A new hybrid vortex reduction system for a compressor

Abstract

The application provides a new compound vortex reduction system for a compressor, relates to the vortex reduction technology field of the compressor bleed section of an aero-engine secondary air system, and is characterized in that curved fins are arranged upstream of the front stage disc of the compressor to suppress the tangential movement of the airflow upstream of the cavity, destroy the development of high-speed vortex, and guide the airflow to smoothly enter the vortex reduction pipe, so that the pressure loss in the cavity is reduced. The new compound vortex reduction system comprises a front stage compressor disc, a rear stage compressor disc, and an annular chuck and a drum fixedly connected between the two; a plurality of corresponding curved fins and curved vortex reduction pipes are arranged in the internal cavity; the curved fin comprises an integrated inlet straight section and an outlet curved section from outside to inside; and the curved vortex reduction pipe comprises an integrated curved inlet pipe and a straight section outlet pipe from outside to inside. The curved fin and the curved vortex reduction pipe are combined, and the total pressure loss coefficient can be reduced by 40%-64%.

Description

Technical Field

[0001] This invention relates to the field of vortex reduction technology in the compressor bleed air section of the secondary air system of an aero-engine, and particularly to a novel composite vortex reduction system for aero-engines. Background Technology

[0002] In modern aero engines, cooling air is drawn from the compressor and used to cool hot-end components via a secondary air system. This cooling air also seals the gap between the rotor and stator, and balances axial loads. Overall, these objectives influence the design of the engine's cold and hot ends. Since the air drawn from the compressor accounts for approximately 20% of the core airflow, this can result in a 5% loss of usable energy from the fuel, thus affecting engine thrust. Therefore, to minimize bleed air volume without compromising turbine component lifespan, improving cold air quality and reducing pressure loss are priority considerations in the design of the compressor's secondary air system.

[0003] Currently, most aero-engines employ a method of radially introducing cooling airflow into the compressor drum between the compressor discs and then axially guiding it out to cool hot-end components. During this radial inward flow, due to the Coriolis effect of the rotating compressor discs, the airflow entering the drum orifice generates a large-scale free vortex structure, resulting in significant pressure loss. The most effective solution is to incorporate a vortex suppressor into the disc cavity. A well-designed vortex suppressor structure can suppress the development of high-speed vortices within the disc cavity, thus reducing drag.

[0004] Currently, traditional vortex reducers are often combined in aero-engines to achieve higher drag reduction. For example, CN110173470A discloses a composite vortex reducer air bleed system that combines a basic tubular vortex reducer with a basic finned vortex reducer. By using a composite installation of straight pipes, straight fins, or baffles, it effectively alleviates the vibration problem during the operation of a single tubular vortex reducer, thereby reducing pressure loss during air bleed. However, this composite vortex reducer does not fully consider the flow field characteristics within the disk cavity; flow separation still occurs at the fin outlet and the vortex reducer inlet, resulting in significant pressure loss. Summary of the Invention

[0005] To address the above problems, this invention proposes a novel composite vortex suppression system for compressors. By installing curved fins upstream of the compressor's front stage disk, the tangential motion of the airflow upstream of the cavity is suppressed, disrupting the development of high-speed vortices. Simultaneously, the airflow is guided smoothly into the vortex suppressor tube, thereby reducing pressure loss within the cavity. The curved inlet design of the vortex suppressor tube effectively improves the flow separation phenomenon at the tube inlet, thus reducing pressure loss when the fluid enters the tube.

[0006] The technical solution of the present invention is as follows: The novel composite vortex reduction system is uniformly arranged in the radial inward flow process of the compressor of the secondary air system of the aero-engine. The novel composite vortex reduction system includes a front-stage compressor disk 1, a rear-stage compressor disk 2, and an annular chuck 5 and a drum 6 fixedly connected between the two. The drum 6 is located outside the annular chuck 5, and a plurality of drum holes 61 are uniformly opened on the drum 6. Each drum hole is used to introduce air. The front-stage compressor disk 1, the rear-stage compressor disk 2, the annular chuck 5 and the drum 6 are coaxial, and an internal cavity is formed between the front-stage compressor disk 1, the rear-stage compressor disk 2 and the drum 6.

[0007] The internal cavity is also provided with a number of one-to-one corresponding curved fins 3 and curved vortex-reducing tubes 4, wherein the curved fins 3 are located between the drum hole 61 and the curved vortex-reducing tubes 4.

[0008] The curved fins 3 are fixedly connected to the surface of the front stage compressor disk 1 and are evenly arranged along its circumference. Each curved fin has the same structure and the same installation radius. The curved fins 3 include an integral inlet straight section 31 and an outlet curved section 32 from the outside to the inside. The outlet curved section 32 is set towards the curved de-vortex tube 4 to suppress the tangential motion of the airflow upstream of the cavity, destroy the development of high-speed vortex, and guide the airflow smoothly into the de-vortex tube to reduce the pressure loss in the disk cavity.

[0009] The curved vortex reducer 4 is connected and fixedly mounted on the annular chuck 5. The curved vortex reducers 4 are evenly arranged around the circumference of the annular chuck 5. Each curved vortex reducer has the same structure and the same installation radius. The curved vortex reducer 4 includes a curved inlet pipe 41 and a straight outlet pipe 42 that are connected as a single unit from the outside to the inside. The straight outlet pipe 42 is connected and fixedly mounted on the annular chuck 5. The curved inlet pipe 41 faces the incoming flow direction and guides the airflow into the pipe to reduce local losses at the inlet of the vortex reducer and reduce the generation of rigid vortex structures inside the vortex reducer to reduce pressure loss.

[0010] Under normal operating conditions, the plurality of curved fins and the plurality of curved anti-vortex tubes rotate in the same direction, at the same speed, and coaxially with the compressor discs on both sides. The airflow enters the compressor cavity through the plurality of drum holes and is finally introduced radially into the compressor axial channel through the plurality of curved fins and the plurality of curved anti-vortex tubes.

[0011] Furthermore, the outlet curved section 32 is connected to the curved inlet pipe 41, and the center lines of both are arc-shaped.

[0012] Furthermore, all the inlet straight sections 31 are located on the same circumference, and the angle α between the inlet straight section 31 and the tangent of the circumference at the inlet straight section 31 is 20° to 90°.

[0013] Furthermore, the angle β between the inlet plane of the curved inlet pipe 41 and the tangent of the circumference where the center point of the inlet of the curved inlet pipe 41 is located is 90°.

[0014] Furthermore, the axis of the curved fin outlet curved section 32 forms an angle γ of 90° with the inlet plane of the curved inlet pipe 41.

[0015] Furthermore, the cross-sectional area of ​​the inner wall of the curved vortex reducer 4 is consistent at all points.

[0016] The curved vortex reducers have the same installation radius on the annular chuck, and the circles containing each curved vortex reducer are coaxially arranged with the annular chuck.

[0017] Each drum hole is configured to improve the flow capacity of gas at the drum hole.

[0018] Each drum bore has an oblong cross-section.

[0019] The curved fin inlet is located at a swirl ratio close to 1.

[0020] The outlet axis of each curved fin and the inlet center axis of the curved vortex tube are generated by spline curves.

[0021] The present invention discloses a novel composite anti-vortex system for compressors. The system includes an annular chuck, several curved fins, and several curved anti-vortex tubes. The curved fins are installed at the high radius of the compressor disk in the front stage of the compressor and are evenly placed circumferentially. The curved fins have a straight inlet section and a curved outlet section facing the inlet of the anti-vortex tube to suppress the tangential motion of the airflow upstream of the cavity, disrupt the development of high-speed vortices, and guide the airflow smoothly into the anti-vortex tube, reducing the pressure loss within the disk cavity. Several curved anti-vortex tubes are installed on the low-radius annular chuck and are coaxial with the compressor disk. The structure and installation radius of each tube are consistent. Each curved anti-vortex tube has a curved inlet and a straight outlet section, with the inlet facing the incoming flow direction to guide the airflow into the tube, thereby reducing the local loss at the inlet of the anti-vortex tube and reducing the generation of rigid vortex structures within the anti-vortex tube, thus reducing pressure loss. Therefore, the novel composite vortex reduction system of this invention fully considers the flow field structure and aerodynamic characteristics within the disk cavity. This structure not only suppresses the development of high-speed vortices upstream of the disk cavity but also reduces the local losses at the inlet of the vortex reduction tube, thereby reducing the system's pressure loss. Compared with the combination of straight fins and straight vortex reduction tubes, the combination of curved fins and curved vortex reduction tubes can reduce the total pressure loss coefficient by 40% to 64%.

[0022] In addition, the drum hole used in this invention is an elongated oval hole stretched circumferentially along the drum, which effectively improves the flow capacity of airflow into the disk cavity; in this invention, the curved fins have a certain gap with the subsequent stage compressor in the axial direction, which effectively reduces the installation difficulty. Attached Figure Description

[0023] Figure 1 This is a partial cross-sectional view of the integral disc cavity according to the present invention;

[0024] Figure 2 This is a radial sectional view of the overall disk cavity of the present invention;

[0025] Figure 3 yes Figure 2 A schematic front view of the novel composite vortex reduction system shown.

[0026] Figure 4 yes Figure 3 A schematic enlarged view of point A in the novel composite vortex reduction system shown;

[0027] The meanings of the labels in the diagram are as follows:

[0028] 1 is the front-stage compressor disc, and 2 is the rear-stage compressor disc;

[0029] 3 is a curved fin, 31 is the straight inlet section, and 32 is the curved outlet section;

[0030] 4 is a curved vortex reducer, 41 is a curved inlet pipe, and 42 is a straight outlet pipe.

[0031] 5 is the annular chuck, 6 is the drum, and 61 is the drum hole. Detailed Implementation

[0032] To clearly illustrate the technical features of this patent, the following detailed description is provided through specific embodiments and in conjunction with the accompanying drawings.

[0033] like Figures 1 to 4 As shown, this embodiment provides a novel composite vortex reduction system for a compressor, arranged in the radial bleed section of an aero-engine compressor. The compressor includes: a front-stage compressor disk 1, a rear-stage compressor disk 2, and a drum 6 extending vertically along the outer periphery of the disk cavity. The two compressor disks and the drum form an internal cavity. A plurality of drum holes 61 are evenly arranged circumferentially on the drum 6. The number of drum holes 61 is N, where N is a natural number greater than 1. Each drum hole is used to introduce air. The novel composite vortex reduction system includes: a plurality of curved fins 3 and a plurality of curved vortex-reducing tubes 4. This invention uses curved fins 3 and curved vortex-reducing tubes 4 during the radial bleed process of the compressor to reduce pressure loss within the disk cavity.

[0034] Several curved fins 3 are mounted on the front-stage compressor disk 1 and located downstream of the several drum holes 61, and are evenly distributed along the 360° circumference of the front-stage compressor disk 1 and rotate with the cavity. Each curved fin 3 is coaxially mounted with the compressor disks on both sides. Figure 3 As shown, each curved fin 3 has the same geometry and installation radius. The number of curved fins 3 is n, where n is a natural number greater than 1. To reduce installation difficulty, the curved fins 3 are kept at a certain distance from the downstream compressor disk 2.

[0035] like Figure 3 and Figure 4 As shown, each curved fin 3 has an inlet straight section 31 and an outlet curved section 32. Each outlet curved section 32 faces the inlet of the curved de-vortex tube 4 to suppress the tangential motion of the airflow upstream of the cavity, disrupt the development of high-speed vortices, and guide the airflow smoothly into the de-vortex tube, thereby reducing the pressure loss in the disk cavity.

[0036] Several curved vortex deflectors 4 are fixedly mounted on the annular chuck 5 and located downstream of the several curved fins 3. They are evenly arranged circumferentially and extend radially along the annular chuck 5, and rotate together with the cavity. The inlet of the curved vortex deflector 4 faces the incoming flow direction to reduce the pressure loss caused by flow separation at the inlet of the curved vortex deflector. Each curved vortex deflector 4 is coaxial with the compressor discs on both sides.

[0037] The curved fins on the front-stage compressor disk have the same installation radius, and the inlet and outlet circles of each curved fin are coaxially aligned with the two side compressor disks. The curved vortex suppressors on the annular chuck have the same installation radius, and the circle of each curved vortex suppressor is coaxial with the annular chuck. The inlet of each curved fin is located at a swirl ratio close to 1. The outlet axis of each curved fin and the inlet center axis of the curved vortex suppressor are both generated by spline curves.

[0038] Each drum hole has an elongated oval cross-section, and each drum hole is configured to improve the flow capacity of gas at the drum hole.

[0039] like Figure 2 As shown, each curved vortex reducer 4 has the same geometric structure and installation radius, and the curved vortex reducers 4 have a uniform diameter in the radial direction. The number of curved vortex reducers 4 is m, where m is a natural number greater than 1. Figure 3 and Figure 4As shown, each curved vortex suppressor 4 has a curved inlet pipe 41 and a straight outlet pipe 42. Under normal compressor operation, the curved fins 3 and the curved vortex suppressor 4 rotate in the same direction, at the same speed, and coaxially with the compressor discs on both sides. The airflow enters the compressor disc cavity through the drum holes 61, is radially introduced through the curved fins 3 and the curved vortex suppressor 4, and is led out along the compressor axial channel. This novel composite vortex suppressor system, employing a combination of curved fins 3 and curved vortex suppressor 4, reduces the total pressure loss by 40% to 64% compared to current composite vortex suppressor systems combining straight fins and straight vortex suppressor pipes.

[0040] More specifically, such as Figure 4 As shown, the structural dimensions of the curved fin 3 and the curved anti-vortex tube 4 are displayed more clearly, for Figure 3 A partial magnification has been provided. In this embodiment, all the inlet straight segments 31 are located on the same circumference, and the angle α between the inlet straight segment 31 and the tangent of the circumference at the inlet straight segment 31 is 20° to 90°.

[0041] More specifically, in this embodiment, the angle β between the inlet plane of the curved inlet pipe 41 and the tangent of the circumference where the inlet center point of the curved inlet pipe 41 is located is 90°.

[0042] More specifically, the axis of the curved fin outlet curved section 32 forms an angle γ of 90° with the inlet plane of the curved inlet pipe 41.

[0043] There are many specific ways to implement this invention. The above description is only a preferred embodiment of this invention. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of this invention, and these improvements should also be considered within the scope of protection of this invention.

Claims

1. A novel composite vortex reduction system for a compressor, the novel composite vortex reduction system comprising a front-stage compressor disk (1), a rear-stage compressor disk (2), and an annular chuck (5) and a drum (6) fixedly connected between the two, the drum (6) being located outside the annular chuck (5), and having a plurality of drum holes (61) evenly distributed on the drum (6); the front-stage compressor disk (1), the rear-stage compressor disk (2), and the drum (6) forming an internal cavity; characterized in that, The internal cavity is also provided with a number of one-to-one corresponding curved fins (3) and curved vortex tubes (4), the curved fins (3) being located between the drum hole (61) and the curved vortex tubes (4); The curved fins (3) are fixedly connected to the surface of the front stage compressor disk (1) and are evenly arranged along its circumference. The curved fins (3) include an inlet straight section (31) and an outlet curved section (32) that are connected as one unit from the outside to the inside. The outlet curved section (32) is arranged towards the curved vortex tube (4). The curved vortex reducer (4) is connected to the annular chuck (5) and the curved vortex reducer (4) is evenly arranged along the circumference of the annular chuck (5). The curved vortex reducer (4) includes a curved inlet pipe (41) and a straight outlet pipe (42) that are connected as one unit from the outside to the inside. The curved fin outlet curved section (32) is connected to the curved inlet pipe (41), and the center lines of both are arc-shaped.

2. The novel composite vortex reduction system for compressors according to claim 1, characterized in that, A gap is left between the curved fins (3) and the surface of the subsequent stage compressor disk (2).

3. A novel composite vortex reduction system for compressors according to claim 1, characterized in that, All the entrance straight segments (31) are on the same circumference, and the angle α between the entrance straight segment (31) and the tangent of the circumference at the entrance straight segment (31) is 20° to 90°.

4. A novel composite vortex reduction system for compressors according to claim 1, characterized in that, The angle β between the inlet plane of the curved inlet pipe (41) and the tangent of the circumference where the center point of the inlet of the curved inlet pipe (41) is located is 90°.

5. A novel composite vortex reduction system for a compressor according to claim 4, characterized in that, The axis of the curved fin outlet curved section (32) forms an angle with the inlet plane of the curved inlet pipe (41). It is 90°.

6. A novel composite vortex reduction system for a compressor according to claim 1, characterized in that, The cross-sectional area of ​​the inner wall of the curved vortex tube (4) is consistent at all points.

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