and - fixing, preferably by welding, of the intermediate Vanneau (42) to the blades (40). 2. Method according to claim 1, characterized in that the intermediate ring (42) is formed of several ring sections (44) and the step of positioning the ring (42) comprises positioning of all ring sections (44). 3. Method according to claim 2, characterized in that the positioning of the ring (42) comprises the radial fitting of ring sections (44) on the blades (40). 4. Method according to one of claims 2 or 3, characterized in that the positioning of the ring (42) comprises the simultaneous axial and circumferential sliding of ring sections (44). 5. Method according to claim 1, characterized in that the intermediate ring (42) is Monobloc and it is put into position by simultaneously axial and circumferential sliding. 6. Method according to one of claims 1 to 5, characterized in that it further comprises a step of positioning an outer ring (52) and a step of fixing, preferably by welding, the ring (52) to the outer radial ends of the blades (40). 7. Method according to one of claims 1 to 6, characterized in that it further comprises positioning and fixing, preferably by welding, auxiliary vanes (54) extending radially internally and / or externally from the intermediate ring (42), and/or extending radially inward from the outer ring (52). 8. Method according to the preceding claim, characterized in that the auxiliary vanes (54) have a radial height of at least 15% of the height of the vanes (40). 9. Method according to one of the preceding claims, characterized in that the intermediate ring (42) and / or the outer ring (52) is / are essentially formed (s) of composite material, and is / are optionally provided (s) metal inserts intended to be welded to the blades (40). 10. Method according to one of the preceding claims, characterized in that the vanes (40) are encircled by the intermediate ring (42). 11. Method according to one of the preceding claims, characterized in that the intermediate ring (42) and / or the outer ring (52) has (have) irregularities on its (their) surface (s) radially outer ( s) (42.4, 52.4) and/or on its (their) radially inner surface(s) (42.3, 52.3), the irregularities being in particular of the three-dimensional contouring type. 12. Movable wheel (38) of the turbomachine (1) obtained by a manufacturing process according to one of the preceding claims. 13. Turbomachine (1), comprising: - a splitter nozzle (36) splitting an inlet air flow (F) into a primary annular flow (F1) and a secondary annular flow (F2); and - a moving wheel (38) comprising an annular row of rotor blades (40) and arranged upstream of the separation nozzle (36); the turbomachine (1) being characterized in that the movable wheel (38) comprises an intermediate ring (42) with a trailing edge (42.2), the trailing edge (42.2) of the intermediate ring (42) being arranged at a radial position (R) close to that of the separating nose (36). 14. Turbomachine (1) according to the preceding claim, characterized in that the impeller (38) constitutes the first row of rotor blades (40) of a low-pressure compressor (4). 15. Turbomachine (1), comprising: - a splitter nozzle (36) splitting an inlet air flow (F) into a primary annular flow (F1) and a secondary annular flow (F2); and - a moving wheel (38) comprising an annular row of rotor blades (40) and arranged directly upstream of the separation nozzle (36); the turbomachine (1) being characterized in that the movable wheel (38) conforms to claim 12.