CN217582609U - Axial flow compressor of cantilever type adjustable stator and aeroengine - Google Patents

Abstract

The utility model provides an adjustable stator of cantilever type for the compressor, including rotation axis, stator blade and a plurality of water conservancy diversion rib. The rotating shaft is arranged to be rotatably mounted to a casing through a mounting hole of the casing of the compressor, whereby the rotating shaft has an outer end surface extending outside the casing and an inner end surface extending inside the casing, and the cantilever-type adjustable stator is suspended to the casing. The stator blade has a tip and a root, and defines a chord direction and a blade height direction, the tip being connected to an inner end surface of the rotating shaft. The guide ribs are discretely distributed on the root bottom surface of the blade root of the stator blade, extend along the chord direction, and are less than 2mm in height in the blade height direction. The utility model also provides an aeroengine axial compressor of the adjustable stator of above-mentioned cantilever type. The cantilever type adjustable stator can simplify the structure and reduce the aerodynamic loss.

Description

Axial flow compressor of cantilever type adjustable stator and aeroengine

Technical Field

The utility model relates to an adjustable stator of cantilever type for the compressor still relates to an aeroengine axial compressor.

Background

The wide-body passenger plane engine technology represents the most advanced technical level of world civil aviation engines, different working states of large-scale aviation engines correspond to different rotating speeds, the rotating speed of the engines is rapidly increased from zero in the starting process, and if front-stage stator blades of the air compressor adopt fixed angles under different rotating speeds, the efficiency of the air compressor is reduced, and surging of the air compressor can be induced. The front stage of the compressor is designed by adopting adjustable Stator blades (VSV), the VSV angle can be optimized at corresponding rotating speed, the compressor works at the optimal efficiency point under different rotating speed states, and the surge problem of the aircraft engine under the low rotating speed working condition in the starting process can be avoided.

However, the conventional compressor inlet adjustable stator blade root in the current aircraft engine has the problems of complex structure, difficult processing, high cost and easy clamping stagnation. In addition, the root of the conventional adjustable stator blade has the problems of mutual coupling of secondary flows, complex structure of a root flow field and high aerodynamic loss.

Therefore, there is a need to design a VSV structure that can reduce aerodynamic losses while simplifying the structure.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a cantilever type adjustable stator can reduce aerodynamic loss when simplifying the structure.

The utility model provides an adjustable stator of cantilever type for the compressor, including rotation axis, stator blade and a plurality of water conservancy diversion rib. A rotary shaft is arranged to be rotatably mounted to a casing of the compressor through a mounting hole of the casing, whereby the rotary shaft has an outer end surface protruding outside the casing and an inner end surface protruding inside the casing, and the cantilevered adjustable stator is suspended from the casing. The stator blade has a tip and a root, and defines a chord direction and a blade height direction, the tip being connected to the inner end surface of the rotating shaft. The plurality of guide ribs are discretely distributed on the root bottom surface of the blade root of the stator blade, the guide ribs extend along the chord direction, and the height of the guide ribs in the blade height direction is smaller than 2mm.

In one embodiment, the tip has a front portion and a rear portion in a chord direction, the tip being connected to the inner end surface of the rotary shaft through the front portion. The front side portion is more than the rear side portion.

In one embodiment, the front portion is higher than the rear portion in the blade height direction, whereby a step is formed on the blade tip.

In one embodiment, the rotating shaft has an outer shaft section that protrudes outside the casing, provides the outer end face, and has a first shaft section and a second shaft section on the bottom side and the top side, respectively, in the blade height direction, the second shaft section having a smaller shaft diameter than the first shaft section.

In one embodiment, the mounting hole of the casing has a first hole section and a second hole section respectively located at the bottom side and the top side in the blade height direction, and the hole diameter of the second hole section is smaller than that of the first hole section. The rotating shaft also has a middle shaft section and an inner shaft section. The intermediate shaft segment is rotatably fitted within the second bore segment. The intermediate shaft section connects the inner shaft section and the outer shaft section, the inner shaft section rotatably fitting within the first bore section.

In one embodiment, the flow guide ribs are straight ribs, bent ribs, rounded ribs and/or airfoil ribs.

In one embodiment, the cantilevered adjustable stator is integrally formed.

In one embodiment, the height of the flow guide ribs is greater than or equal to 1mm.

The utility model also provides an aeroengine axial compressor, including the adjustable stator of casket, rotor dish and cantilever type. The rotor disk has a hub. The cantilever type adjustable stator is rotatably suspended in the casing, a root bottom surface of a stator blade of the cantilever type adjustable stator is opposite to the hub, and a maximum gap between the root bottom surface and the hub is smaller than or equal to 2.0mm.

In one embodiment, the hub is provided with a wear resistant coating.

The cantilever type adjustable stator is rotatably arranged on the casing through the rotating shaft and adopts a cantilever supporting structure, and meanwhile, the blade root of the stator blade is provided with the small flow guide rib with the height smaller than 2mm, so that the structure can be simplified and the aerodynamic loss can be reduced.

Drawings

The above and other features, properties and advantages of the present invention will become more apparent from the following description of the embodiments with reference to the accompanying drawings, in which:

fig. 1 is a schematic diagram of a conventional compressor.

Fig. 2 is a schematic diagram of an exemplary compressor according to the present invention.

Fig. 3 is a schematic diagram of an exemplary cantilever adjustable stator according to the present invention.

Fig. 4A, 4B, 4C, and 4D are schematic views respectively showing different forms of guide ribs.

Detailed Description

The present invention will be further described with reference to the following detailed description and the accompanying drawings, wherein more details are set forth in the following description in order to provide a thorough understanding of the present invention, but it is apparent that the present invention can be implemented in many other ways than those described herein, and those skilled in the art can similarly popularize and deduce according to the practical application without departing from the spirit of the present invention, and therefore the scope of the present invention should not be limited by the contents of this detailed description.

For example, a first feature described later in the specification may be formed over or on a second feature, and may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact. Further, when a first element is described as being coupled or coupled to a second element, the description includes embodiments in which the first and second elements are directly coupled or coupled to each other, as well as embodiments in which one or more additional intervening elements are added to indirectly couple or couple the first and second elements to each other.

Fig. 1 shows an example structure of a conventional adjustable stator 10a, taking an example of a stage of an inlet adjustable stator in a high-speed axial compressor 100a of an aircraft engine. The blade root of the conventional adjustable stator 10a is configured in such a manner that the leading edge part of the stator blade 2a is fused with the rotating shaft 1a, a partial gap exists between the trailing edge of the blade and the root runner, and the honeycomb structure 60a is arranged at the position of the sealing ring. The structure at the honeycomb 60a may also be referred to as an inner ring and a honeycomb seal ring. For example, a gap value δ 1 between the trailing edge of the blade and the flange plate is =1.0mm, and a gap value δ 2 between the comb teeth 302 of the rotor disk 30 and the flange plate honeycomb structure 60a is =1.0mm.

Fig. 1 also shows an engine rotation axis O1. In fig. 1, the rotor blades 50a are disposed on the rotor disc 30a, and the adjustable stator 10a is disposed between two adjacent rotor blades 50 a. The rotary shaft 1a is rotatably mounted to the casing 20a, and its rotation angle can be adjusted by the rocker arm 70 a. It is to be understood that the drawings are designed solely for purposes of illustration and not as an aid to scale, and should not be construed as limiting the scope of the invention in any way.

The conventional VSV is complex in structure, difficult to manufacture and high in cost, clamping stagnation even occurs at partial rotating speed, most seriously, root clearance leakage flow and grate tooth leakage flow exist in the conventional VSV blade, the two leakage flows are mutually coupled to form a very complex root three-dimensional flow structure, a numerical simulation method cannot accurately simulate root secondary flow of the VSV, a conventional VSV root structure is complex, a measuring instrument cannot accurately measure a detailed flow field at the root, the flow condition of the VSV root cannot be accurately evaluated by the numerical method and the test method, and great trouble is brought to pneumatic design work of an air compressor.

The utility model discloses to the above-mentioned not enough that prior art exists, provide an adjustable stator of cantilever type that blade root has little rib, the VSV blade that obtains can avoid the labyrinth to leak and flow to have simple structure's advantage, reduce manufacturing process complexity and practice thrift the cost.

The present invention provides a cantilever type adjustable stator 10 as shown in fig. 2 and 3. In describing the embodiment of the present invention, the same reference numerals as those of the conventional adjustable stator 10a shown in fig. 1 are used to omit a part of the similar description.

Referring to fig. 2 and 3, a cantilever-type adjustable stator 10 is used in a compressor 100. The cantilever-type adjustable stator 10 includes a rotating shaft 1, a stator blade 2, and a plurality of guide ribs 3. It is understood that "plurality" herein means more than two, including two, three, four, five, etc.

The rotary shaft 1 is provided to be rotatably mounted to the casing 20 through a mounting hole 201 of the casing 20 of the compressor 100, whereby the rotary shaft 1 has an outer end surface 11 protruding outside the casing 20 and an inner end surface 12 protruding inside the casing 20, and the cantilevered adjustable stator 10 is suspended from the casing 20.

The stator blade 2 has a tip 21 and a root 22, and defines a chord direction X1 and a blade height direction H1. The blade tip 21 may be connected to the inner end surface 11 of the rotating shaft 1.

It can be understood that the cantilever-type adjustable stator 10 is cantilever-supported by rotatably mounting one end of the rotary shaft 1 to the casing 20. That is, the end of the blade root 22 of the stator blade 2 of the cantilevered adjustable stator 10 is unsupported.

The aforementioned plurality of guide ribs 3 (shown in fig. 3) are discretely distributed on the root bottom surface 220 of the blade root 22 of the stator blade 2. The guide ribs 3 extend in the chord direction X1. The height of the flow guide ribs 3 in the blade height direction H1 is less than 2mm. In fig. 2, the flow guide ribs 3 are not shown for the sake of simplicity of illustration.

It will be understood that reference herein to "along" a direction means that there is at least a component in that direction, preferably within 45 ° of that direction, more preferably within 20 °. For example, here, the flow guiding rib 3 has at least a component in the chord direction X1 along the chord direction X1, that is, the rib length direction of the flow guiding rib 3 is within 45 ° of the chord direction X1.

Compared with the conventional adjustable stator which is provided with a labyrinth inner ring and a partial gap exists between the blade root and the hub, the cantilever type adjustable stator 10 adopts a cantilever structure form at the root, and the small flow guide ribs 3 with the height of less than 2mm are arranged on the root bottom surface 220 of the blade root 22 of the stator blade 2, so that the structural complexity can be reduced, the manufacturing cost can be reduced, and the flow loss of the blade root of the adjustable stator can be effectively reduced.

In fig. 2, the tip 21 may have a front side portion 211 and a rear side portion 212 in the chord direction X0. The blade tip 21 may be connected to the inner end face 11 of the rotating shaft 1 through the front side portion 211.

Further, in fig. 2, there may be more front side portions 211 than rear side portions 212. That is, the front side portion 211 of the tip 21 connected to the rotating shaft 1 occupies most of the area of the tip 21.

It is to be understood that "forward", "aft", etc. herein are with respect to the direction of flow of the gas flow through the compressor 100, with the upstream position leading at a downstream position and the downstream position trailing or aft at an upstream position. The front side portion 211 includes a leading edge portion of the stator blade 2, and the rear side portion 212 includes a trailing edge portion of the stator blade 2.

In fig. 2, the front side portion 211 may be higher than the rear side portion 212 in the blade height direction H1, whereby a step may be formed on the blade tip 21. That is, the blade tip 21 takes the form of a step descending from front to back.

In fig. 2, the rotating shaft 1 may have an outer shaft section 13. The outer shaft section 13 may protrude outside the casing 20, provide an outer end face 11, and may have a first shaft section 131 and a second shaft section 132 on the bottom side and the top side, respectively, in the blade height direction H1. The shaft diameter of the second shaft segment 132 may be smaller than the shaft diameter of the first shaft segment 131.

In fig. 2, the mounting hole 201 of the casing 20 may have a first hole section 2011 and a second hole section 2012 respectively located at the bottom side and the top side in the blade height direction H1. The aperture of second bore section 2012 may be smaller than the aperture of first bore section 2011.

In fig. 2, the inner end surface 11 of the rotating shaft 1 may have a front portion 111 and a rear portion 112 in the chord direction X1. The inner end face 11 can be connected to the tip 21 of the stator blade 2 by a rear portion 112. The front portion 111 may be less than the rear portion 112. That is, the rear portion 112 of the rotary shaft 1 connecting the tip 21 occupies most of the area of the inner end surface 11.

The rotating shaft 1 may also have an intermediate shaft section 14. The middle shaft segment 14 may be rotatably fitted within the second bore segment 2012 of the mounting bore 201.

The rotating shaft 1 may also have an inner shaft section 15. The intermediate shaft segment 14 may connect the inner shaft segment 15 and the outer shaft segment 13. The inner shaft segment 15 may be rotatably fitted within the first bore segment 2012.

Referring to fig. 4A to 4D, the guide ribs 3 may be straight ribs (shown in fig. 4A), bent ribs (shown in fig. 4B), arc ribs (shown in fig. 4C), and/or airfoil ribs (shown in fig. 4D). The airfoil ribs in FIG. 4D may be B-Spline or Spline-Spline curvilinear ribs. For various forms of the guide ribs 3, the rib length direction D1 may be considered as a direction coinciding with a line connecting two points of the guide ribs 3 that are farthest apart. Fig. 4B and 4C also show the bending angle α of the bending rib and the central angle β of the circular-arc rib, respectively.

The shape of the small ribs such as the guide ribs 3 arranged on the blade root can be different. As mentioned above, the shape of the guide ribs 3 may be defined according to the shape of the arcs therein. The position of the guide ribs 3 may be appropriately arranged according to the thickness of the blade root. The number of packs arranged may be a single row, a double row, multiple rows, etc.

As shown in fig. 3, the cantilevered adjustable stator 10 may be integrally formed.

In one embodiment, the height of the flow guide ribs 3 may be greater than or equal to 1mm, that is, not less than 1mm.

It is understood that the use of particular words herein to describe embodiments of the invention, such as "one embodiment," "another embodiment," and/or "some embodiments" means that a particular feature, structure, or characteristic described in connection with at least one embodiment of the invention is included. Therefore, it is emphasized and should be appreciated that two or more references to "one embodiment" or "another embodiment" in various places throughout this specification are not necessarily to the same embodiment. Furthermore, certain features, structures, or characteristics of one or more embodiments of the invention may be combined as appropriate.

When the cantilever type adjustable stator is actually designed, on the basis of a conventional adjustable stator, firstly, the blades are changed into the cantilever type and matched with the rotating hub, and modeling, grid division, numerical simulation, data processing and flow field analysis are carried out after a proper root gap value is selected. Secondly, carrying out blade geometric optimization to obtain a primary cantilever type adjustable stator blade and ensure that the aerodynamic loss of the blade is not higher than that of a conventional stator blade. And finally, carrying out micro-rib design on the root part of the cantilever type adjustable static blade to obtain a final VSV design scheme.

Specific exemplary design steps are described below.

Firstly, determining the hub modeling under the structural scheme of the cantilever type adjustable stator blade: based on the conventional adjustable stator in fig. 1, the rotor disc is adjusted, the hub modeling of front and rear adjacent rotors is combined, the hub molded line below the cantilever adjustable stator is initially modeled by adopting a 'Spline' curve, the smooth and continuous hub curve is ensured, and the connection between the hub at the root of the stator and the adjacent rotors is ensured.

Secondly, determining a root clearance value of the cantilever type adjustable stator blade. From the trailing edge root clearance value δ 1 and the labyrinth clearance value δ 2 of the conventional adjustable stator, the cantilevered adjustable stator blade root clearance value δ is determined, and δ ≦ δ 1+ δ 2, e.g., δ 1+ δ 2=2.0mm.

Then, modeling, grid division and steady RANS numerical simulation are carried out according to the cantilever type adjustable stators and the root gap values corresponding to the cantilever type adjustable stators, and data processing and flow field analysis are carried out. Wherein the grid is divided, e.g. O4H grid is used as main flow area of cantilever type adjustable stator blade passage, and butterfly is used in gap between blade root and hubThe height of the first layer of grid is 1 x 10 ^-6 m, growth rate set to 1.1, maintaining orthogonality > 20 °. In data processing and flow field analysis, for example, data processing is performed on the flow field of the cantilever type adjustable stator blade, and relevant flow field pneumatic parameters including a total pressure loss coefficient, a blade surface pressure coefficient and the like are analyzed.

And then, acquiring a flow field in the VSV root range according to the pneumatic flow field analysis in the previous step, determining the main source of loss, and reducing the pneumatic loss of the root as much as possible by optimizing the blade stacking rule, the interstage matching rule, the mean camber line distribution and the like.

The arrangement of such small ribs at the blade root can be used to improve the effect of root leakage flow. The root leakage flow is mixed with the main flow due to the root clearance, so that certain difficulty is brought to the interstage matching of a downstream rotor, and the loss brought by the leakage flow is reduced. The radial height of the minute ribs may be selected depending on the machining accuracy, and as described above, the height value is preferably not less than 1mm.

As shown in fig. 2, the present invention provides an aircraft engine axial flow compressor 100 that may include a casing 20, a rotor disc 30, and a cantilevered adjustable stator 10.

The rotor disk 30 can have a hub 301. The cantilevered adjustable stator 10 may be rotatably suspended from the case 20. The root surface 220 of the stator blade 2 of the cantilever-type adjustable stator 10 may be opposite to the hub 301. The maximum clearance between the root floor 220 and the hub 301 may be less than or equal to 2.0mm.

When the clearance value that adjustable stator blade 2 adopted is less than or equal to 2.0mm, can both guarantee sufficient clearance and make and avoid taking place the condition that scraping, jamming take place for blade 2 piece and wheel hub 301 in angle modulation scope, guarantee the pneumatic loss that the clearance value that is as little as possible caused in order to reduce the leakage flow again. Further preferably, the gap between the root bottom surface 220 and the hub 301 may be 1.5mm.

In one embodiment, hub 301 may be provided with a wear resistant coating. This may further reduce the root clearance value, which, in combination with the micro-rib design, may maintain the total pressure loss at the root at a lower level and improve the inlet profile of the downstream rotor.

In fig. 2, the hub 301 may be maintained in a flat state between adjacent buckets 50. It will be appreciated that in essence, the hub 301 is a surface of revolution between adjacent buckets 50, and that the hub 301 remains straight, i.e., the generatrix of the surface of revolution is substantially straight rather than curved as shown in FIG. 1. That is, the hub at the position of the adjustable stator blade root has a smooth and continuous profile with the hub profile of the adjacent rotor blade.

When the cantilever type adjustable stator is adopted, the root structure of the imported adjustable stator can be greatly simplified, the manufacturing cost and the later maintenance cost are saved, the clamping stagnation condition of the root can be avoided, the root flow field can be improved, and the pneumatic loss is reduced.

Although the preferred embodiments of the present invention have been disclosed, the present invention is not limited thereto, and those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent changes and modifications made to the above embodiments according to the technical spirit of the present invention, all without departing from the content of the technical solution of the present invention, fall within the scope of protection defined by the claims of the present invention.

Claims (10)

1. A cantilevered adjustable stator for a compressor, comprising:

a rotating shaft disposed to be rotatably mounted to a casing of the compressor through a mounting hole of the casing, whereby the rotating shaft has an outer end surface protruding outside the casing and an inner end surface protruding inside the casing, and the cantilevered adjustable stator is suspended to the casing;

stator blades having a tip and a root, the tip connecting the inner end surface of the rotating shaft, and defining a chord direction and a blade height direction; and

the guide ribs are discretely distributed on the root bottom surface of the blade root of the stator blade, extend along the chord direction, and are less than 2mm in height in the blade height direction.

2. The cantilevered adjustable stator of claim 1 wherein the She Dingyan chordwise has a front portion and a rear portion, the tip being connected to the inner end face of the rotating shaft by the front portion;

the front side portion is more than the rear side portion.

3. The cantilevered adjustable stator of claim 2,

the front side portion is higher than the rear side portion in the blade height direction, whereby a step is formed on the blade tip.

4. The cantilevered adjustable stator of claim 1, wherein said rotating shaft has an outer shaft section that protrudes outside said casing, provides said outer end face, and has a first shaft section and a second shaft section at a bottom side and a top side, respectively, in a blade height direction, said second shaft section having a smaller shaft diameter than said first shaft section.

5. The cantilevered adjustable stator of claim 4, wherein the mounting hole of the casing has a first hole section and a second hole section at a bottom side and a top side, respectively, in a blade height direction, the second hole section having a smaller hole diameter than the first hole section;

the rotating shaft further has:

a middle shaft section rotatably fitted within the second bore section; and

an inner shaft section connecting the inner shaft section and the outer shaft section, the inner shaft section rotatably fitting within the first bore section.

6. The cantilever-type adjustable stator of claim 1, wherein the flow guide rib is a straight rib, a bent rib, a circular rib and/or an airfoil rib.

7. The cantilevered adjustable stator of claim 1 wherein said cantilevered adjustable stator is integrally formed.

8. The cantilevered adjustable stator of claim 1 wherein the height of the guide rib is greater than or equal to 1mm.

9. An axial compressor for an aircraft engine, comprising:

a case;

a rotor disk having a hub; and

the cantilevered adjustable stator as claimed in any one of claims 1 to 8, rotatably suspended from the casing, a root face of a stator blade of the cantilevered adjustable stator being opposite the hub, a maximum clearance between the root face and the hub being less than or equal to 2.0mm.

10. An axial flow compressor for aircraft engines, as claimed in claim 9, characterised in that the hub is provided with a wear-resistant coating.

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