CN110005640B

CN110005640B - Fan blade, compressor and aircraft engine

Info

Publication number: CN110005640B
Application number: CN201810007222.4A
Authority: CN
Inventors: 戴磊; 羌晓青
Original assignee: AECC Commercial Aircraft Engine Co Ltd
Current assignee: AECC Commercial Aircraft Engine Co Ltd
Priority date: 2018-01-04
Filing date: 2018-01-04
Publication date: 2020-07-03
Anticipated expiration: 2038-01-04
Also published as: CN110005640A

Abstract

The invention relates to a fan blade, an air compressor and an aero-engine, wherein the fan blade comprises a blade body (1), the blade body (1) is made of a non-metal material or a material formed by mixing metal and non-metal, the outer surface of the front edge of the blade body (1) is wrapped with a memory alloy wrapping edge (2), and the memory alloy wrapping edge (2) can deform so as to change the geometric inlet angle of the front edge of the fan blade. In the embodiment of the fan blade, the memory alloy wrapping edge is wrapped on the outer surface of the front edge of the blade body made of non-metal materials or metal and non-metal mixed materials, and the geometric inlet angle of the front edge of the fan blade can be changed through the deformation of the memory alloy wrapping edge, so that the attack angle of airflow entering a cascade channel is changed, airflow separation is reduced as far as possible, the aerodynamic loss is reduced, and the performance of an air compressor is improved.

Description

Fan blade, compressor and aircraft engine

Technical Field

The invention relates to the technical field of aero-engines, in particular to a fan blade, a compressor and an aero-engine.

Background

The compressor is required to have the characteristics of high pressure ratio and high efficiency in modern aero-engine design, each stage of the compressor is composed of movable blades and static blades, the compressor mainly has the function of compressing air through the movable blades rotating at high speed to do work, so that the air obtains kinetic energy and pressure energy, the compressed air enters the static blade channel to further convert the obtained kinetic energy into the pressure energy and flows into the movable blades of the next stage at a proper angle, and therefore the high pressure ratio can be finally obtained in a mode of increasing the air pressure step by step. However, the improvement of the pressure ratio is accompanied with the increase of the aerodynamic load of the compressor blades, and meanwhile, the loss of the compressor is correspondingly increased, if the loss is not controlled, the performance of the compressor is greatly reduced, and even serious consequences are caused.

When the compressor works under the designed working condition, air enters each row of blades at a proper angle to complete the pressurization process, the attack angle is small, and the total pressure loss is small from the view of the attack angle characteristic. However, when the compressor works under the working condition of a non-design point, the flow of the compressor is reduced, the attack angle of airflow entering the blade cascade channel is increased, and after the attack angle is increased to a certain degree, the airflow is separated at the blade back, so that the loss is greatly increased, and the performance of the compressor is obviously reduced.

At present, the performance of a blade is improved and the loss is reduced mainly by a method of optimally designing the blade of a gas compressor, for example, Chinese patent document CN106021681A, the publication date is 2016, 10, month and 12, and discloses a method and a device for optimizing the blade profile of the gas compressor. However, this only reduces the loss caused by the increase of the attack angle slightly compared with the original design, and does not fundamentally solve the problem of the separation of the airflow at the blade back under the large attack angle. As the angle of attack is further increased, the tendency for the corresponding overall pressure loss to increase more rapidly is not addressed.

It is noted that the information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information constitutes prior art already known to a person skilled in the art.

Disclosure of Invention

The invention aims to provide a fan blade, a gas compressor and an aero-engine, and aims to solve the problems that the air flow attack angle is increased and the aerodynamic loss is increased under the non-design working condition of the fan blade in the prior art.

In order to achieve the purpose, the invention provides a fan blade which comprises a blade body, wherein the blade body is made of a non-metal material or a material formed by mixing metal and non-metal, the outer surface of the front edge of the blade body is wrapped with a memory alloy wrapping edge, and the memory alloy wrapping edge can deform so as to change the geometric inlet angle of the front edge of the fan blade.

Further, on the airfoil surface, the memory alloy rim extends a greater length over the pressure side of the leading edge than over the suction side of the leading edge.

Further, the thickness distribution of the memory alloy wrapping edge is configured to enable the outer contour of the fan blade wrapped with the memory alloy wrapping edge to meet the pneumatic requirement.

Further, the memory alloy wrapping edge extends to the blade root along the blade tip of the blade body.

In order to achieve the purpose, the invention further provides a compressor which comprises the fan blade.

Further, the compressor also comprises a temperature adjusting device, and the temperature adjusting device is used for adjusting the temperature of the memory alloy wrapping edge on the blade body of the fan blade.

Further, the temperature adjustment means is provided inside or on the outer surface of the blade body.

In order to achieve the purpose, the invention further provides an aircraft engine which comprises the compressor.

Further, the aircraft engine also comprises a control switch for controlling the temperature adjusting device in the compressor to be turned on or off.

Furthermore, the aircraft engine also comprises a detection device, the detection device is used for detecting the pressure or the flow of the front edge of the fan blade in the air compressor, and the detection device is in signal connection with the control switch, so that the control switch can control the temperature adjusting device to be turned on or turned off according to the pressure signal or the flow signal detected by the detection device.

Based on the technical scheme, in the embodiment of the fan blade, the memory alloy wrapping edge is wrapped on the outer surface of the front edge of the blade body made of the non-metal material or the metal and non-metal mixed material, and the geometric inlet angle of the front edge of the fan blade can be changed through the deformation of the memory alloy wrapping edge, so that the attack angle of airflow entering a cascade channel is changed, airflow separation is reduced as far as possible, aerodynamic loss is reduced, and the performance of an air compressor is improved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention. In the drawings:

FIG. 1 is a schematic view of a flow separation of a conventional prior art vane at a non-zero angle of attack.

FIG. 2 is a characteristic diagram of angle of attack loss of a blade under different Mach numbers of a common blade in the prior art.

FIG. 3 is a schematic structural view of one embodiment of a fan blade of the present invention

FIG. 4 is a schematic structural view of an embodiment of a fan blade of the present invention before and after deformation.

In the figure:

1. a blade body; 2. and (5) wrapping the memory alloy.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments. It is to be understood that the described embodiments are merely a few embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "central," "lateral," "longitudinal," "front," "rear," "left," "right," "upper," "lower," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in the orientation or positional relationship indicated in the drawings for convenience in describing the invention and for simplicity in description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the scope of the invention.

To achieve the purpose of the invention, the invention provides a fan blade with an improved structure.

As shown in fig. 3, in an exemplary embodiment of a fan blade provided by the present invention, the fan blade includes a blade body 1, the blade body 1 is made of a non-metal material or a material of a mixture of a metal and a non-metal material, an outer surface of a leading edge of the blade body 1 is wrapped with a memory alloy covered edge 2, and the memory alloy covered edge 2 can be deformed to change a geometric inlet angle of the leading edge of the fan blade.

The geometric inlet angle refers to an included angle between the tangent of a camber line of a fan blade profile at the vertex of the leading edge and the frontal line of a blade cascade, and the frontal line of the blade cascade refers to a straight line connecting the vertexes of the leading edges of all the blades. The angle of attack is the angle between the airflow inlet angle and the geometric inlet angle, and the airflow inlet angle is the angle between the airflow incoming direction and the frontal line of the blade cascade. Therefore, after the incoming flow direction of the airflow is changed, the geometric inlet angle of the front edge is changed, and the attack angle can be changed.

In the above exemplary embodiment, the improved object is a blade body 1 made of a non-metal material or a mixed material of a metal and a non-metal material, the outer surface of the front edge of the blade body 1 is wrapped with a memory alloy wrapping edge 2, and the geometric inlet angle of the front edge of the fan blade can be changed through the deformation of the memory alloy wrapping edge 2, so that the attack angle of airflow entering the cascade channel is changed, airflow separation is reduced as much as possible, aerodynamic loss is reduced, and the performance of the compressor is improved.

In addition, compared with the scheme that the whole blade is made of the memory alloy material, the scheme that the memory alloy wrapping edge 2 is wrapped on the outer surface of the front edge has more advantages, such as the local control of the front edge can be realized, and the control characteristic is improved; the technical support is provided for the deformation of the non-metal blade or the metal and nonmetal mixed blade, and the strength of the non-metal blade or the metal and nonmetal mixed blade can be improved; is favorable for saving materials, reducing cost and the like.

The memory alloy edge cover 2 is made of Shape Memory Alloy (SMA), the shape memory alloy has shape memory effect, deformation (low temperature phase) at low temperature can be eliminated after heating, and the original shape (high temperature phase) before deformation is recovered. Optionally, a memory alloy material with a two-way memory effect is adopted, the high-temperature phase shape can be recovered during heating, and the low-temperature phase shape can be recovered during cooling, so that the memory alloy wrapping edge 2 can be switched between at least two shapes to meet the requirements of different incoming flow directions, the front edge attack angle of the fan blade can achieve the purposes of smaller attack angle and smaller aerodynamic loss no matter what working condition, and the overall performance of the compressor is improved.

Further, on the airfoil surface, the memory alloy rim 2 extends over a greater length on the pressure side of the leading edge than on the suction side of the leading edge. The arrangement can better protect the leading edge pressure surface of the fan blade and enhance the shock resistance of the pressure surface.

Optionally, the thickness distribution of the memory alloy covered edge 2 is configured to enable the outer contour of the fan blade after the memory alloy covered edge 2 is wrapped to meet the aerodynamic requirement. The arrangement can avoid the change of the integral blade profile of the fan blade due to the wrapping of the memory alloy wrapping edge 2, and avoid the increase of pneumatic loss caused by the change of the blade profile.

Optionally, the memory alloy covered edge 2 extends to the blade root along the blade tip of the blade body 1, namely the memory alloy covered edge 2 covers the whole radial length of the blade body 1, so that the whole deformation of the front edge of the fan blade can be realized, the deformation capacity is improved, and the adjustment of the attack angle is more convenient, accurate and reliable.

Based on the fan blades in the various embodiments, the invention further provides a compressor, and the compressor comprises the fan blades.

Further, the compressor also comprises a temperature adjusting device, and the temperature adjusting device is used for adjusting the temperature of the memory alloy wrapping edge 2 on the blade body 1 of the fan blade. Through setting up temperature regulation apparatus, can adjust the temperature of memory alloy bordure 2 in real time to make memory alloy bordure 2 can take place corresponding deformation, reach the purpose that reduces geometric inlet angle and angle of attack.

The specific structural form of the temperature adjusting device is not limited as long as the memory alloy wrapping edge 2 can be heated or cooled.

Optionally, the temperature regulating means is provided inside or on the outer surface of the blade body 1. The temperature adjusting device is arranged in the blade body 1, so that the temperature adjusting device can be prevented from interfering with other parts outside the blade body 1, and the temperature adjusting device is protected; for temperature adjusting devices in the form of resistance wires and the like, the temperature adjusting devices can also be arranged on the outer surface of the blade body 1 for convenient operation.

Based on the compressor in each embodiment, the invention further provides an aircraft engine which comprises the compressor.

Further, the aircraft engine also comprises a control switch for controlling the temperature adjusting device in the compressor to be turned on or off. Through setting up control switch, can conveniently control temperature regulation apparatus's the opening and close. The specific structural form of the control switch is not limited as long as the function thereof can be achieved.

Optionally, the aircraft engine further comprises a detection device for detecting the pressure or flow of the leading edge of the fan blade in the compressor, and the detection device is in signal connection with the control switch, so that the control switch can control the temperature regulation device to be turned on or turned off according to the pressure signal or the flow signal detected by the detection device. Through setting up detection device, can provide judgement standard and basis for temperature regulation device's on-off control, improve the accuracy of control.

The working process of one embodiment of the fan blade, the compressor and the aircraft engine of the invention is described below with reference to the accompanying drawings 1-3:

as shown in FIG. 1, under design conditions, a zero angle of attack condition is typical. As shown in FIG. 2, in the range of small negative attack angle and positive attack angle, the total pressure loss of the blade profile is at a lower level; however, at large positive angles of attack, separation of the airflow at the blade back occurs, resulting in a dramatic increase in losses. When the flow of the compressor is reduced, the attack angle is increased, and although the total pressure loss can be reduced to a certain extent by a traditional mode of optimizing the blade profile type line, the trend that the total pressure loss is increased sharply due to the increase of the attack angle cannot be changed.

As shown in fig. 3, a fan blade of a compressor comprises a blade body 1, wherein a memory alloy wrapping edge 2 is wrapped on the outer surface of the front edge of the blade body 1, and the memory alloy wrapping edge is wrapped on the front edge of the blade body 1 from the front edge point. Specifically, the memory alloy wrapping 2 comprises a front edge wrapping, a pressure surface wrapping and a suction surface wrapping, the front edge wrapping is wrapped at the front end of the front edge of the blade body 1, the pressure surface wrapping is wrapped at the front edge pressure side of the blade body 1, and the suction surface wrapping is wrapped at the front edge suction side of the blade body 1. Optionally, the leading edge strip, the pressure surface strip and the suction surface strip are integrally formed. The shape of the front edge wrapping edge is basically the same as that of the original blade profile of the blade body 1, the thickness of the pressure surface wrapping edge is gradually reduced along the direction from the front edge to the tail edge, and the thickness of the suction surface wrapping edge is also gradually reduced along the direction from the front edge to the tail edge, so that the blade profile of the fan blade wrapped by the memory alloy wrapping edge 2 still meets the pneumatic requirement, and the pneumatic loss possibly brought by the change of the blade profile is reduced.

The temperature adjusting device is arranged in the blade body 1, the temperature adjusting device is controlled to be opened or closed by the control switch, the detecting device can detect the pressure or flow of the front edge of the fan blade, and when the pressure or flow of the front edge reaches a preset value, the control switch is triggered to start the temperature adjusting device.

As shown in fig. 4, before the preset value is reached, the memory alloy edge 2 of the front edge keeps a low-temperature phase, which is an a-type front edge, so that the blade runs at a design point state of small attack angle and loss resistance; when the flow changes to increase the attack angle, the pressure of the front edge of the blade profile changes to trigger the control switch, the temperature adjusting device is started, the memory alloy wrapping edge 2 can be heated, the temperature rises, the memory alloy wrapping edge 2' is formed after the memory alloy wrapping edge 2 deforms and becomes a high-temperature phase which is a B-shaped front edge, and at the moment, the geometric air inlet angle of the blade changes, so that the incoming flow attack angle is reduced. When the flow and the running state are recovered to the working condition of the design point, the heating of the temperature adjusting device to the memory alloy wrapping edge 2 can be stopped, and the blade profile is recovered to the original shape.

Through the description of the fan blade, the air compressor and the aero-engine, the memory alloy wrapping edges are arranged, so that the shape of the memory alloy wrapping edges can be changed when the temperature is changed, the shape of the front edge of the blade profile is changed, the geometric inlet angle of the blade profile of the fan blade is changed, the attack angle is reduced, and the fan blade, the air compressor and the aero-engine can have the attack angle loss characteristic similar to that of a design working condition under the non-design working condition; and when the flow of the compressor is recovered to the flow of the designed working condition, the shape of the blade profile can be recovered. Therefore, under the two states of a small-flow working condition and a design working condition, the shape of the front edge of the blade is changed and restored, so that the airflow always runs in the characteristic range of low attack angle loss, the flow separation at the blade back is avoided, and the stable and efficient running of the compressor is ensured.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention and not to limit it; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art will understand that: modifications to the specific embodiments of the invention or equivalent substitutions for parts of the technical features may be made; without departing from the spirit of the present invention, it is intended to cover all aspects of the invention as defined by the appended claims.

Claims

1. A fan blade is characterized by comprising a blade body (1), wherein the blade body (1) is made of a non-metal material or a material formed by mixing metal and non-metal, the outer surface of the front edge of the blade body (1) is wrapped with a memory alloy wrapping edge (2), and the memory alloy wrapping edge (2) can deform so as to change the geometric inlet angle of the front edge of the fan blade; the memory alloy edge-covering (2) extends to the blade root along the blade tip of the blade body (1).

2. A fan blade according to claim 1, characterized in that the memory alloy tipping (2) extends over a greater length on the pressure side of the leading edge than on the suction side of the leading edge on the profile surface.

3. The fan blade of claim 1, characterized in that the thickness distribution of the memory alloy tipping (2) is configured to enable the outer profile of the fan blade after wrapping the memory alloy tipping (2) to meet aerodynamic requirements.

4. A compressor comprising a fan blade as claimed in any one of claims 1 to 3.

5. The compressor of claim 4, further comprising a temperature adjusting device for adjusting the temperature of the memory alloy coating (2) on the blade body (1) of the fan blade.

6. An air compressor according to claim 5, characterised in that the temperature regulation means are arranged inside or on the outer surface of the blade body (1).

7. An aircraft engine, characterized in that it comprises a compressor as claimed in any one of claims 4 to 6.

8. The aircraft engine of claim 7, further comprising a control switch for controlling the temperature adjustment device in the compressor to turn on or off.

9. The aircraft engine of claim 8, further comprising a sensing device for sensing pressure or flow at a leading edge of a fan blade in the compressor, the sensing device being in signal communication with the control switch to enable the control switch to control the thermostat to open or close based on the pressure or flow signal sensed by the sensing device.