BE1024699B1 - LOW MEMORY PRESSURE COMPRESSOR FOR AXIAL TURBOMACHINE - Google Patents

Abstract

The invention relates to a low-pressure compressor (4) for a turbojet engine. The compressor (4) comprising: an axis of rotation (14); an annular vein about the axis of rotation (14) which is adapted to guide an annular flow (18) passing through the compressor and which has a wall for guiding the annular flow (18) in a first direction. The guide wall is made of a shape memory material so that said guide wall is adapted to change shape to deflect the annular flow in a second direction inclined relative to the first direction. The wall is a rotor blade (24) or stator (26), or an inner shell (30) or an outer casing (28), its material is metal or composite organic matrix.

Description

(30) Priority data:

(73) Holder (s):

SAFRAN AERO BOOSTERS S.A. 4041, HERSTAL (MILMORT) Belgium (72) Inventor (s):

VALLINO Frédéric 4100 SERAING Belgium (54) LOW PRESSURE COMPRESSOR WITH SHAPE MEMORY FOR AXIAL TURBOMACHINE (57) The invention relates to a low pressure compressor (4) of turbofan engine. The compressor (4) comprising: an axis of rotation (14); an annular vein around the axis of rotation (14) which is capable of guiding an annular flow (18) passing through the compressor and which comprises a wall for guiding the annular flow (18) in a first direction. The guide wall is made of a shape memory material so that said guide wall is able to change shape in order to deflect the annular flow in a second direction inclined relative to the first direction. The wall is a rotor (24) or stator (26) blade, or an internal ferrule (30) or an external casing (28), its material is metallic or composite with organic matrix.

FIG. 3

BELGIAN INVENTION PATENT

FPS Economy, SMEs, Middle Classes & Energy

Publication number: 1024699 Deposit number: BE2016 / 5807

Intellectual Property Office International Classification: F01D 5/14 F01D 9/04 F01D 17/16 F01D 17/14 F01D 5/28 B29C 70/88 B29D 99/00 Date of issue: 01/06/2018

The Minister of the Economy,

Having regard to the Paris Convention of March 20, 1883 for the Protection of Industrial Property;

Considering the law of March 28, 1984 on patents for invention, article 22, for patent applications introduced before September 22, 2014;

Given Title 1 “Patents for invention” of Book XI of the Code of Economic Law, article XI.24, for patent applications introduced from September 22, 2014;

Having regard to the Royal Decree of 2 December 1986 relating to the request, the issue and the maintenance in force of invention patents, article 28;

Considering the patent application received by the Intellectual Property Office on 26/10/2016.

Whereas for patent applications falling within the scope of Title 1, Book XI of the Code of Economic Law (hereinafter CDE), in accordance with article XI. 19, §4, paragraph 2, of the CDE, if the patent application has been the subject of a search report mentioning a lack of unity of invention within the meaning of the §ler of article XI.19 cited above and in the event that the applicant does not limit or file a divisional application in accordance with the results of the search report, the granted patent will be limited to the claims for which the search report has been drawn up.

Stopped :

First article. - It is issued to

SAFRAN AERO BOOSTERS S.A., Route de Liers 121, 4041 HERSTAL (MILMORT) Belgium;

represented by

LECOMTE Didier, P.O. Box 1623, 1016, LUXEMBOURG;

a 20-year Belgian invention patent, subject to payment of the annual fees referred to in article XI.48, §1 of the Code of Economic Law, for: LOW PRESSURE MEMORY COMPRESSOR

SHAFT FOR AXIAL TURBOMACHINE.

INVENTOR (S):

VALLINO Frédéric, Rue de la Vecquée 430, 4100, SERAING;

PRIORITY (S):

DIVISION:

divided from the basic application: filing date of the basic application:

Article 2. - This patent is granted without prior examination of the patentability of the invention, without guarantee of the merit of the invention or of the accuracy of the description thereof and at the risk and peril of the applicant (s) ( s).

Brussels, 01/06/2018, By special delegation:

BE2016 / 5807

Description

LOW PRESSURE MEMORY COMPRESSOR FOR

AXIAL TURBOMACHINE

Technical area

The invention relates to the stability of a compressor. More specifically, the invention relates to the field of turbomachine compressors. The invention also relates to an axial turbomachine, in particular an aircraft turbojet or an aircraft turboprop.

Prior art

The operation of a turbojet compressor exposes it to the pumping phenomenon which limits its maximum performance. In order to avoid the destructive consequences, a safety margin is defined to guarantee the integrity of the compressor at the expense of its maximum potential. In addition, it is known to a person skilled in the art of leakage devices making it possible to reduce the necessary safety margin, and thereby to optimize operating safety and the maximum exploitable performance.

Document EP 2 305 960 A1 discloses a low pressure turbofan double-flow compressor. The compressor includes a rotor surrounded by the outer wall of the outer casing. This wall has an orifice closed by a leakage insert that opens when the pressure inside the compressor exceeds a threshold value. This insert has a shape memory membrane. However, the gain offered by this solution remains limited.

Summary of the invention

Technical problem

The object of the invention is to solve at least one of the problems posed by the prior art. More specifically, the invention aims to optimize the performance and operating safety of a low pressure compressor. The invention also aims to provide a simple solution,

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BE2016 / 5807 resistant, light, economical, reliable, easy to produce, convenient to maintain, easy to inspect, and improving performance.

Technical solution

The subject of the invention is a low pressure turbojet compressor, the 5 compressor comprising: an axis of rotation; an annular vein which is capable of guiding an annular flow passing through the compressor and which comprises a wall for guiding the annular flow in a first direction; remarkable in that the guide wall is made of a shape memory material, so that said guide wall is capable of changing shape in order to divert the annular flow in a second direction inclined with respect to the first direction.

According to particular embodiments, the compressor can include one or more of the following characteristics, taken individually or according to all possible technical combinations:

- The wall is a stator vane or a rotor vane of the low pressure compressor which includes an upstream part and a downstream part.

The wall is curved, the change in shape of the wall modifying the wall curvature.

The change in shape of the shape memory material modifies the inclination of the upstream part relative to the downstream part.

The change in shape of the shape memory material modifies the inclination of the upstream part and / or the downstream part with respect to the axis of rotation.

The change in shape of the shape memory material changes the spatial orientation of the stator vane or the rotor vane.

The compressor includes a circular support in which the stator or rotor vane is embedded.

Depending on its thickness, the stator vane or the rotor vane comprises a lower half with a first material and a lower half with a second material, the first or second material being shape memory.

The wall is an internal ferrule or an external casing.

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The change in shape of the inner shroud or the outer casing results in a change in diameter of the inner shroud or the outer casing respectively.

The first direction and the second direction are inclined with respect to each other at least: 3 °, or 5 °, or 8 °, or 12 ° at the axial level of the wall.

The first direction and the second direction are each inclined relative to the axis of rotation by an angle greater than or equal to: 5 °, or 10 °, or 15 °, or 20 °, or 25 °, or 30 ° at axially level of the wall.

The wall changes in shape in response to a wall temperature change.

The shape of the wall is changed in response to the application of a difference of electrical potentials to the wall.

The change in shape deforms the wall radially and / or axially.

The wall comprises a metallic material, in particular with a change in martensitic-austenitic phase during its change in shape.

The wall comprises a composite material with a matrix and a fibrous reinforcement; the fibrous reinforcement being with shape memory, and / or the matrix comprises particles of a shape memory material.

The wall comprises a monobloc and / or material portion, said portion being able to change shape in order to deflect the annular flow in the second direction.

The stator vane or the rotor vane is full and / or monobloc, and / or made of material.

The stator vanes are connected to the internal ferrule and / or to the external casing.

The wall, and / or the composite, and / or the matrix comprises a deformation memory polymer.

The invention also relates to a turbomachine comprising a low pressure compressor, remarkable in that the low pressure compressor conforms to the invention, preferably the low pressure compressor comprises a first upper curve of stability as a function of

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BE2016 / 5807 4 the pressure and the flow which it provides when the wall guides the annular flow in a first direction; and a second upper stability curve as a function of the pressure and the flow rate that it provides when the wall deflects the annular flow in the second direction.

According to an advantageous embodiment of the invention, the turbomachine further comprises a high pressure compressor arranged downstream of the low pressure compressor, and / or a blower arranged upstream of the low pressure compressor.

In general, the advantageous modes of each object of the invention are also applicable to the other objects of the invention. As far as possible, each object of the invention can be combined with the other objects. The objects of the invention can also be combined with the embodiments of the description, which in addition can be combined with one another.

Benefits

The invention makes it possible to modify the geometry of the fluid stream, and therefore to modify the flow which dictates the operating mode of the compressor.

Thus, the maximum flow rate of the compressor is increased, and the stall point is pushed back. The possibilities offered by the compressor are improving, while maintaining sufficient operational safety.

The mapping of the operating curves can be adjusted to provide a wider operating range. In the case of a graph representing pressure as a function of flow, the stability curves can deviate from one another. They can translate along one or each axis of the graph.

Brief description of the drawings

FIG. 1 represents an axial turbomachine according to the invention.

FIG. 2 is a diagram of a turbomachine compressor according to the invention.

FIG. 3 illustrates a portion of the compressor according to the invention.

Figure 4 shows a shape memory vane according to a first embodiment of the invention.

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BE2016 / 5807 5

FIG. 5 shows a shape memory vane according to a second embodiment of the invention.

Description of the embodiments

In the following description, the terms internal and external refer to a positioning relative to the axis of rotation of an axial 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 in reference to the main flow direction of the flow entering and passing through the turbomachine.

îo Figure 1 shows a simplified axial turbomachine. In this specific case, it is a double-flow turbojet engine. The turbojet engine 2 comprises a first level of compression, called a low-pressure compressor 4, a second level of compression, called a high-pressure compressor 6, a combustion chamber 8 and one or more levels of turbines 10. In operation, the mechanical power from the turbine 10 transmitted via the central shaft to the rotor 12 sets in motion the two compressors 4 and 6. The latter comprise several rows of rotor blades associated with rows of stator blades. The rotation of the rotor around its axis of rotation 14 thus makes it possible to generate an air flow and to compress it progressively until the inlet of the combustion chamber 8.

An inlet fan commonly designated as a fan or blower 16 is coupled to the rotor 12 and generates an air flow which is divided into a primary flow 18 passing through the various above-mentioned levels of the turbomachine, and into a secondary flow 20 passing through a duct annular (partially shown) along the machine to then join the primary flow at the turbine outlet. Reduction means 15, such as a planetary reduction gear, can reduce the speed of rotation of the blower and / or of the low pressure compressor relative to the associated turbine. The reduction means may include a shape memory material, for example in order to influence the performance of the turbomachine and its safety. The secondary flow can be accelerated so as to generate a thrust reaction useful for the flight of an aircraft.

The primary 18 and secondary 20 flows are coaxial annular flows and

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BE2016 / 5807 fitted one inside the other. They are channeled through the casing of the turbomachine and / or of the ferrules. For this purpose, the casing has cylindrical partitions which can be internal and external.

FIG. 2 is a sectional view of a compressor of an axial turbomachine such as that of FIG. 1. The compressor can be a low pressure compressor 4. One can observe therein a part of the fan 16 and the separation nozzle 22 of the primary flow 18 and secondary flow 20. The rotor 12 comprises several rows of rotor blades 24, in this case three. It shows an internal support in the form of a drum to which the rotor vanes 24 are linked. These blades 24 can form a one-piece assembly with the drum. As a variant or in addition, the rotor 12 may comprise one or more discs which are arranged along the axis of rotation 14 and to which the rotor blades 24 are linked. Again as a variant or in addition, certain rows of rotor blades 24 can be mounted in grooves of the rotor 12 which receive the blades via dovetail type retentions.

The low pressure compressor 4 comprises several rectifiers, in this case four, which each contain a row of stator vanes 26.

The rectifiers are associated with the fan 16 or a row of rotor blades to straighten the air flow, so as to convert the speed of the flow into static pressure and / or dynamic pressure.

The stator vanes 26 extend essentially radially from an outer casing 28, and can be fixed and immobilized therein using through pins. Within a single row, the stator vanes 26 are regularly spaced from one another, and have the same angular orientation in the flow. Advantageously, the blades of the same row are identical. Optionally, the spacing between the blades can vary locally as can their angular orientations. Some vanes may differ from the rest of the vanes in their row. The outer casing 28 can be formed of several rings, or half-shells. It can be formed by a succession of external ferrules connected axially to each other.

In addition, the stator vanes 26 can support internal ferrules 30. These internal ferrules 30 receive circular seals ensuring seals with the rotor 12. In particular, the seals can be layers

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BE2016 / 5807 7 annulars of abradable material which crumble in contact with wipers formed around the rotor 12.

In order to control the risk of stalling and pumping in the compressor 4, the latter is made locally from shape memory material. For example, its rotor 12 and its stator comprise one or more shape memory materials. The change in shape can result from a change in temperature, but also from a power supply, the application of a magnetic field, and / or mechanical stress.

FIG. 3 is a portion of compressor 4, for example a portion of the low pressure compressor 4 of FIG. 2.

The vanes (24; 26), the external casing 28 and the internal ferrule 30 form walls guiding the primary flow 18 which passes axially through the compressor 4. These walls guide the flow in a first direction, and in a second direction following the change shape of the shape memory material (s).

The compressor 4 is shown in solid lines in a first configuration, and in dotted lines in a second configuration allowing the primary flow 18 to be guided in another direction. The change of direction followed by the primary flow 18 can be greater than 1 °, this change can be observed locally; for example in an annular boundary layer; and or in a passage between two blades in the same row.

The outer casing 28 can be made of shape memory material. Optionally, the inclination of its wall relative to the axis of rotation 14 can change. Its change in shape makes it possible to modify the diameter of the external casing 28, for example over its entire length or over a given section. The external casing 28 optionally performs a homothety, for example radially. For example, the section in question may be around a row of blades (24; 26). This tends to modify the direction of flow of the primary flow 18, possibly due to a more marked taper or fading when the shape changes. The change in shape may tend towards, or move away from, the casing 28 of a tubular shape.

A shape memory material as used in the present invention may be a polymeric material, such as polynorbornene,

BE2016 / 5807 transpolyisoprene, an ethylene vinyl acetate copolymer, a methyl acrylate-stearyl acrylate copolymer, an oligo ε caprolactone, αω dimethacrylate; a colyurethane, in particular copolyurethane polyamide; a styrene transpolybutadiene block copolymer, an aliphatic and aromatic oxadiazole block copolymer. Other polymers are possible.

The shape memory material can also be a composite material, in particular with an organic matrix. The composite can also have a fibrous reinforcement filled by the matrix. According to the invention, the matrix as well as the reinforcement can be shape memory. For example, the fibrous reinforcement may comprise fibers of shape memory alloy, these fibers being able to be associated with carbon fibers and glass fibers. The fibers can be arranged in stacked fibrous plies, for example between eight and twenty-five stacked fibrous plies, possibly between twelve and sixteen stacked fibrous plies. The stack can form a fibrous preform. As a variant or in addition, the fibrous folds are arranged in a three-dimensional woven preform.

Furthermore, the matrix may include shape memory particles, and / or be made using one of the previously mentioned shape memory polymers. The shape memory particles can be in the form of fibers, petals, grains; possibly oriented; and / or arranged according to their direction of shape change.

A shape memory material can be a shape memory alloy (AMF). Shape memory alloys are alloys with the capacity to keep an initial shape in memory, to return to it even after a deformation. This cycle can be performed several thousand times. The possibility of alternating between two previously memorized shapes responds to a temperature variation around a critical temperature, and a super elastic behavior allowing elongations without permanent deformation greater than those of other metals, for example up to 10%. Among the main shape memory alloys, there is a variety of nickel and titanium alloys as main constituents, in almost equal proportions, such as nitinol. Other shape memory alloys are possible including: brass, a copper-aluminum alloy, a

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BE2016 / 5807 9 iron-platinum alloy, an indium-cadmium alloy, an iron-nickel alloy, a nickel-aluminum alloy, or stainless steel.

The internal ferrule 30 can also be made of shape memory material. It can be made of shape memory composite. It can in particular comprise a shape memory matrix, and shape memory fibers. These fibers can be fibers of lengths less than: 10mm, or 5mm, or 2mm. The change in shape of the internal ferrule 30 tends to modify the diameter thereof around the axis of rotation 14, possibly according to a homothety. The change can possibly be made over the entire length. The change in shape can also modify its axial length.

The changes in shape of the casing 28 and of the shell 30 tend to modify the passage section of the vein. This section can increase and facilitate the circulation of the primary flow; which reduces the risk of pumping.

In addition, the rotor 24 and stator 26 blades can also change shapes. They can extend radially and / or axially. Consequently, their leading edges 32 and their trailing edges 34 can lengthen and move axially. Their curvatures can tighten or worsen. These deformations influence the compression of the flow 18, and its guidance. The leading edges 32 and the trailing edges 34 of two axially spaced vanes (24; 26) can move away or approach axially. The drum 12 can also deform. According to an option of the invention, at least one or more of the elements among: the rotor 12, the casing 28, the ferrule, the stator vanes 26 and the rotor vanes 24 are free of shape memory behavior; while being at a wall having a shape memory property.

Although the present teaching has been presented in relation to the low pressure compressor, it is also possible to apply it to the high pressure compressor and the blower. An application in the low pressure turbine and in the high pressure turbine is also possible.

Figure 4 sketches a profile of a compressor vane, such as a stator vane. The stator dawn may correspond to those described in relation to FIGS. 2 and 3. This teaching can also be applied to a

BE2016 / 5807 rotor vane, such as those shown in Figures 2 and 3. The axis of rotation 14 is shown as a spatial reference.

The profile of the blade 26 has a curved shape. Its lower surface 36 is concave, and the upper surface 38 is convex. These surfaces (36; 38) extend from the leading edge 32 to the trailing edge 34. Depending on its thickness, the blade 26 has a lower surface layer such as a lower half 40; and an upper layer such as an upper half 42. At least one layer, respectively at least one half (40; 42) comprises a shape memory material; the other layer, respectively the other half, being free of shape memory behavior. These materials can correspond to those described above. Optionally, the two materials are shape memory.

The change in shape can cause a change in the camber of the profile of the blade 26. In the deformed state following the change in shape of the shape memory material, the lower surface 36 can be curved more and the upper surface 38 can still arch. Therefore, the recovery of the primary flow 18 that the blade 26 provides is more pronounced. In the event that it is fixed in the middle of its cord, the trailing edge 34 approaches the leading edge 32, further digging the blade; in addition to shortening it axially. The leading edge 32 and the trailing edge 34 move around the circumference. They approach the dawn of the row which is opposite the lower surface 36. They can close the passage with the neighboring dawn. Consequently, the setting angle of the blade changes, which is particularly beneficial in the context of a high speed compressor, that is to say one whose rotation speed is greater than: 10,000 rpm. min, or 15,000 rpm, or 18,000 rpm. Performance can improve.

According to the invention, it is also conceivable that the deformation of the shape memory material produces the opposite deformation to that which has been described above. Thus, the dawn can lengthen axially, its straightening can decrease, its upper surface and its lower surface can be tender, that is to say that they flatten out. Pumping can be avoided since the flow velocity is preserved.

According to the invention, the present profile may correspond to a profile in the middle radially of the blade, while one or each profile linked to a support remains

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BE2016 / 5807 identical. From then on, the dawn bends locally. The bending can be gradual.

Figure 5 sketches a compressor blade profile according to a second embodiment of the invention. The axis of rotation 114 is drawn as a guide.

The second embodiment of the invention is substantially identical to the first embodiment, it however differs therefrom by the anchoring and / or by the direction of the general deformation shown. The anchor can be at the trailing edge 134 which remains in place, while the leading edge 132 moves according to the circumference. It approaches a blade of the annular row to which the present blade 126 belongs, and approaches another of these blades. Dawn 126 intercepts primary flow 118 less, and idles less. This modification can facilitate the flow, and possibly avoid pumping.

Alternatively, the blade is held from its leading edge, and its trailing edge is movable.

According to the invention, the present profile may correspond to a profile in the middle radially of the blade, while one or each profile linked to a support remains identical. From then on, the dawn twists locally. The twist can be progressive.

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Claims (20)

Claims 1. Low pressure compressor (4) of a turbojet engine, the low pressure compressor (4) comprising: - an axis of rotation (14; 114); 2. Low pressure compressor (4) according to claim 1, characterized in that the wall is a stator vane (26; 126) or a rotor vane (24) 3. Low pressure compressor ( 4) according to claim 2, characterized in that the wall is curved, the change in shape of the wall modifying the wall curvature. 4. Low pressure compressor (4) according to one of claims 2 to 3, characterized in that the change in shape of the shape memory material modifies the inclination of the upstream part relative to the downstream part. 5 characterized in that the change in shape deforms the wall radially and / or axially. 5 stator (26; 126) or the rotor vane (24) is rigidly linked. 5. Low pressure compressor (4) according to one of claims 2 to 4, characterized in that the change in shape of the memory material of 25 shape changes the inclination of the upstream part and / or the downstream part with respect to the axis of rotation (14; 114). 5 - an annular stream which is capable of guiding an annular flow (18; 118) passing through the low pressure compressor (4) and which comprises a wall for guiding the annular flow (18; 118) in a first direction; characterized in that the guide wall is made of a shape memory material, so that said guide wall is able to change shape in order to deflect the annular flow (18; 118) in a second inclined direction compared to the first direction. 6. Low pressure compressor (4) according to one of claims 2 to 5, characterized in that the change in shape of the memory material of 2016/5807 BE2016 / 5807 13 shape changes the orientation in space of the stator vane (26; 126) or the rotor vane (24). 7. Low pressure compressor (4) according to one of claims 2 to 6, characterized in that it comprises a circular support to which the blade 8. Low pressure compressor (4) according to one of claims 2 to 7, characterized in that, depending on its thickness, the stator vane (26) or the rotor vane (24) comprises a lower surface half (40) with a first material and one upper surface half (42) with a second material, the first or second material being in shape memory. 9. Low pressure compressor (4) according to claim 1, characterized in that the wall is an internal ferrule (30) or an external casing (28). 10. Low pressure compressor (4) according to claim 9, characterized in that the change in shape of the internal shell (30) or of the external casing 11. Low pressure compressor (4) according to one of claims 1 to 10, characterized in that the first direction and the second direction are inclined relative to each other by at least: 3 °, or 5 °, or 8 °, or 12 ° to 20 axially level of the wall. 12. Low pressure compressor (4) according to one of claims 1 to 11, characterized in that the first direction and the second direction are each inclined relative to the axis of rotation (14; 114) by a greater angle or equal to: 5 °, or 10 °, or 15 °, or 20 °, or 25 °, or 30 ° at level 25 axially from the wall. 13. Low pressure compressor (4) according to one of claims 1 to 12, characterized in that the change in shape of the wall takes place in response to a change in temperature of the wall. 2016/5807 BE2016 / 5807 14 14. Low pressure compressor (4) according to one of claims 1 to 13, characterized in that the change in shape of the wall is effected in response to the application of a difference in electrical potentials to the wall. 15 form. 15. Low pressure compressor (4) according to one of claims 1 to 14, 15 (28) causes a change in diameter of the internal ferrule (30) or the external casing (28) respectively. 15 of the low pressure compressor (4) which comprises an upstream part and a downstream part. 16. Low pressure compressor (4) according to one of claims 1 to 15, characterized in that the wall comprises a metallic material, in particular with a change in martensitic-austenitic phase during its change of shape. 17. Low pressure compressor (4) according to one of claims 1 to 16, characterized in that the wall comprises a composite material with a matrix and a fibrous reinforcement; the fibrous reinforcement being with shape memory, and / or the matrix comprises particles of a memory material of 18. Low pressure compressor (4) according to one of claims 1 to 17, characterized in that the wall comprises a monobloc portion and / or made of material, said portion being capable of changing shape in order to deflect the annular flow ( 18; 118) in the second direction. 20 19. Turbomachine (2) comprising a low pressure compressor (4), characterized in that the low pressure compressor (4) conforms to one of claims 1 to 18, preferably the low pressure compressor (4) comprises a first curve superior stability as a function of the pressure and flow it provides when the wall guides the flow 25 annular (18; 118) in a first direction; and a second upper stability curve as a function of the pressure and the flow rate it provides when the wall deflects the annular flow (18; 118) in the second direction. 2016/5807 BE2016 / 5807 15 20. Turbomachine (2) according to claim 19, characterized in that it further comprises a high pressure compressor (6) disposed downstream of the low pressure compressor (4), and / or a blower (16) disposed upstream of the low pressure compressor (4). BE2016 / 5807 BE2016 / 5807