Non-axisymmetric crankcase treatment with controlled opening

Abstract

Non-axisymmetric card treatment with controlled opening. Turbomachine compressor housing (200) comprising openings (201) machined into the thickness of the housing from an inner face (2001) of the housing and arranged side by side on a circumference of the housing, characterized in that it also comprises a movable ring (220), formed by at least two annular portions, located on an outer face (2002) of the housing opposite the openings and capable of moving along the circumference of the housing so as to open and close the openings in the housing to activate or deactivate a housing treatment, the movable ring comprising the same number of slots (202) as openings in the housing. Figure for the abstract: Fig. 2A

Description

Title of the invention: Non-axisymmetric crankcase treatment with controlled opening technical field

[0001] The present invention relates to the general field of turbo-machine compressors, and more particularly to the treatment of the housing of turbo-machine compressors. Previous technique

[0002] Turbomachine compressors consist of blades driven in rotation inside a casing which ensures the sealing of the air stream with the outside of the engine.

[0003] It is known that the play existing between the ends of the moving blades of the compressor and the casing forming the internal wall of the air flow duct degrades the efficiency of the turbomachine engine.

[0004] Furthermore, this play can alter and degrade the compressor's operation to the point of triggering a surge phenomenon resulting from the separation of the airflow from the blade surface. Controlling the airflow at the blade tips is crucial for achieving both good aerodynamic efficiency of the compressor and a sufficient margin against the surge phenomenon.

[0005] To limit the impact of this parasitic flow between the blade tips and the casing, the internal surface of the casing can be treated locally by creating cavities within its thickness opposite the blades. Documents FR 2 989 742, GB 2 408 546 and US 2016 / 153465 provide examples of casing treatment.

[0006] However, the pumping phenomenon only occurs when the compressor is heavily loaded, that is, when it is operating in the upper part of its operating range. Outside this zone, crankcase treatments are therefore no longer useful and may even lead to a loss of compressor efficiency.

[0007] It is therefore desirable to have a compressor housing in which the slots in the housing treatment can be closed or opened to avoid the pumping phenomenon while maintaining good compressor efficiency. Description of the invention

[0008] The invention relates to a turbomachine compressor housing comprising openings cut into the thickness of the housing from an inner face of the housing and arranged side by side on a circumference of the housing, characterized in that it also comprises a movable ring, formed by at least two annular portions, present on an outer face of the housing opposite the openings and adapted to move along the circumference of the housing so as to close and open the openings in the housing to activate or deactivate a housing treatment, the movable ring comprising the same number of slots as openings in the housing.

[0009] When the openings in the casing are aligned with the slots in the moving ring, that is, when the openings in the casing are opposite the slots in the moving ring, the openings on the casing form the slots of a non-axisymmetric casing treatment, because they are located along the circumference of the casing and open onto the groove. In other words, they form axial slots arranged in an azimuthal direction and are therefore non-axisymmetric with respect to the compressor's axis of rotation, whereas axisymmetric casing treatments consist of circumferential grooves and are symmetric with respect to the compressor's axis of rotation.

[0010] Thanks to the invention, the slots in the crankcase treatment can be opened or closed by means of the movable ring. This allows for active crankcase treatment when operating conditions require it, for example during takeoff, to prevent the pumping phenomenon, and inactive crankcase treatment when the compressor is no longer under load, for example during cruise, to maximize compressor efficiency. Thus, the invention makes it possible to control the opening of the crankcase treatment.

[0011] According to a particular feature of the invention, each opening of the housing has a width greater than or equal to the width of the associated slot of the movable ring, and each opening of the housing has a length greater than or equal to the length of the associated slot of the movable ring.

[0012] According to another particular feature of the invention, the housing also includes at least one spring assembling the movable ring to the housing configured so that the openings of the housing are open when the spring is at rest.

[0013] The spring allows the movable ring to return to an initial position or to a safety position, in which its slots are opposite the openings in the housing, so that the slots in the housing treatment are completely open for the housing treatment to be active.

[0014] According to another particular feature of the invention, the housing includes an electric motor comprising a camshaft, the cam being configured to move the movable ring along the circumference of the housing so as to open or close the openings of the housing.

[0015] The camshaft allows the movable ring to move along the circumference of the housing, and more particularly the cam allows the movable ring to move by an amplitude at least equal to the width of an opening in the housing so as to fully open or close the openings in the housing, and therefore so as to open or close completely the slots of the crankcase treatment.

[0016] According to another particular feature of the invention, the housing includes an actuator configured to move the movable ring along the circumference of the housing so as to open or close the openings of the housing.

[0017] The actuator can play the same role as the camshaft, and thus allows the movable ring to be moved along the circumference of the housing in order to open or close the slots in the housing treatment. In this way, it allows the movable ring to be moved by an amplitude at least equal to the width of an opening in the housing.

[0018] According to another particular feature of the invention, the dimensions of the slots in the movable ring and the openings in the housing are equal.

[0019] This means that the slots in the movable ring and the openings in the housing have the same length and width. This makes it easier to open and close the slots in the housing treatment, because by moving the movable ring the width of a housing opening, the corresponding slot in the housing treatment can be fully opened or closed.

[0020] According to another particular feature of the invention, the number of openings in the casing is between 40 and 850.

[0021] According to another particular feature of the invention, the movable ring and the housing are made of the same material. Brief description of the drawings

[0022] Other features and advantages of the present invention will become apparent from the description given below, with reference to the attached drawings which illustrate examples of embodiment without any limiting character.

[0023] [Fig-1] [Fig.1] represents, schematically and partially, a crankcase of turbomachine presser according to an embodiment of the invention.

[0024] [Fig.2A] The [Fig.2A] represents, schematically and partially, the closed slots of the compressor housing treatment of the [Fig.1].

[0025] [Fig.2B] The [Fig.2B] represents, schematically and partially, the open slots of the compressor housing treatment of the [Fig.1].

[0026] [Fig. 3] [Fig. 3] schematically and partially represents a turbomachine compressor housing according to another embodiment of the invention. Description of embodiments

[0027] Fig. 1 represents, schematically and partially, a turbomachine compressor housing 100 according to a first embodiment of the invention.

[0028] The housing 100 includes openings cut (or shaped) in the thickness of the housing from the inner face 1001 of the housing 100. The openings are arranged next to each other on the circumference of the housing 100.

[0029] The housing 100 also includes a movable ring 120 located on the outer face 1002 of the housing 100. The movable ring 120 has the same number of slots as the openings in the housing 100 and can move along the circumference of the housing 100 so as to open or close the openings in the housing 100 by means of its own slots. By aligning the slots of the movable ring 120 with the openings in the housing 100—that is, when the slots of the movable ring 120 are opposite the openings in the housing 100—a housing treatment is formed in which the slots are open when the openings in the housing 100 are open.

[0030] Each opening in the housing 100 has a width greater than or equal to the width of the associated slot in the movable ring 120 (or the slot opposite said opening), and each opening in the housing 100 has a length greater than or equal to the length of the associated slot in the movable ring 120 (or the slot opposite said opening). This ensures that the openings in the housing 100 are fully open when the housing treatment is to be activated.

[0031] In addition, the distance between each opening of the housing 100 is greater than or equal to the width of the associated slot of the movable ring 120. This ensures that the openings of the housing 100 are completely closed when the housing treatment is to be deactivated.

[0032] The movable ring 120 is formed of two annular portions 121 and 122. In this first embodiment, the two annular portions 121 and 122 are assembled together by a pointed screw 130, but they can, instead, be assembled by any other means of assembly, for example a system composed of a centering pin and a screw and nut assembly for holding in position.

[0033] Having a movable ring 120 formed of at least two annular portions 121 and 122 makes it easier to mount the movable ring 120 on the housing 100.

[0034] The housing 100 includes a piston 140 fixed at one end to the movable ring 120 and at the other end to the housing 100 by means of a guide pin 125. The piston 140 controls the movement of the movable ring 120 along the circumference of the housing 100, allowing it to be moved by an amplitude at least equal to the width of the openings in the housing 100 to fully open and / or close the openings in the housing 100 and thus the slots in the housing treatment. The guide pin 125 stiffens the housing 100 and provides a fixed point for attaching the piston 140.

[0035] To move the movable ring 120 on the housing 100, the piston 140 can be replaced by an actuator.

[0036] Figures 2A and 2B show a cross-sectional view of the openings 201 open ([Fig. 2B]) or closed ([Fig. 2A]) of the housing 200 of [Fig. 1] thanks to the movement of the movable ring 220 and its slots 202. As indicated with reference to [Fig. 1], the openings 201 of the housing 200 are cut (or shaped) into the thickness of the housing. 200 from its inner face 2001 and are arranged side by side on the circumference of the housing 200. The movable ring 220 has the same number of slots 202 as openings 201 in the housing 200 and is positioned on the outer face 2002 of the housing 200 so that it can open or close the openings 201 in the housing 200 by moving along the circumference of the housing 200. In this embodiment, the slots 202 of the movable ring 220 have the same width and length as the openings 201 in the housing 200. Furthermore, the distance between the openings 201 in the housing 200 is identical to the distance between the slots 202 of the movable ring 220. Thus, when the slots 202 of the movable ring 220 coincide with the openings 201 of the housing 200, the openings 201 of the housing 200 are completely open ([Fig.2B]) and the slots of the housing treatment are open.When the slots 202 of the movable ring 220 cover the openings 201 of the housing 200, the openings 201 of the housing 200 are completely closed and the slots of the housing treatment are closed ([Fig. 2A]). The housing treatment 200 is therefore inactive in the case of [Fig. 2A] (slots of the housing treatment closed) and it is active in the case of [Fig. 2B] (slots of the housing treatment open).

[0037] Fig. 3 represents, schematically and partially, a compressor housing 300 of a turbomachine 310 according to a second embodiment of the invention.

[0038] As indicated with reference to [Fig.1], the housing 300 includes openings cut or shaped in the thickness of the housing 300 from the inner face 3001 of the housing 300. The openings are arranged next to each other along the circumference of the housing 300.

[0039] The housing 300 also includes a movable ring 320 located on the outer face 3002 of the housing 300. The movable ring 320 has the same number of slots as the openings in the housing 300 and can move along the circumference of the housing 300 so as to open or close the openings in the housing 300 by means of its own slots to open or close the slots in the housing. As indicated with reference to [Fig. 1], each opening in the housing 300 has a width greater than or equal to the width of the associated slot in the movable ring 320, and each opening in the housing 300 has a length greater than or equal to the length of the associated slot in the movable ring 320. Furthermore, the distance between each opening in the housing 300 is greater than or equal to the width of the associated slot in the movable ring 320.

[0040] The movable ring 320 is formed of two annular portions 321 and 322. As previously stated, the two annular portions 321 and 322 can be assembled together by a pointed screw or by any other means of assembly.

[0041] In order to move the movable ring 320 and close or open the slots in the housing treatment and thus the openings in the housing 300, the housing 300 includes an electric motor 330 comprising a camshaft 332. By pivoting, the cam 332 allows The movable ring 320 is moved along the circumference of the housing 300. The cam 332 can bear against a projecting portion 326 on one of the annular portions 322 to pivot and move the movable ring 320. The electric motor 330 and the camshaft 332 allow the movable ring 320 to be moved by an amplitude at least equal to the width of an opening in the housing 300. A pin 327 may be present to lock the projecting portion 326 during the movement of the movable ring 320.

[0042] The housing 300 may also include a spring 340 attached to the movable ring 320 and to the housing 300 by means of a pin 325. This spring 340 is configured so that, at rest, the openings in the housing 300 are open, i.e., so that the slots in the movable ring 320 do not obstruct the openings in the housing 300 (as in [Fig. 2B]) in order for the housing treatment to be active. As before, the pin 325 also serves to stiffen the housing 300 in addition to providing a fixed point for attaching the spring 340.

[0043] Regardless of the embodiment, the openings in the housing can all be identical.

[0044] Regardless of the embodiment, the slots in the movable ring can all be identical. Advantageously, the slots in the movable ring and the openings in the housing have the same dimensions, i.e., they have the same length and width; and the distance between the openings in the housing is equal to the distance between the corresponding slots in the movable ring. This allows the slots in the movable ring to coincide with the openings in the housing, and the movable ring only needs to be moved by the amplitude of its slots to fully open or close the openings in the housing and thus the slots in the housing treatment.

[0045] Regardless of the embodiment, the housing can be a single piece.

[0046] Regardless of the embodiment, the number of openings in the housing (and therefore in the moving ring) is between 40 and 850, for example between 45 and 810, or between 60 and 210. This is because the housing treatment requires between 3 and 8 slots per rotor blade, and a rotor comprises between 15 and 90 blades. This range of values ​​therefore covers all possibilities.

[0047] Regardless of the embodiment, the housing and the movable ring can be made of the same material. This allows both parts to be subjected to the same thermal and mechanical stresses and therefore ensures that opening or closing the housing treatment will always be possible, even in the event of thermal expansion.

[0048] Alternatively, the housing and the moving ring can be made of different materials, but it is necessary that these two materials have similar or even identical physical properties so that their thermal expansion is similar.

[0049] The expression "between ... and ..." should be understood as including the terminals.

Claims

Demands

1. A turbomachine compressor (310) housing (100, 200, 300) comprising openings (201) cut into the thickness of the housing from an inner face (1001, 2001, 3001) of the housing and arranged side by side on a circumference of the housing, characterized in that it also comprises a movable ring (120, 220, 320), formed by at least two annular portions (121, 122, 321, 322), present on an outer face (1002, 2002, 3002) of the housing opposite the openings and capable of moving along the circumference of the housing so as to open and close the openings of the housing to activate or deactivate a housing treatment, the movable ring comprising the same number of slots (202) as openings in the housing.

2. Compressor housing (100, 200, 300) according to claim 1, wherein each opening (201) of the housing has a width greater than or equal to the width of the associated slot (202) of the movable ring (120, 220, 320), and each opening of the housing has a length greater than or equal to the length of the associated slot of the movable ring.

3. Compressor housing (300) according to any one of claims 1 or 2, also comprising at least one spring (340) assembling the movable ring (320) to the housing configured so that the openings in the housing are open when the spring is at rest.

4. Compressor housing (300) according to any one of claims 1 to 3, comprising an electric motor (330) including a camshaft (332), the cam (332) being configured to move the movable ring along the circumference of the housing so as to open or close the openings of the housing.

5. Compressor housing according to any one of claims 1 to 3, comprising an actuator configured to move the movable ring along the circumference of the housing so as to open or close the openings of the housing.

6. Compressor housing according to any one of claims 1 to 5, wherein the dimensions of the slots in the moving ring and the openings in the housing are equal.

7. Compressor housing according to any one of claims 1 to 6, wherein the number of openings in the housing is between 40 and 850.

8. Compressor housing according to any one of claims 1 to 7, wherein the moving ring and the housing are made in the same material.

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