阅读说明：本技术 分流离心叶轮及具有其的航空发动机 (Split-flow centrifugal impeller and aircraft engine with same ) 是由 刘飞亭 胡亚飞 廖少峰 符鹏 于 2020-06-30 设计创作，主要内容包括：本发明公开了一种分流离心叶轮,包括：叶轮基体,叶轮基体的外周壁上设有多片沿其周向依次间隔布设的主叶片、布设于相邻两片主叶片之间的一级分流叶片、及布设于相邻的主叶片和一级分流叶片之间的二级分流叶片。主叶片由离心叶轮的进气端至排气端方向布设,一级分流叶片和二级分流叶片布设于离心叶轮的排气端,以减少离心叶轮进气端的叶片数量进而降低离心叶轮进气端的叶栅稠度,同时增加离心叶轮排气端的叶片数量进而提高离心叶轮排气端的叶栅稠度。本发明的分流离心叶轮中,叶栅稠度分配适宜、空气流量大、压缩比高、气流不容易分离、气动效率高。(The invention discloses a split-flow centrifugal impeller, comprising: the impeller comprises an impeller base body, wherein the peripheral wall of the impeller base body is provided with a plurality of main blades which are sequentially arranged at intervals along the circumferential direction of the impeller base body, a first-stage splitter blade arranged between two adjacent main blades and a second-stage splitter blade arranged between the adjacent main blades and the first-stage splitter blade. The main blades are arranged from the air inlet end to the air outlet end of the centrifugal impeller, and the first-stage splitter blade and the second-stage splitter blade are arranged at the air outlet end of the centrifugal impeller, so that the number of blades at the air inlet end of the centrifugal impeller is reduced, the blade grid consistency at the air inlet end of the centrifugal impeller is reduced, and the number of blades at the air outlet end of the centrifugal impeller is increased, and the blade grid consistency at the air outlet end of the centrifugal impeller is improved. In the shunting centrifugal impeller, the blade grid consistency distribution is proper, the air flow is large, the compression ratio is high, the air flow is not easy to separate, and the pneumatic efficiency is high.)

1. A split-flow centrifugal impeller, comprising:

the impeller comprises an impeller base body (10), wherein the outer peripheral wall of the impeller base body (10) is provided with a plurality of main blades (20) which are sequentially arranged at intervals along the circumferential direction of the impeller base body, a first-stage splitter blade (30) which is arranged between two adjacent main blades (20), and a second-stage splitter blade (40) which is arranged between the adjacent main blades (20) and the first-stage splitter blade (30);

the main blades (20) are arranged from the air inlet end to the air outlet end of the centrifugal impeller, the first-stage splitter blade (30) and the second-stage splitter blade (40) are arranged at the air outlet end of the centrifugal impeller, so that the number of blades at the air inlet end of the centrifugal impeller is reduced, the blade grid consistency at the air inlet end of the centrifugal impeller is reduced, and the number of blades at the air outlet end of the centrifugal impeller is increased, and the blade grid consistency at the air outlet end of the centrifugal impeller is improved.

2. The split-flow centrifugal impeller of claim 1,

the main blades (20) are uniformly distributed at intervals along the circumferential direction of the impeller base body (10), the front edges of the main blades (20) are close to the air inlet end of the impeller base body (10), and the rear edges of the main blades (20) are flush with the periphery of the air outlet end of the impeller base body (10);

the primary splitter blade (30) is positioned in the center between two adjacent main blades (20), the rear edge of the primary splitter blade (30) is flush with the periphery of the exhaust end of the impeller base body (10), and the front edge of the primary splitter blade (30) extends towards the air inlet end of the impeller base body (10);

the second-stage splitter blade (40) is located adjacent the central position between the main blade (20) and the first-stage splitter blade (30), and the trailing edge of the second-stage splitter blade (40) is flush with the periphery of the exhaust end of the impeller base body (10), and the leading edge of the second-stage splitter blade (40) extends towards the intake end of the impeller base body (10).

3. The split-flow centrifugal impeller of claim 2,

the chord length of the main blade (20) is larger than that of the first-stage splitter blade (30), and the chord length of the first-stage splitter blade (30) is larger than that of the second-stage splitter blade (40);

the number of the main blades (20) is 5-9.

4. The split-flow centrifugal impeller of claim 2,

the main blade (20), the first-stage splitter blade (30) and the second-stage splitter blade (40) are the same in blade profile;

the thickness difference among the main blade (20), the first-stage splitter blade (30) and the second-stage splitter blade (40) is 0.5-1 mm.

5. The split-flow centrifugal impeller of claim 2,

fillets with adjustable angles are respectively arranged at the joints of the blade roots of the first-stage splitter blades (30) and the outer peripheral wall of the impeller base body (10) and at the joints of the blade roots of the second-stage splitter blades (40) and the outer peripheral wall of the impeller base body (10), so that the base frequencies of the corresponding first-stage splitter blades (30) or the corresponding second-stage splitter blades (40) are adjusted by adjusting the angles of the fillets to reduce noise; and/or

The first-stage splitter blade (30) and the second-stage splitter blade (40) are adjustable blades with adjustable blade thickness, and the corresponding first-stage splitter blade (30) or the base frequency of the second-stage splitter blade (40) is adjusted through adjusting the blade thickness so as to reduce noise.

6. The split-flow centrifugal impeller of claim 1,

the end face of the air inlet end of the impeller base body (10) is provided with an inwards concave annular mounting ring cavity (101), and the mounting ring cavity (101) is used for installing the brushless motor in an interference mode.

7. The split-flow centrifugal impeller of claim 6,

the peripheral wall of impeller base member (10) be equipped with air vent (102) of installation ring chamber (101) intercommunication, air vent (102) are used for supplying the air current in the centrifugal impeller runner gets into installation ring chamber (101) is in order to cool off brushless motor.

8. The split-flow centrifugal impeller of claim 6,

a mounting cylinder is arranged in the center of the mounting ring cavity (101), and the mounting cylinder is a centering cylinder (103) used for mounting and centering the brushless motor;

the exhaust end of the impeller base body (10) is recessed to form an annular circumferential edge (104), and arc end teeth are processed on the annular circumferential edge (104) and used for being meshed with the arc end teeth on the compressor.

9. The split-flow centrifugal impeller of claim 8,

and a weight reducing cavity (105) for reducing the weight of the impeller base body (10) is further arranged in the impeller base body (10), and two ends of the weight reducing cavity (105) in the axial direction are respectively communicated with the exhaust end of the impeller base body (10) and the mounting ring cavity (101).

10. An aircraft engine comprising a split-flow centrifugal impeller according to any one of claims 1 to 9.

Technical Field

The invention relates to the field of aircraft engines, in particular to a shunting centrifugal impeller. In addition, the invention also relates to an aircraft engine comprising the shunting centrifugal impeller.

Background

The centrifugal impeller of the aviation turbine engine is improved creatively for many times, and the variety of the centrifugal impeller is more and more. Early two-sided air intake centrifugal impellers were modular and have been eliminated; the existing centrifugal impellers are single-side air inlet centrifugal impellers; the centrifugal impeller in later stage has increased splitter blade, and the high pressure ratio centrifugal impeller that uses now is the one-level splitter centrifugal impeller almost totally, and splitter blade and main blade quantity are equal, and along with the progress of motor technology, centrifugal impeller has the trend with brushless motor combination, for realizing this purpose, need do many technical scheme and test to solve many technical problem.

Advanced aero-engines in pre-research need to further improve the pressure ratio of a centrifugal compressor, improve pneumatic efficiency, reduce the weight of an impeller, and need to install an integrated brushless motor in the centrifugal impeller.

According to the stress analysis of high-speed rotation of the impeller, when a large hole is dug on the impeller and the starting integrated brushless motor is installed, the material stress is obviously increased, and the problems of the strength and the cooling of the impeller are further caused; on the other hand, to further improve the pressure ratio of the centrifugal compressor, improve the pneumatic efficiency and reduce the weight of the impeller, a plurality of technical schemes and tests are required to be performed, and a plurality of technical problems are solved.

Disclosure of Invention

The invention provides a shunting centrifugal impeller and an aeroengine with the same, and aims to solve the technical problems of low compression ratio and low pneumatic efficiency of the conventional shunting centrifugal impeller.

The technical scheme adopted by the invention is as follows:

a split-flow centrifugal impeller comprising: the impeller comprises an impeller base body, wherein the outer peripheral wall of the impeller base body is provided with a plurality of main blades sequentially distributed at intervals along the circumferential direction of the impeller base body, a first-stage splitter blade distributed between two adjacent main blades and a second-stage splitter blade distributed between the adjacent main blades and the first-stage splitter blade; the main blades are arranged from the air inlet end to the air outlet end of the centrifugal impeller, and the first-stage splitter blade and the second-stage splitter blade are arranged at the air outlet end of the centrifugal impeller, so that the number of blades at the air inlet end of the centrifugal impeller is reduced, the blade grid consistency at the air inlet end of the centrifugal impeller is reduced, and the number of blades at the air outlet end of the centrifugal impeller is increased, and the blade grid consistency at the air outlet end of the centrifugal impeller is improved.

Furthermore, a plurality of main blades are uniformly distributed at intervals along the circumferential direction of the impeller base body, the front edges of the main blades are close to the air inlet end of the impeller base body, and the rear edges of the main blades are flush with the periphery of the exhaust end of the impeller base body; the first-stage splitter blade is positioned in the center between two adjacent main blades, the rear edge of the first-stage splitter blade is flush with the periphery of the exhaust end of the impeller base body, and the front edge of the first-stage splitter blade extends towards the air inlet end of the impeller base body; the second-stage splitter blade is positioned in the center between the adjacent main blade and the first-stage splitter blade, the rear edge of the second-stage splitter blade is flush with the periphery of the exhaust end of the impeller base body, and the front edge of the second-stage splitter blade extends towards the air inlet end of the impeller base body.

Furthermore, the chord length of the main blade is larger than that of the first-stage splitter blade, and the chord length of the first-stage splitter blade is larger than that of the second-stage splitter blade; the number of the main blades is 5-9.

Furthermore, the main blade, the first-stage splitter blade and the second-stage splitter blade are the same in blade profile; the thickness difference of the main blade, the first-stage splitter blade and the second-stage splitter blade is 0.5-1 mm.

Furthermore, fillets with adjustable angles are respectively arranged at the joints of the blade roots of the first-stage splitter blades and the outer peripheral wall of the impeller base body and at the joints of the blade roots of the second-stage splitter blades and the outer peripheral wall of the impeller base body, so that the base frequencies of the corresponding first-stage splitter blades or second-stage splitter blades are adjusted by adjusting the angles of the fillets to reduce noise; and/or the first-stage splitter blade and the second-stage splitter blade are adjustable blades with adjustable blade thicknesses, so that the base frequency of the corresponding first-stage splitter blade or second-stage splitter blade is adjusted by adjusting the blade thicknesses to reduce noise.

Furthermore, the end face of the air inlet end of the impeller base body is provided with an inwards-concave annular mounting ring cavity, and the mounting ring cavity is used for installing the brushless motor in an interference mode.

Furthermore, the peripheral wall of the impeller base body is provided with a vent hole communicated with the mounting ring cavity, and the vent hole is used for allowing air flow in the centrifugal impeller flow channel to enter the mounting ring cavity so as to cool the brushless motor.

Furthermore, a mounting cylinder is arranged in the center of the mounting ring cavity, and the mounting cylinder is a centering cylinder for mounting and centering the brushless motor; the exhaust end of the impeller base body is recessed to form an annular circumferential edge, and arc end teeth are processed on the annular circumferential edge and used for being meshed with the arc end teeth on the air compressor.

Furthermore, a weight reduction cavity for reducing the weight of the impeller base body is further arranged in the impeller base body, and two ends of the weight reduction cavity along the axial direction are respectively communicated with the exhaust end of the impeller base body and the mounting ring cavity.

According to a further aspect of the present invention there is also provided an aircraft engine comprising a splitter centrifugal impeller according to any one of the preceding claims.

The invention has the following beneficial effects:

in the shunting centrifugal impeller, the main blades are arranged from the air inlet end to the air outlet end of the centrifugal impeller, and the first-stage shunting blades and the second-stage shunting blades are uniformly distributed at the air outlet end of the centrifugal impeller. When the number of the blades at the air inlet end of the centrifugal impeller is reduced, the sectional area of the airflow channel is increased, which is beneficial to increasing the airflow and reducing the blade grid consistency at the air inlet end of the centrifugal impeller; when the number of blades at the exhaust end of the centrifugal impeller is increased, the blade grid consistency at the exhaust end of the centrifugal impeller is large, the sectional area of an airflow channel is narrow, and the airflow is more easily attached to a blade basin or a blade back of the blade when flowing, so that the airflow is not easy to separate, the pneumatic efficiency of the centrifugal impeller is high, and meanwhile, because the diameter of the exhaust end of the centrifugal impeller is about four times of the diameter of a hub at the air inlet end of the centrifugal impeller, the circumferential linear speed of the exhaust end of the centrifugal impeller is high, and the number of blades at the exhaust end is large, the exhaust end has strong work-doing capability and high compression ratio, so in the shunting centrifugal impeller, the blade grid consistency distribution is proper, the air flow is large;

the aero-engine provided by the invention has the advantages of proper blade grid consistency distribution, large air flow, high compression ratio, difficulty in air flow separation and high pneumatic efficiency.

In addition to the objects, features and advantages described above, other objects, features and advantages of the present invention are also provided. The present invention will be described in further detail below with reference to the drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic spatial structure of a split-flow centrifugal impeller according to a preferred embodiment of the present invention;

FIG. 2 is a schematic cross-sectional front view of the structure of FIG. 1;

fig. 3 is a schematic view of a portion of the structure of an aircraft engine in accordance with a preferred embodiment of the present invention.

Description of the figures

10. An impeller base body; 101. installing a ring cavity; 102. a vent hole; 103. a centering cylinder; 104. an annular periphery; 105. a weight-reducing cavity; 20. a main blade; 30. a first stage splitter blade; 40. and a secondary splitter blade.

Detailed Description

The embodiments of the invention will be described in detail below with reference to the accompanying drawings, but the invention can be embodied in many different forms, which are defined and covered by the following description.

Referring to fig. 1, a preferred embodiment of the present invention provides a split-flow centrifugal impeller comprising: the impeller comprises an impeller base body 10, wherein the peripheral wall of the impeller base body 10 is provided with a plurality of main blades 20 sequentially arranged at intervals along the circumferential direction, a first-stage splitter blade 30 arranged between two adjacent main blades 20, and a second-stage splitter blade 40 arranged between the adjacent main blades 20 and the first-stage splitter blade 30. The main blades 20 are arranged from the air inlet end to the air outlet end of the centrifugal impeller, and the first-stage splitter blade 30 and the second-stage splitter blade 40 are arranged at the air outlet end of the centrifugal impeller, so that the blade number of the air inlet end of the centrifugal impeller is reduced, the blade grid consistency of the air inlet end of the centrifugal impeller is reduced, and the blade number of the air outlet end of the centrifugal impeller is increased, and the blade grid consistency of the air outlet end of the centrifugal impeller is improved.

In the shunting centrifugal impeller of the invention, because the main blades 20 are arranged from the air inlet end to the air outlet end of the centrifugal impeller, and the first-stage shunting blades 30 and the second-stage shunting blades 40 are uniformly distributed at the air outlet end of the centrifugal impeller, the arrangement mode is equivalent to the reduction of the number of the blades at the air inlet end of the centrifugal impeller and the increase of the number of the blades at the air outlet end of the centrifugal impeller. When the number of the blades at the air inlet end of the centrifugal impeller is reduced, the sectional area of the airflow channel is increased, which is beneficial to increasing the airflow and reducing the blade grid consistency at the air inlet end of the centrifugal impeller; when the number of blades at the exhaust end of the centrifugal impeller is increased, the blade grid consistency at the exhaust end of the centrifugal impeller is large, the sectional area of an airflow channel is narrow, and the blade basin or the blade back of the blade is more easily attached to the airflow when the airflow flows, so that the airflow is not easy to separate, the pneumatic efficiency of the centrifugal impeller is high, and meanwhile, because the diameter of the exhaust end of the centrifugal impeller is about four times of the diameter of a hub at the air inlet end of the centrifugal impeller, the circumferential linear speed of the exhaust end of the centrifugal impeller is high, and the number of blades at the exhaust end is large, the work capacity of the exhaust end is high, and the compression ratio is high, so in the shunting centrifugal impeller, the blade grid consistency distribution is proper, the.

Alternatively, as shown in fig. 1, a plurality of main blades 20 are uniformly spaced along the circumferential direction of the impeller base 10, the leading edges of the main blades 20 are close to the air inlet end of the impeller base 10, and the trailing edges of the main blades 20 are flush with the periphery of the air outlet end of the impeller base 10. The first-stage splitter blade 30 is located at the center between two adjacent main blades 20, the rear edge of the first-stage splitter blade 30 is flush with the periphery of the exhaust end of the impeller base body 10, and the front edge of the first-stage splitter blade 30 extends towards the intake end of the impeller base body 10. Since the plurality of main blades 20 are uniformly arranged at intervals along the circumferential direction of the impeller base body 10, and the first-stage splitter blade 30 is located at the center of the two adjacent main blades 20, the plurality of first-stage splitter blades 30 are also uniformly arranged at intervals along the circumferential direction of the impeller base body 10. The second-stage splitter blade 40 is located at the center between the adjacent main blades 20 and the first-stage splitter blade 30, the rear edge of the second-stage splitter blade 40 is flush with the periphery of the exhaust end of the wheel base 10, and the front edge of the second-stage splitter blade 40 extends toward the intake end of the wheel base 10.

In this alternative, as shown in fig. 1, the chord length of the main blade 20 is greater than that of the first-stage splitter blade 30, and the chord length of the first-stage splitter blade 30 is greater than that of the second-stage splitter blade 40. The number of the blades at the exhaust end of the centrifugal blade is increased, the average power of a single blade is reduced, and when the chord length of the main blade 20 is larger than that of the first-stage splitter blade 30 and the chord length of the first-stage splitter blade 30 is larger than that of the second-stage splitter blade 40, the total weight of the blades can be reduced, which is beneficial to reducing the total weight of the centrifugal impeller. The number of the main blades 20 is 5 to 9. In the existing design, the number of the main blades in the first-stage shunting centrifugal impeller is generally 11, or even more, and in the second-stage shunting centrifugal impeller of the invention, the number of the main blades 20 is 5-9, compared with the first-stage shunting centrifugal impeller, the number of the blades at the air inlet end of the second-stage shunting centrifugal impeller is reduced, thereby reducing the centrifugal load at the air inlet end of the centrifugal impeller and facilitating the related design of the air inlet end structure of the subsequent centrifugal impeller.

In this alternative, as shown in fig. 1, the main blades 20, the first-stage splitter blades 30, and the second-stage splitter blades 40 have the same blade profile, which is beneficial to improving the structural uniformity of the centrifugal impeller and reducing the vibration caused by the non-uniform structure in the rotation process of the centrifugal impeller. The blade thickness difference of the main blade 20, the first-stage splitter blade 30 and the second-stage splitter blade 40 is 0.5 mm-1 mm, the structural uniformity of the centrifugal impeller is further improved, and vibration caused by uneven structure in the rotating process of the centrifugal impeller is further reduced.

Optionally, as shown in fig. 1, a joint between a blade root of the first-stage splitter blade 30 and the outer peripheral wall of the impeller base 10 and a joint between a blade root of the second-stage splitter blade 40 and the outer peripheral wall of the impeller base 10 respectively have fillets with adjustable angles, so as to adjust the fundamental frequency of the corresponding first-stage splitter blade 30 or second-stage splitter blade 40 by adjusting the angles of the fillets to reduce noise. And/or the first-stage splitter blade 30 and the second-stage splitter blade 40 are adjustable blades with adjustable blade thicknesses, so that the base frequency of the corresponding first-stage splitter blade 30 or second-stage splitter blade 40 is adjusted by adjusting the blade thicknesses to reduce noise. Because the first-stage splitter blade 30 and the second-stage splitter blade 40 can be regarded as the truncated main blade 20, the weight of the centrifugal impeller is light, and the fundamental frequency is higher.

Optionally, as shown in fig. 1 and fig. 2, an end surface of the air inlet end of the impeller base body 10 is provided with a concave and annular mounting ring cavity 101, and the mounting ring cavity 101 is used for interference mounting of the brushless motor. After the concave mounting ring cavity 101 for mounting the brushless motor is processed at the air inlet end of the impeller base body 10, the strength of the air inlet end of the impeller base body 10 is weakened. In the structure of the invention, the brushless motor integrating starting and power generation is arranged at the air inlet end of the centrifugal impeller, so that the design requirement of a new generation of multi-electric aircraft engine is met, various accessories can be driven by electric power due to sufficient electric power, and compared with the existing aircraft engine, the brushless motor is driven by an additional accessory gear transmission mechanism. In the alternative, the assembly interference between the mounting ring cavity 101 and the outer rotor of the brushless motor reaches 0.05 mm-0.1 mm.

Preferably, as shown in fig. 1 and 2, the outer peripheral wall of the impeller base 10 is provided with a vent hole 102 communicated with the mounting ring cavity 101, and the vent hole 102 is used for allowing the airflow in the centrifugal impeller flow passage to enter the mounting ring cavity 101 to cool the brushless motor. In the embodiment of the preferred embodiment, the number of the vent holes 102 is multiple, the vent holes 102 are uniformly distributed at intervals along the circumferential direction of the impeller base body 10, and each vent hole 102 is obliquely distributed along the airflow flowing direction, so that the airflow in the flow channel can smoothly enter the mounting ring cavity 101 through the vent hole 102.

Alternatively, as shown in fig. 1 and 2, the mounting ring cavity 101 is centrally provided with a mounting cylinder, which is a centering cylinder 103 for mounting and centering the brushless motor. In this alternative, the outer cylindrical surface of the centering cylinder 103 is a centering cylindrical surface for mounting and centering the brushless motor. The exhaust end of the impeller base body 10 is recessed to form an annular circumferential edge 104, and arc-shaped end teeth are processed on the annular circumferential edge 104 and are used for being meshed with the arc-shaped end teeth on the compressor.

Optionally, as shown in fig. 2, a weight-reducing cavity 105 for reducing the weight of the impeller base body 10 is further provided in the impeller base body 10, and two ends of the weight-reducing cavity 105 in the axial direction are respectively communicated with the exhaust end of the impeller base body 10 and the mounting ring cavity 101.

Referring to fig. 3, a preferred embodiment of the present invention provides an aircraft engine comprising a splitter centrifugal impeller as described in any one of the above. Because the aero-engine comprises the shunting centrifugal impeller in any one of the above manners, the aero-engine has the advantages of proper blade cascade consistency distribution, large air flow, high compression ratio, difficult separation of air flow and high aerodynamic efficiency.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.