A layout structure of a gear-driven turbofan engine compression system

Abstract

This invention discloses a gear-driven turbofan engine compression system layout structure, belonging to the field of aero-engine technology. The layout structure includes: a hub, a casing, a flow divider cone, a front rotor, a rear rotor, a fan stator, inlet guide vanes, a booster rotor, a booster stator, and a transition section. The hub is located inside the casing. The front rotor and the rear rotor are sequentially fixed to the front end of the hub. The flow divider cone is located behind the rear rotor. The inner side of the flow divider cone and the hub form an inner bypass duct, and the outer side of the flow divider cone and the hub and casing form an outer bypass duct. The fan stator is fixed between the outer side of the flow divider cone and the casing. The inlet guide vanes, the booster rotor, and the booster stator are sequentially fixed from front to back in the inner bypass duct. The transition section is located behind the booster stator in the inner bypass duct. A gear transmission system is provided inside the hub, which drives the front rotor, the rear rotor, and the booster rotor to rotate.

Description

Technical Field

[0001] This invention belongs to the field of aero-engine technology, specifically relating to a layout structure of a gear-driven turbofan engine compression system. Background Technology

[0002] To enhance the market competitiveness of both military and civilian turbofan engines and continuously pursue higher thermal and propulsive efficiencies, modern high-performance turbofan engines are constantly increasing their bypass ratio and overall pressure ratio. Simultaneously, to achieve greater environmental friendliness, increasingly stringent requirements for pollutant emissions and noise reduction are driving turbofan engine development towards lower cost, higher performance, and greater environmental friendliness. The compression system is one of the largest and heaviest components in a turbofan engine; its performance determines parameters such as the engine's thrust-to-weight ratio and fuel consumption rate, and significantly impacts the overall stability and reliability of the engine. Improving the stage pressure ratio and stage load of existing turbofan engine compression systems, while reducing their size, is an effective way to improve turbofan engine performance.

[0003] In the design of existing turbofan engine compression systems, in order to ensure flow capacity and efficiency, the fan speed is low and the radius is large. However, the matching booster stage has a low speed and a small radial dimension, and there is a long transition section between the high-pressure compressor and the booster stage, which greatly increases the weight of the engine and limits the aerodynamic performance of the compression system. Summary of the Invention

[0004] In order to overcome at least one of the defects of the prior art, break through the aerodynamic limit of the compression system, and maximize the performance of the compression system, this invention proposes a gear-driven turbofan engine compression system layout structure, which can improve the flow capacity of the turbofan engine and enable the compression system to work stably and efficiently. This layout is conducive to achieving better aerodynamic performance, and realizing higher economy and environmental friendliness.

[0005] The technical solution of this invention:

[0006] A gear-driven turbofan engine compression system layout structure includes: a hub, a casing, a splitter cone, a front rotor, a rear rotor, a fan stator, inlet guide vanes, a booster rotor, a booster stator, and a transition section;

[0007] The hub is located inside the casing; the front rotor and the rear rotor are fixed to the front end of the hub in sequence.

[0008] The flow divider cone is located behind the rear rotor; the inner side of the flow divider cone and the hub form an inner bypass duct, and the outer side of the flow divider cone and the hub and casing form an outer bypass duct.

[0009] The fan stator is fixed between the outer side of the flow divider cone and the casing. The aerodynamic noise can be further reduced by the rectification effect of the fan stator.

[0010] The internal structure consists of, from front to back, fixed inlet guide vanes, booster rotor, and booster stator;

[0011] The section following the pressurized stator in the inner channel is a transition section.

[0012] The hub is equipped with a gear transmission system, which is used to drive the front rotor, the rear rotor and the booster rotor to rotate.

[0013] Furthermore, the front and rear rotors have the same number of blades and are evenly distributed circumferentially. They are all low hub ratio, wide chord blades, which improve the flow and work capacity of the compression system through the tandem arrangement.

[0014] The front rotor inlet hub ratio is 0.25~0.35, and the aspect ratio is 1.0~1.5;

[0015] The front and rear rotor blades are arranged alternately, with the front rotor offset by 15% to 30% of the rotor pitch in the opposite direction of the rotation of the rear rotor, thereby achieving optimal interstage matching characteristics; the rotor pitch is the circumferential distance between two adjacent blades on the front rotor.

[0016] Furthermore, the fan stator adopts a composite sweeping design, with the sweeping range of different blade heights being 10%~25% of the axial chord length and the bending range being 3%~9% of the axial chord length, which is beneficial to reduce flow separation in the end region.

[0017] Furthermore, a set of booster rotors and a set of booster stators constitute a booster stage, and the number of booster stages is 1 to 3, with each booster stage consisting of a booster rotor and a booster stator in sequence;

[0018] The booster rotor adopts a multi-circular arc blade shape and a composite sweep design. The first half of the casing area of ​​the first-stage booster rotor is treated with a self-circulating casing, while the second half is treated with a circumferential groove, which helps to broaden the stable operating range at different speeds.

[0019] Furthermore, the pressurized stator adopts an integrated blade-body design, and the stator endwall is a non-axisymmetric curved surface with local concavity and convexity. The amplitude of the local concavity and convexity on the non-axisymmetric curved surface is 3% to 9% of the blade height.

[0020] The final stage booster stator has a turning angle of 40°~70° and adopts a composite sweep design to achieve high efficiency and margin.

[0021] Furthermore, the transition section is an S-shaped channel formed by the outer wall of the local hub and the inner wall of the splitter cone. The outer wall of the local hub and the inner wall of the splitter cone are fitted with Beizer curves and B-spline curves, with 3 to 8 free parameters. This allows for quick design, high accuracy, and suitability for optimization design, making it highly practical in terms of transition section styling.

[0022] Furthermore, the transition section inlet / outlet area ratio Aout / Ain is 0.8~1.2, the transition section inlet height / length ratio Hin / L is 0.3~0.7, the inlet radius / length ratio Rin / L is 1.6~2.0, and the radial drop pressure / length ratio ΔR / L is 0.5~1.0, which is an ultra-compact design.

[0023] Furthermore, a set of load-bearing plates is provided along the circumferential direction within the transition section. The load-bearing plates include N large plates and N small plates evenly distributed in the circumferential direction, where N is 4 to 8.

[0024] The large support plate is NACA blade profile, and the small support plate is double circular arc DCA blade profile, multi-circular arc MCA blade profile, or controllable diffuser blade profile CDA, which serve to de-swirl aerodynamics and provide structural support.

[0025] The circumferential position of the small support plate relative to the large support plate is 20%~80% of the support plate pitch, and the support plate pitch is the circumferential distance between two adjacent large blades or adjacent small blades.

[0026] Furthermore, the gear ratio of the gear transmission system 11 can be changed according to the actual working conditions, ranging from 3 to 9.

[0027] Furthermore, the bypass ratio of the compression system is 4.0 to 15.0; the bypass ratio is the flow rate of the outer bypass divided by the flow rate of the inner bypass.

[0028] Compared with the prior art, the beneficial effects of the present invention are:

[0029] The compression system of the present invention can be directly used in high-performance geared turbofan engines. It can improve the aerodynamic performance of the compression system, reduce the weight and fuel consumption of the turbofan engine, and increase the thrust-to-weight ratio of the aero engine while significantly reducing the size of the engine compression system. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the compression system layout of a gear-driven turbofan engine.

[0031] Figure 2 This is a schematic diagram of the fan stacking line of a gear-driven turbofan engine.

[0032] Figure 3 This is a schematic diagram of the multi-circular-arc blade profile of the turbofan engine's booster stage.

[0033] Figure 4 This is a schematic diagram of the large and small support plates of a gear-driven turbofan engine.

[0034] 1-Hub, 2-Casing, 3-Diverter cone, 4-Front rotor, 5-Rear rotor, 6-Fan stator, 7-Inlet guide vane, 8-Booster rotor, 9-Booster stator, 10-Transition section, 11-Gear transmission system, 12-Large support plate, 13-Small support plate. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of this invention, and are intended to explain the invention, not to limit it. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0036] The present invention aims to provide a compression system layout structure for a geared turbofan engine, which can improve the aerodynamic performance of the compression system, reduce the weight and fuel consumption of the turbofan engine, and increase the thrust-to-weight ratio of the aero engine while significantly reducing the size of the engine compression system.

[0037] Specifically, the layout structure of a gear-driven turbofan engine compression system according to the present invention is as follows: Figure 1 As shown, the implementation should include at least the following parts:

[0038] 1. Hub; 2. Casing; 3. Diverter cone; 4. Front rotor; 5. Rear rotor; 6. Fan stator; 7. Inlet guide vane; 8. Supercharger rotor; 9. Supercharger stator; 10. Transition section (see reference). Figure 1 .

[0039] In this invention, the compression system hub 1 is located inside the casing 2. The front rotor 4 and the rear rotor 5 are fixed at the front end of the hub 1. The front rotor 4 and the rear rotor 5 have the same number of blades and are evenly distributed along the circumference. They are all low hub ratio and wide chord blades with an inlet hub ratio of less than 0.5 and an aspect ratio of less than 2. The front rotor 4 and the rear rotor 5 form a tandem fan rotor, which improves the flow and work capacity of the compression system through the tandem arrangement.

[0040] The front rotor 4 of this invention has an inlet hub ratio of 0.3 and an aspect ratio of 1.2. The front and rear rotor blades are staggered, and the front rotor 4 is offset by 20% rotor pitch in the opposite direction of the rotation direction of the rear rotor 5, thereby achieving the best interstage matching characteristics. The rotor pitch is the circumferential distance between two adjacent blades on the front rotor.

[0041] The flow divider cone 3 of the present invention is located behind the rear rotor 5. The inner side of the flow divider cone 3 and the hub 1 form an inner duct, and the outer side of the flow divider cone and the hub and casing form an outer duct. The fan stator 6 is fixed between the outer side of the flow divider cone 3 and the casing 2. After the rectification effect of the fan stator 6, the aerodynamic noise can be further reduced.

[0042] The fan stator 6 of this invention adopts a composite sweeping design, with a sweeping range of 15% of the axial chord length and a bending range of 6% of the axial chord length for different blade heights, which is beneficial to reduce flow separation in the end region.

[0043] The inner channel of the present invention has an inlet guide vane 7, a booster rotor 8, and a booster stator 9 fixed in sequence from front to back; behind the booster stator 9 in the inner channel is a transition section 10, and a gear transmission system 11 is provided in the hub to drive the front rotor 4, the rear rotor 5 and the booster rotor 8 to rotate.

[0044] The present invention has two booster stages, each consisting of a booster rotor 8 and a booster stator 9. The booster rotor 8 employs a multi-arc blade profile and a composite swept-back design. The first-stage booster rotor casing area features a self-circulating casing for the front half of the chord length and a circumferential groove for the rear half, which helps to broaden the stable operating range at different speeds. Figure 3 As shown.

[0045] The booster stator 9 of this invention adopts an integrated blade-body design. The stator endwall is a non-axisymmetric curved surface with local concavity and convexity. The amplitude of the local concavity and convexity on the non-axisymmetric curved surface is 5% of the blade height. The final stage booster stator 9 has a turning angle of 60° and adopts a composite sweeping shape to achieve the purpose of high efficiency and margin.

[0046] The transition section 10 of this invention is an S-shaped channel formed by a portion of the outer wall of the hub and the inner wall of the splitter cone, as shown in [reference]. Figure 1 The outer wall of the hub and the inner wall of the splitter cone are fitted with Beizer curves and B-spline curves. The number of free parameters is 5, which can quickly carry out the design, with high accuracy and suitable for optimization design. It has significant practical value in the styling of the transition section.

[0047] The transition section 10 of this invention has an inlet / outlet area ratio of Aout / Ain of 1.1, an inlet height / length ratio of Hin / L of 0.5, an inlet radius / length ratio of Rin / L of 1.8, and a radial drop / length ratio of ΔR / L of 0.8, which is an ultra-compact design.

[0048] The transition section 10 of this invention is provided with a set of load-bearing support plates along the circumferential direction. These support plates include six large support plates 12 and six small support plates 13 evenly distributed circumferentially. The large support plates 12 are NACA blades, and the small support plates 13 are MCA multi-arc blades, serving to de-swirl aerodynamics and provide structural support. The circumferential position of the small support plate 13 relative to the large support plate 12 is 30% of the support plate pitch. The support plate pitch is the circumferential distance between two adjacent large blades or adjacent small blades, as shown in [reference needed]. Figure 4 ;

[0049] The gear ratio of the gear transmission system 11 of the present invention can be changed according to actual working conditions, and the range is 3 to 9.

[0050] The compression system of the present invention has a bypass ratio of 6.0; the bypass ratio is the flow rate of the outer bypass divided by the flow rate of the inner bypass.

[0051] The objectives of this invention have been fully and effectively achieved through the above embodiments. Those skilled in the art will understand that this invention includes, but is not limited to, the contents described in the accompanying drawings and the specific embodiments described above. Although the invention has been described with reference to what is currently considered the most practical and preferred embodiments, it should be understood that the invention is not limited to the disclosed embodiments, and any modifications that do not depart from the functional and structural principles of the invention will be included within the scope of the claims.

Claims

1. A layout structure for a gear-driven turbofan engine compression system, characterized in that: The layout structure includes: hub, casing, splitter cone, front rotor, rear rotor, fan stator, inlet guide vane, booster rotor, booster stator, and transition section; The hub is located inside the casing; the front rotor and the rear rotor are fixed to the front end of the hub in sequence. The flow divider cone is located behind the rear rotor; the inner side of the flow divider cone and the hub form an inner bypass duct, and the outer side of the flow divider cone and the hub and casing form an outer bypass duct. The fan stator is fixed between the outer side of the shunt cone and the casing; The internal structure consists of, from front to back, fixed inlet guide vanes, booster rotor, and booster stator; The section following the pressurized stator in the inner channel is a transition section; The hub is equipped with a gear transmission system, which is used to drive the front rotor, the rear rotor and the booster rotor to rotate. The front and rear rotors have the same number of blades, which are evenly distributed circumferentially, and both have low hub ratios and wide chords. The hub ratio at the inlet of the front rotor is 0.25~0.35, and the aspect ratio is 1.0~1.

5. The blades of the front and rear rotors are staggered, with the front rotor offset from the rear rotor in the opposite direction of rotation by 15%~30% of the rotor pitch. The rotor pitch is the circumferential distance between two adjacent blades on the front rotor. The booster rotor adopts a multi-arc blade profile and a composite sweep design; the booster stator adopts an integrated blade-body design, and the stator endwall is a non-axisymmetric curved surface with local concavity and convexity. The amplitude of the local concavity and convexity on the non-axisymmetric curved surface is 3% to 9% of the blade height; the final stage booster stator has a turning angle of 40° to 70° and adopts a composite sweep design.

2. The layout structure of the gear-driven turbofan engine compression system according to claim 1, characterized in that, The fan stator adopts a composite sweep design, with the sweep range of different blade heights being 10%~25% of the axial chord length and the bending range being 3%~9% of the axial chord length.

3. The layout structure of the gear-driven turbofan engine compression system according to claim 1, characterized in that, A set of booster rotors and a set of booster stators constitute a booster stage. The number of booster stages is 1 to 3, and each booster stage is composed of booster rotors and booster stators in sequence.

4. The layout structure of the gear-driven turbofan engine compression system according to claim 1, characterized in that, The transition section is an S-shaped channel formed by the local hub outer wall and the splitter cone inner wall; the local hub outer wall and the splitter cone inner wall are fitted with Beizer curves and B-spline curves, with 3 to 8 free parameters.

5. The layout structure of the gear-driven turbofan engine compression system according to claim 4, characterized in that, The ratio of the inlet and outlet area of ​​the transition section, Aout / Ain, is 0.8~1.2; the ratio of the inlet height to the length of the transition section, Hin / L, is 0.3~0.7; the ratio of the inlet radius to the length, Rin / L, is 1.6~2.0; and the ratio of the radial drop pressure to the length, ΔR / L, is 0.5~1.

0.

6. The layout structure of the gear-driven turbofan engine compression system according to claim 5, characterized in that, A set of load-bearing plates is provided along the circumferential direction within the transition section. The load-bearing plates include N large plates and N small plates evenly distributed in the circumferential direction, where N is 4 to 8. The large support plate is NACA blade profile, and the small support plate is double circular arc blade profile DCA, multi-circular arc blade profile MCA or controllable diffusion blade profile CDA. The circumferential position of the small support plate relative to the large support plate is 20%~80% of the support plate pitch, and the support plate pitch is the circumferential distance between two adjacent large blades or adjacent small blades.

7. The layout structure of the gear-driven turbofan engine compression system according to claim 1, characterized in that, The gear ratio range of the gear transmission system is 3 to 9.

8. The layout structure of the gear-driven turbofan engine compression system according to claim 1, characterized in that, The bypass ratio of the compression system is 4.0 to 15.0; the bypass ratio is the flow rate of the outer bypass divided by the flow rate of the inner bypass.

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