CN112049818B

CN112049818B - Compressor and compressor blade

Info

Publication number: CN112049818B
Application number: CN201910491297.9A
Authority: CN
Inventors: 强艳; 张晓诗; 吴帆; 杨俊�; 曹艺
Original assignee: AECC Commercial Aircraft Engine Co Ltd
Current assignee: AECC Commercial Aircraft Engine Co Ltd
Priority date: 2019-06-06
Filing date: 2019-06-06
Publication date: 2022-04-26
Anticipated expiration: 2039-06-06
Also published as: CN112049818A

Abstract

The object of the present invention is to provide a compressor blade which achieves a relatively better aerodynamic performance than known compressor blades. Another object of the present invention is to provide a compressor comprising the above compressor blade. In order to achieve the purpose, the compressor blade comprises a blade body and a flange plate connected with the blade top or the blade root of the blade body, wherein the joint of the blade body and the flange plate is in transition through a fillet, the fillet adopts a small chamfer radius at the front edge of the blade body, and the chamfer radius is gradually increased from the front edge of the blade body to the tail edge of the blade. Wherein the fillet has a connection length L with the endwall of the platform, a height H with the blade body, an included angle α with the endwall and an included angle β with the surface of the blade body, L, H, α, β increasing progressively from the leading edge to the trailing edge.

Description

Compressor and compressor blade

Technical Field

The invention relates to a compressor and a blade thereof.

Background

In an actual axial flow compressor, due to the influence of machining process and strength factor, the root of the movable blade and the root tip of the stationary blade are usually chamfered, as shown in fig. 1 and fig. 2, which respectively show a perspective view and a top view of the conventional blade, it can be seen that the blades 8 shown in fig. 1 and fig. 2 are both chamfered 9, and the chamfers 9 are shown as being symmetrical. Fig. 3 is a schematic view of the prior art blade fillet shape, and the shape of the chamfer 9 is shown as being equal to the angle R formed by the end wall 91 and the blade airfoil surface 92.

According to the research of the inventor, after the multi-stage axial flow compressor is added with the movable and fixed blade chamfering structure, under the chamfering effect, the distribution of vortex systems in a cascade flow field is changed, vortexes of an upper channel and a lower channel migrate towards the middle blade span direction, the strength of the vortexes at the end wall is increased, the loss of secondary flow is increased, and when the chamfering radius is increased to a certain degree, the flow and the performance of the compressor are obviously reduced. From the front edge to the tail edge, the influence range of the chamfer angle on the flow field is gradually enlarged along the flow direction, the outlet section influences the flow field with a larger range of the root tip, and secondary flow loss at the root and the top and lower channel vortex loss are caused to rise. Especially for the outlet stage blade of a high-load high-stage pressure ratio compressor and the blade of a low-flow compressor, the height of the blade is small, and the ratio of the chamfer radius in the blade height is high, so that the flow influence on the blade passage is larger.

Disclosure of Invention

The object of the present invention is to provide a compressor blade which achieves a relatively better aerodynamic performance than known compressor blades.

Another object of the present invention is to provide a compressor comprising the above compressor blade.

In order to achieve the purpose, the compressor blade comprises a blade body and an edge plate connected with the blade top or the blade root of the blade body, wherein the joint of the blade body and the edge plate is transited by a fillet, the fillet adopts a small chamfer radius at the front edge of the blade body, and the chamfer radius is gradually increased from the front edge of the blade body to the tail edge of the blade, wherein the fillet has a connection length L with the end wall surface of the edge plate, a height H connected with the blade body, an included angle alpha formed by the end wall surface and an included angle beta formed by the surface of the blade body, and L, H, alpha and beta are gradually increased from the front edge to the tail edge.

In one or more embodiments, a chamfer radius on a pressure surface side of the blade body is larger than a chamfer radius on a suction surface side at the same chordwise position of the blade body.

In one or more embodiments, a control point is provided at the maximum thickness of the blade airfoil, ensuring that L, H is greater on the pressure side of the airfoil than on the suction side.

In one or more embodiments, a control point is placed at the trailing edge to ensure that H is greater than L and β is less than α.

In one or more embodiments, a control point is provided at the leading edge to ensure L, H, α, β are minimal at the leading edge.

In one or more embodiments, the compressor blade is a vane or a blade of a compressor.

The compressor for achieving the other purpose comprises a plurality of compressor blades, and the compressor blades are the compressor blades as described above.

In one or more embodiments, the compressor is a multi-stage axial compressor, and the compressor blades are outlet stage blades.

In one or more embodiments, the compressor is a low flow compressor.

The gain effect of the invention is that: the fillet at the joint of the blade body and the flange plate of the compressor blade is configured to be gradually increased from the front edge to the tail edge of the blade body, the camber line at the end part of the blade is changed, so that the attack angle of the front edge of the blade is increased, when the blade is installed on the compressor, the throat area of the front edge of the adjacent blade is increased, the secondary flow loss in a channel is reduced, and the working capacity of the blade top or the blade root part of the compressor blade connected with the flange plate is increased under the condition of ensuring the original circulation capacity. Meanwhile, the flow field at the tail edge of the blade is optimized, the low-speed area at the tail edge is reduced, the outlet airflow is more uniform, so that relatively better pneumatic performance is obtained, and the performance of the compressor is improved.

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 illustrates a perspective view of a prior art compressor blade;

FIG. 2 illustrates a schematic top view of a prior art compressor blade;

FIG. 3 is a schematic view illustrating a prior art compressor blade fillet shape definition;

FIG. 4 illustrates a schematic perspective view of an embodiment of a compressor blade;

FIG. 5 is a schematic top view of a compressor blade;

FIG. 6 is a schematic diagram of compressor blade fillet shape control point distribution;

FIG. 7 is a schematic view of a compressor blade fillet shape definition.

Detailed Description

The following discloses many different embodiments or examples for implementing the subject technology described. Specific examples of components and arrangements are described below to simplify the present disclosure, but these are merely examples and do not limit the scope of the invention. For example, if a first feature is formed over or on a second feature described later in the specification, this 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. Additionally, reference numerals and/or letters may be repeated among the various examples throughout this disclosure. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. 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.

It should be noted that, where used, the following description of upper, lower, left, right, front, rear, top, bottom, positive, negative, clockwise, and counterclockwise are used for convenience only and do not imply any particular fixed orientation. In fact, they are used to reflect the relative position and/or orientation between the various parts of the object.

The following embodiments take an Axial compressor (Axial compressor) as an example, and the air flow of the Axial compressor is in a compressor with the flow direction of the meridian plane substantially parallel to the axis of the rotor. The high-pressure air compressor is formed by alternately arranging a series of stators and rotors, is used for conveying and compressing air and is used for a high-pressure air compressor of an aircraft engine. The multistage axial flow compressor is composed of two parts, wherein the rotating part is called a rotor, and the non-moving part is called a stator. The rotor is assembled from a plurality of discs having a plurality of blades mounted along the circumference of the disc, each disc together with the blades mounted thereon being referred to as a rotor wheel, the blades of which are referred to as buckets. The stator of a multistage axial compressor is composed of a plurality of rows of blades fixed on a casing, each row of blades is called a rectifier, and the blades on the rectifier are called stationary blades. The flow direction in the flow phenomena of the cross flow in the boundary layer of the annular wall, the backflow in the radial gap, the undercurrent of the boundary layer on the blade profile, the gap vortex, the channel vortex and the like is not consistent with the main flow direction, so the flow phenomena are commonly called secondary flow, and the loss caused by the secondary flow is called secondary loss. The chamfer and fillet at the blade root or the blade tip are the characteristics for smooth transition of the blade and the flow passage surface.

Fig. 4 shows a perspective view of an embodiment of a compressor blade, and fig. 5 is a top view of a compressor blade, wherein fig. 5 can be seen as the compressor blade of fig. 4 from a top view. The compressor blade 1 comprises a blade body 10 and an edge plate 11 connected with a blade root 15 of the blade body 10, wherein the joint of the blade body 10 and the edge plate 11 is transited by a fillet 2. In an embodiment different from that shown, the platform 11 may also be connected to the tip 16 of the blade body 10, and the connection is rounded.

Wherein, the leading edge 10a of the blade body 10 of the fillet 2 adopts a small chamfer radius, and simultaneously, the chamfer radius of the fillet 2 is gradually increased from the leading edge 10a to the trailing edge 10b of the blade body 10. Wherein it is understood that the chamfer radius refers to the radius of the arc segment in the fillet 2.

Compared with the conventional compressor blade shown in fig. 1 to 3, the compressor blade has the advantages that the fillet 2 at the joint of the blade body 10 and the flange plate 11 is configured to be gradually increased from the front edge 10a to the tail edge 10b of the blade body 10, the camber line at the end part of the blade is changed, so that the attack angle of the front edge 10a of the blade is increased, the throat area of the front edge 10a of the blade is increased, the secondary flow loss in the channel is reduced, and the power-doing capacity of the blade top or the blade root part of the compressor blade 1 connected with the flange plate 11 is increased under the condition of ensuring the original flow capacity. Meanwhile, the flow field at the tail edge 10b is optimized, the low-speed area at the tail edge 10b is reduced, and the outlet airflow is more uniform, so that relatively better pneumatic performance is obtained, and the performance of the compressor is improved.

Although one embodiment of the present compressor blade is described above, in other embodiments of the present compressor blade, the compressor blade may have many more details than the above-described embodiments, and at least some of these details may have various variations. At least some of these details and variations are described below in several embodiments.

Fig. 6 is a schematic diagram of a compressor blade fillet shape control point distribution, wherein fig. 6 can be regarded as a schematic diagram of the compressor blade fillet shape control point distribution in fig. 4 and 5, please refer to fig. 4 to 6 in combination. In one embodiment of the compressor blade, the fillet 2 has a larger chamfer radius on the pressure side 101 than on the suction side 102 of the blade body 10 at the same chordwise (direction from the leading edge 10a to the trailing edge 10 b) position of the blade body 10, further increasing the throat area of the blade leading edge 10a for relatively better aerodynamic performance. Wherein, the pressure surface of the blade refers to the concave surface of the blade, namely the surface of a blade basin; the suction side of the blade refers to the convex side of the blade, i.e. the blade back surface.

Fig. 7 is a schematic view of the compressor blade fillet shape definition, wherein fig. 6 can be viewed as defining the compressor blade fillet shape of fig. 4 and 5, the compressor blade fillet shape being defined by L, H, α, β parameters as shown. Wherein, L is the length that fillet 2 and end wall face 110 of flange 11 are connected, H is the height that fillet 2 and blade 10 are connected, alpha is the contained angle that fillet 2 and end wall face 110 formed, and beta is the contained angle that fillet 2 and blade 10 surface formed.

With continued reference to fig. 7, a control point u is set at the leading edge 10a of the compressor blade, a control point z is set at the trailing edge 10b, a control point x is set at the suction surface of the blade body 10 at the maximum thickness, a control point y is set at the pressure surface of the blade body 10 at the maximum thickness, and the fillet shape of the compressor blade is controlled by controlling the values of the four parameters L, H, α, β of the fillet shape of the compressor blade at each control point.

Referring to fig. 6 and 7, as can be seen from fig. 6, when the included angles α and β decrease, the cross-sectional area of the fillet 2 also decreases, and correspondingly, when the included angles α and β gradually increase, the cross-sectional area of the fillet 2 also gradually increases. In one embodiment of the compressor blade, the parameters L, H, α, β increase in magnitude from the leading edge 10a to the trailing edge 10b of the blade. By adopting smaller L and H values at the leading edge 10a of the blade, the attack angle of the leading edge 10a of the blade of the compressor at the end wall surface 110 of the flange plate 11 can be adjusted, so that the working capacity of the blade top or the blade root connected with the flange plate 11 can be increased, the throat area of the leading edge 10a of the blade is increased, and the reduction of the flow rate blocked by the compressor is avoided.

In one embodiment of the compressor blade, the control point x is arranged on the suction surface at the maximum thickness of the blade body 10, and the control point y is arranged on the pressure surface at the maximum thickness of the blade body 10, so that the value of L, H of the blade body 10 on the pressure surface side 101 is larger than that on the suction surface side 102, the condition that the airflow angle is deviated to the pressure surface side 101 due to the fillet 2 at the blade top or the blade root where the blade body 10 is connected with the flange plate 11 can be relieved, the excessive rotation of the airflow angle at the outlet of the blade top or the blade root where the blade body 10 is connected with the flange plate 11 is avoided, and the separation loss of the surge point is reduced.

In one embodiment of the compressor blade, the control point z is set at the trailing edge 10b to ensure that the value of H is greater than the value of L and the included angle β is less than the included angle α, which is advantageous for the uniformity of the outlet flow field.

In one embodiment of the compressor blade, the control point u is set at the leading edge 10a of the compressor blade to ensure that the values of the parameters L, H, α, β are minimized at the leading edge 10 a.

In one embodiment of the compressor blade, the compressor blade 1 may be a stationary blade or a movable blade in the compressor.

The compressor blade according to one or more of the above embodiments may be applied to a compressor. In one embodiment of the compressor, the compressor may be a multi-stage axial compressor, and the compressor blades 1 are outlet stage blades in the axial compressor.

In one embodiment of the compressor, the compressor is a low-flow compressor, wherein a compressor with a flow rate of 10kg/s or less is counted as the low-flow compressor.

Although the present invention has been disclosed in terms of the preferred embodiment, it is not intended to limit the invention, and variations and modifications may be made by one skilled in the art without departing from the spirit and scope of the invention. Therefore, any modification, equivalent change and modification of the above embodiments according to the technical essence of the present invention are within the protection scope defined by the claims of the present invention, unless the technical essence of the present invention departs from the content of the present invention.

Claims

1. The compressor blade comprises a blade body and a flange plate connected with the blade top or the blade root of the blade body, wherein the joint of the blade body and the flange plate is in fillet transition, the fillet adopts a small chamfer radius at the front edge of the blade body, the chamfer radius is gradually increased from the front edge of the blade body to the tail edge of the blade body,

the fillet has a connection length L with the end wall surface of the flange plate, a height H connected with the blade body, an included angle alpha formed by the end wall surface and an included angle beta formed by the surface of the blade body, and L, H, alpha and beta are gradually increased from the front edge of the blade body to the tail edge of the blade body.

2. The compressor blade of claim 1 wherein a chamfer radius on the pressure side of the blade airfoil is greater than a chamfer radius on the suction side at the same chordwise location of the blade airfoil.

3. The compressor blade as in claim 1, wherein a control point is provided at the maximum thickness of the airfoil to ensure that L, H is greater on the pressure side of the airfoil than on the suction side.

4. The compressor blade of claim 1 wherein control points are provided at the trailing edge to ensure that H is greater than L and β is less than α.

5. The compressor blade as in claim 1, wherein a control point is provided at the leading edge to ensure L, H, α, β are minimized at the leading edge.

6. The compressor blade as claimed in claim 1, wherein the compressor blade is a stator blade or a rotor blade of a compressor.

7. A compressor comprising a plurality of compressor blades, characterized in that the compressor blades are as claimed in any one of claims 1 to 6.

8. The compressor of claim 7, wherein the compressor is a multi-stage axial compressor and the compressor blades are outlet stage blades.

9. An air compressor according to claim 7, characterized in that the air compressor is a low-flow compressor.