Treatment of the non-axisymmetric shell, including the pressurization chamber, using controlled opening.

Abstract

A housing (100) of a turbine engine compressor (300) includes an inner annular wall (110) and an outer annular wall (120) defining an annular cavity (130) therebetween. The inner annular wall of the housing includes a plurality of grooves (115) formed in the thickness of the inner annular wall, the grooves being circumferentially oriented (D). C ) are arranged adjacent to each other, and each is along the axial direction (D) A The housing also includes a sliding ring (140) present in an annular cavity (130) within the housing. The sliding ring is axially (D) between an open position and a closed position. A The sliding ring (140) moves on the wall of the housing. In the open position, the groove (115) in the inner annular wall (110) of the housing opens into the annular cavity (130). In the closed position, the sliding ring (140) covers at least some of the groove (115).

Description

Technical Field

[0001] This disclosure relates to the general field of turbine engine compressors, and more specifically to the treatment of the compressor housing of a turbine engine. Background Technology

[0002] The compressor of a turbocharged engine consists of rotating blades housed within a casing that isolates the airflow from the external environment surrounding the engine.

[0003] It is known that the gap between the tip of the blades of a mobile compressor and the housing that forms the inner wall of the airflow reduces the efficiency of a turbine engine.

[0004] Furthermore, this gap alters and degrades the compressor's operating performance until airflow over the blade surface is interrupted, triggering a phenomenon known as compressor stall. Controlling airflow at the blade tips is a significant challenge in simultaneously achieving good aerodynamic efficiency and sufficient margin against compressor stall.

[0005] To limit the effects of parasitic flow between the blade tips and the housing, the inner surface of the housing can be locally treated by cutting grooves within it, with the grooves corresponding to the blades within the thickness of the housing. The housing treatment considered in this invention is of the "axial groove" type, corresponding to a series of grooves arranged along the periphery (azimuth direction) of the housing. These grooves are located vertically ("above") the compressor impeller. Therefore, this treatment is non-axisymmetric with respect to the compressor's axis of rotation; hence, it is referred to as non-axisymmetric housing treatment or NACT.

[0006] The presence of these grooves will cause localized changes in flow. The purpose is to influence the mechanisms that lead to compressor stall. Effective casing treatment will extend the compressor's operating range by delaying the occurrence of these mechanisms, particularly by reducing aerodynamic blockage at the impeller head.

[0007] Some NACT designs propose adding an annular cavity or "pressure chamber" within the housing, as described in document WO9420759. This is equivalent to adding a cavity above the slots. This cavity extends to the entire perimeter of the housing, connecting the slots together. This cavity is not directly connected to the airflow or to the secondary air circuit. Therefore, airflow must pass through the slots to enter and exit the cavity. Adding a pressure chamber helps enhance NACT's ability to improve stall margin.

[0008] At all operating speeds, the presence of an annular cavity (boost chamber) with NACT is not necessarily advantageous. At some speeds, the slot alone is sufficient to ensure operability. Furthermore, the cavity inherently possesses its own acoustic modes. If these inherent modes are excited, acoustic resonance may occur, leading to compressor stall. Similarly, for some compressors and at some operating speeds, NACT without an annular cavity or partially without an annular cavity may offer higher efficiency than NACT with an annular cavity.

[0009] Therefore, there is a need for a compressor housing with multiple NACT configurations, namely a housing capable of controlling the communication between the slot and the annular cavity. Summary of the Invention

[0010] To this end, the present invention provides a housing for a turbine engine compressor, the housing comprising an inner annular wall and an outer annular wall defining an annular cavity therebetween, the inner annular wall of the housing comprising a plurality of grooves cut out in the thickness of the inner annular wall, the grooves being arranged adjacent to each other in the circumferential direction, and each groove extending in the axial direction.

[0011] The housing is characterized in that it further includes a sliding ring located in an annular cavity of the housing, the sliding ring being movable in an axial direction between an open position and a closed position, wherein in the open position, a groove on the inner annular wall of the housing opens into the annular cavity, and in the closed position, the sliding ring covers at least some of the grooves such that these grooves do not open into the annular cavity, and the housing further includes an actuation device to move the sliding ring between the open position and the closed position.

[0012] Therefore, the housing of the present invention can optimize non-axisymmetric housing treatment according to the compressor's operating range. For operating speeds where this is necessary, the sliding ring is in the open position to obtain additional stall margin, thereby allowing the housing slots to open into the annular cavity or booster chamber. At speeds or operating ranges where the effect of the housing slots alone is sufficient for treatment, the sliding ring is in the closed position, which particularly prevents speed-dependent acoustic modes that may occur in the annular cavity.

[0013] Using a sliding ring in the annular cavity of the housing not only provides an optimized overall solution for the compressor housing, but also limits the increase in the overall mass of the housing and ensures the structural strength of the housing assembly.

[0014] In one specific feature of the invention, the sliding ring is a single piece. In this case, the actuating device includes a pressurized air injection system communicating with one or more injection orifices in the downstream end portion of the annular cavity, and a plurality of springs held in a compressed state between the upstream end portion of the annular cavity and the sliding ring.

[0015] In another specific feature of the invention, the sliding ring is divided into several annular segments that can slide independently in the axial direction within the annular cavity. This allows for selective control of the closure of the housing slots and reduction of the cavity volume at operating speeds where a reduction in air chamber volume is required. In this case, the actuating device includes a pressurized air injection system communicating with at least one injection orifice disposed in the downstream end portion of the annular cavity, the orifice opposite to each annular segment of the sliding ring, and at least one spring held in a compressed state between the upstream end portion of the annular cavity and each annular segment of the sliding ring.

[0016] In another specific feature of the invention, the sliding ring includes cavities on its inner surface opposite the outer surface of the inner annular wall. These cavities are located at defined points on the inner surface of the sliding ring such that, in the closed position, the cavities conform to the groove. The cavities of the sliding ring can be designed in an aerodynamic shape, such as a crescent shape, thereby giving the groove an aerodynamic shape and thus reducing losses.

[0017] In another specific feature of the invention, the opening of the movable ring has the same size as the groove of the housing.

[0018] The present invention also relates to a turbine engine compressor comprising the housing of the present invention. Attached Figure Description

[0019] Other features and advantages of the invention will become apparent from the following description taken in conjunction with the accompanying drawings, which illustrate examples of non-limiting embodiments.

[0020] [ Figure 1 ] Figure 1 This is a partial schematic diagram of a turbine engine compressor having a housing equipped with a sliding ring according to an embodiment of the present invention, wherein the sliding ring is in the open position.

[0021] [ Figure 2 ] Figure 2 This is a partial schematic diagram of a turbine engine compressor having a housing equipped with a sliding ring according to an embodiment of the present invention, wherein the sliding ring is in the closed position.

[0022] [ Figure 3 ] Figure 3 yes Figure 1 A perspective view of the compressor in the image;

[0023] [ Figure 4 ] Figure 4 yes Figure 2 A perspective view of the compressor in the image;

[0024] Figure 5 yes Figures 1 to 4 A three-dimensional schematic diagram of the sliding ring in the compressor housing.

[0025] Figure 6 yes Figure 5 A detailed partial view of the sliding ring. Detailed Implementation

[0026] Figures 1 to 4 A turbocharger compressor 300 according to one embodiment of the present invention is shown schematically in partial form. The compressor 300 includes a rotor 200 equipped with a plurality of blades 210, the blades 210 being surrounded by a housing 100.

[0027] The housing 100 includes an inner annular wall 110 and an outer annular wall 120, both of which are along the circumferential direction D. C Extending longitudinally, along the axial direction D A The width extends horizontally and along the radial direction D R It has a certain thickness. The inner annular wall 110 and the outer annular wall 120 define an annular cavity 130 therebetween, which forms a pressurization chamber.

[0028] The inner annular wall 110 includes a plurality of slots 115 cut out (or cut) in the wall thickness, each slot 115 opening onto both the inner surface 111 and the outer surface 112 of the inner annular wall to allow airflow E to communicate with the annular cavity 130, with arrow E indicating the flow direction in the compressor and thus indicating its upstream and downstream sides.

[0029] Groove 115 is located in the inner annular wall 110 along the circumferential direction D C Evenly adjacent arrangement. Each slot 115 is along the axial direction D. A Extending over a defined length L115. In the example described herein, slot 115 is relative to the radial direction D. R Tilt 45°.

[0030] The known slot 115 and the annular cavity 130 it enters constitute a non-axisymmetric housing treatment (NACT) that can locally adjust the airflow to reduce mechanisms that cause compressor stall.

[0031] In this invention, the housing 100 further includes a sliding ring 140, which is contained within the annular cavity 130 and... Figure 6 The complete image is shown below. The sliding ring 140 can be positioned in the axial direction D. A The upper part moves between the open position and the closed position. In the open position, the groove 115 in the inner annular wall 110 of the housing opens into the annular cavity 130. Figure 1 and Figure 3 In the closed position, the sliding ring at least partially covers groove 115. Figure 2 and Figure 4In the closed position, the groove covered by the sliding ring does not open into the annular cavity.

[0032] More specifically, the sliding ring 140 extends along the outer surface 112 of the inner annular wall 110 in the axial direction D. A The sliding ring 140 moves upward. The axial length L140 of the sliding ring 140 is greater than or equal to the groove length L115. The length L140 of the ring 140 is also determined such that when the sliding ring is in the open position ( Figure 1 The annular cavity 130 is in the axial direction D A The length of the upper extension L130 is approximately equal to the length L115 of the slot 115.

[0033] In the example described here, the sliding ring 140 is a single piece, meaning that in the closed position, the ring covers all the slots 115 of the inner annular wall 110. In this case, no slots open into the annular cavity 130.

[0034] In one specific feature, the sliding ring 140 includes cavities 145 on its inner surface 141, which faces the outer surface 112 of the inner annular wall 110. These cavities 145 are positioned at defined points on the inner surface 141 of the sliding ring to ensure that the cavities 145 mate (align) with the groove 115 in the closed position. In the example described herein, the cavities 145 are oriented at 45°, similar to the groove 115.

[0035] The cavities 145 can take on various shapes. Specifically, they can have, for example... Figure 6 The aerodynamic shapes shown include crescent shapes. In the closed position, the sliding ring 140 with cavity 145 allows the aerodynamic shape to be imparted to the groove, thereby reducing losses.

[0036] The annular cavity 130 is closed on the upstream side by an upstream end portion 131 connecting the inner annular wall 110 and the outer annular wall 120, and on the downstream side by a removable downstream flange or end portion 132. The removable flange 132 includes one or more injection orifices 1320 that open into the annular cavity 130 opposite to the downstream face 143 of the sliding ring 140.

[0037] The housing 100 includes an actuation device, which is here constituted by an air injection system 10 connected to each injection orifice 1320. Pressurized airflow A is injected via each orifice 1320 to control the sliding ring 140 to the closed position. Figure 2 The removable flange 132 is provided with O-rings 133 and 134 to ensure a seal between the airflow and the external environment. Similarly, the sliding ring 140 is provided with O-rings 147 and 148 to ensure a seal between the ring and the external environment.

[0038] Furthermore, several recoil springs 20 are held in a compressed state between the upstream end portion 131 of the annular cavity 130 and the upstream surface 144 of the sliding ring 140. The recoil springs 20 are positioned within the annular cavity 130 along the circumferential direction D. C Uniformly distributed. As long as no pressurized air is ejected through the injection orifice 1320, the recoil spring 20 allows the sliding ring to remain in the open position.

[0039] In a variation of the embodiment, the sliding ring may be divided into several annular segments, which are individually slidable in the annular cavity along the axial direction. In this case, the downstream end portion or flange includes at least one injection orifice opposite to each annular segment. The actuation device still includes an air injection system, but this air injection system is selectively connected to each injection orifice, for example by means of a valve, so that pressurized air can be injected independently for each annular segment. Furthermore, each annular segment is slidable in guides on the outer surface of the inner annular wall and / or the inner surface of the outer annular wall of the housing. When the ring is provided with cavities, each annular segment includes multiple cavities, the number of which corresponds to the number of grooves in the portion of the inner annular wall to be covered.

[0040] Therefore, by selectively injecting compressed air, only a portion of the annular section can be controlled to move to the closed position, while the other annular sections are held in the open position by the recoil spring.

[0041] The actuation device is not limited to using a pressurized air injection system. The actuation device may also use a piston or cylinder housed in the removable flange 132, or any other suitable actuation system.

[0042] Regardless of the specific implementation, the grooves in the housing can be identical.

[0043] Regardless of the embodiment, the cavities of the sliding ring can be identical. Advantageously, the cavities of the sliding ring and the grooves of the housing have the same dimensions, i.e., they have the same length and width; and the distance between the grooves of the housing is equal to the distance between the corresponding cavities of the sliding ring. This allows the cavities of the sliding ring to mate (align) with the grooves of the housing.

[0044] Regardless of the implementation, the housing can be a single piece.

[0045] Regardless of the embodiment, the number of slots in the housing (and therefore the number of cavities in the sliding ring) is between 40 and 850, for example between 45 and 810, and even more specifically between 60 and 210. Housing processing requires 3 to 8 slots per rotor blade, and a rotor comprises 15 to 90 blades. Therefore, this range of values ​​covers all possibilities.

[0046] Regardless of the implementation, the housing and the sliding ring can be made of the same material. This allows both components to withstand the same thermal and mechanical stresses, ensuring that the opening or closing of the housing slots is always feasible even under conditions of thermal expansion.

[0047] Alternatively, the housing and sliding ring can be made of different materials, but the two materials must have similar or even identical physical properties so that they experience similar thermal expansion.

[0048] The expression “between… and…” should be understood to include both endpoints.

Claims

1. A casing (100) of a turbine engine compressor (300), the casing comprising an inner annular wall (110) and an outer annular wall (120) defining between them an annular cavity (130), the inner annular wall (110) of the casing comprising a plurality of slots (115) dug in the thickness of the inner annular wall, the slots being arranged adjacent to each other in a circumferential direction (D C ), and each slot extending in an axial direction (D A ), the casing further comprising a sliding ring (140) present inside the annular cavity (130) of the casing, the sliding ring being movable in the axial direction (D A ) between an open position in which the slots (115) in the inner annular wall (110) of the casing are open into the annular cavity (130), and a closed position in which the sliding ring (140) covers at least some of the slots (115). The housing further comprises actuating means to move the sliding ring (140) between the open position and the closed position, characterized in that, Said sliding ring (140) comprises a cavity (145) on its inner surface (141) opposite the outer surface (112) of said inner annular wall (110), said cavity being located at a determined point on said inner surface of said sliding ring so that, in said closed position, said cavity (145) coincides with said slot (115).

2. The housing of claim 1, wherein Said sliding ring (140) is formed as a single piece.

3. The housing of claim 2, wherein, Said actuation device comprises a pressurized air injection system (10) in communication with one or more injection orifices (1320) in a downstream end portion (132) of said annular cavity (130), a plurality of springs (20) being held in compression between an upstream end portion (131) of said annular cavity and said sliding ring (140).

4. The case according to claim 1, characterized by Said sliding ring is divided into several annular segments that can slide independently within said annular cavity in said axial direction.

5. The housing of claim 4, wherein, Said actuation device comprises a pressurized air injection system in communication with at least one injection orifice provided in a downstream end portion of an annular cavity, said injection orifice being opposite each annular segment of said sliding ring, at least one spring being held in compression between an upstream end portion of said annular cavity and each annular segment of said sliding ring.

6. The housing according to any one of claims 1 to 5, characterized in that Said cavity (145) of said sliding ring (140) has an aerodynamic shape.

7. The housing of any one of claims 1 to 6, wherein, Said cavity (145) of said sliding ring (140) and said slot (115) of said casing have the same dimensions.

8. A turbomachine compressor (300) comprising a casing (100) according to any one of claims 1 to 7.

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