Large-bypass-ratio turbofan engine power system based on rotary casing and design method

Abstract

The invention discloses a large-bypass-ratio turbofan engine power system based on a rotary casing and a design method, relates to the field of aero-engines, and solves the problems that the noise is increased, the efficiency is reduced, the strength limit of materials is exceeded, the rotor dynamics is increased and the like due to the fact that the blade tip tangential speed of a turbofan engine is correspondingly increased due to the increase of the size of an existing fan. The system comprises a fan, a first-stage compressor, a rotary casing and the like, the fan is arranged on the inner side of the outer end face of the static casing, one outlet end of the fan is communicated with an outer duct, and the other outlet end of the fan is communicated with the inlet end of the low-pressure compressor; and the rotary casing is respectively connected with the first-stage gas compressor and the first-stage low-pressure turbine. The fan is connected with the low-stage gas compressor and the low-pressure turbine through a transmission shaft; the high-pressure compressor is connected with the high-pressure turbine through a transmission shaft; the combustion chamber is fixed to the inner side of the inner end face of the static casing. An inlet of the exhaust nozzle is connected with an outlet of the primary low-pressure turbine. The method is also suitable for the field of designing the fan size of a turbofan engine by using a rotary casing.

Description

Technical Field

[0001] The present invention relates to the technical field of aero-engines, and particularly relates to a power system and a design method of a high-bypass ratio turbofan engine based on a rotating casing. Background Art

[0002] High-bypass ratio turbofan engines have the advantages of high efficiency, low fuel consumption rate, large thrust, low noise, long range, high reliability, etc., and are the research and application hotspots in the field of aero-engines. Among them, the outer diameter of the fan and the tip speed are important parameters affecting the aerodynamic performance. As the bypass ratio increases, the outer diameter of the fan usually increases to provide a larger air flow rate.

[0003] However, nowadays, modern high-bypass ratio turbofan engines have to reduce the number of fan blades in order to reduce weight and improve aerodynamic efficiency. At the same time, the increase in the fan radius also makes the tip tangential speed of the turbofan engine increase accordingly, resulting in increased noise, reduced efficiency, and may also exceed the strength limit of the material.

[0004] In addition, the fan and the low-pressure turbine are usually mechanically connected and rotate at the same speed. If the fan size is too large, the low-pressure turbine also needs to be increased, which will cause the flow path between the high-pressure and low-pressure turbines to become steeper, increasing the rotor dynamics problems. For the above reasons, a power system of a high-bypass ratio turbofan engine based on a rotating casing is proposed to reduce the fan size. Summary of the Invention

[0005] The present invention aims to solve the problems in the prior art that the increase in the fan size makes the tip tangential speed of the turbofan engine increase accordingly, resulting in increased noise, reduced efficiency, and may also exceed the strength limit of the material, as well as increasing rotor dynamics and other problems.

[0006] To solve the above technical problems, the present invention is realized through the following technical solutions:

[0007] Solution 1: The present invention proposes a power system of a high-bypass ratio turbofan engine based on a rotating casing. The power system of the high-bypass ratio turbofan engine based on a rotating casing includes a fan, a first-stage compressor, a rotating casing, a low-pressure compressor, a high-pressure compressor, a combustion chamber, a high-pressure turbine, a low-pressure turbine, a first-stage low-pressure turbine, a tail nozzle, an inner end face of the stationary casing, and an outer end face of the stationary casing;

[0008] The fan is arranged inside the outer end face of the stationary casing. One outlet end of the fan communicates with the outer bypass duct, and the other outlet end communicates with the inlet end of the low-pressure compressor;

[0009] The low-pressure compressor, the high-pressure compressor, the combustion chamber, the high-pressure turbine, the low-pressure turbine, the first-stage low-pressure turbine, and the tail nozzle are arranged in sequence axially;

[0010] The first-stage compressor and the first-stage low-pressure turbine are provided with a tip casing, and the tip casing is fixedly connected to the rotating casing;

[0011] The fan is connected to the low-pressure compressor and the low-pressure turbine through a transmission shaft;

[0012] The high-pressure compressor is connected to the high-pressure turbine through a transmission shaft;

[0013] The combustion chamber is fixed inside the inner end face of the stationary casing; the inlet of the tail nozzle is connected to the outlet of the first-stage low-pressure turbine.

[0014] Further, a preferred embodiment is provided. A third duct is provided between the outer end face of the stationary casing and the rotating casing; the first-stage compressor is located on the third duct; the first-stage low-pressure turbine is located inside the inner end face of the stationary casing.

[0015] Further, a preferred embodiment is provided. The rotating casing is driven to rotate by the first-stage low-pressure turbine.

[0016] Further, a preferred embodiment is provided. The fan is axially arranged and located in front of the inner end face of the stationary casing; the low-pressure compressor, the high-pressure compressor, the combustion chamber, the high-pressure turbine, the low-pressure turbine, the first-stage low-pressure turbine, and the tail nozzle are inside the inner end face of the stationary casing.

[0017] Further, a preferred embodiment is provided. The fan, the first-stage compressor, the low-pressure compressor, the high-pressure compressor, the combustion chamber, the high-pressure turbine, the low-pressure turbine, the first-stage low-pressure turbine, the tail nozzle, the inner end face of the stationary casing, and the outer end face of the stationary casing are respectively arranged inside the rotating casing.

[0018] Further, a preferred embodiment is provided. The system further includes steps for optimizing the design of the ratio of the diameter of the rotating casing to the diameter of the fan.

[0019] Further, a preferred embodiment is provided. The first-stage compressor further includes steps for adjusting the power under different flight conditions.

[0020] Solution 2: A design method for the power system of a high-bypass ratio turbofan engine based on a rotating casing according to any one of the solutions in Solution 1, the design method includes the following steps:

[0021] Design the operating condition parameters, calculate the specific fuel consumption and the specific thrust of the power system of the high-bypass ratio turbofan engine based on the rotating casing, and obtain the optimal specific fuel consumption and specific thrust by comparing the specific fuel consumption and specific thrust calculated for the power system of the high-bypass ratio turbofan engine and other engine power systems.

[0022] Further, a preferred embodiment is provided, where the operating parameters include flight altitude, fan pressure ratio, and the third bypass ratio.

[0023] The advantages of the present invention are as follows:

[0024] In the large bypass ratio turbofan engine power system based on a rotating casing according to the present invention, the rotating casing is applied to the turbofan engine power system solution. Using the rotating casing reduces the fan size of the existing turbofan engine. While effectively reducing the tip tangential velocity and reducing aerodynamic noise, it also reduces the forces on the blades and the casing, lowering the requirements for the structural strength of the fan material and the manufacturing cost. At the same time, it reduces the centrifugal force and vibration amplitude of the internal rotor, thereby reducing rotor dynamics problems.

[0025] With the rotating casing design of the present invention, on the basis of maintaining the existing fan design level of the turbofan engine, by increasing the third bypass duct, the bypass ratio of the turbofan engine is further increased, which is beneficial to improving the output power and thermal efficiency of the engine system. Furthermore, it reduces the fuel consumption rate of the turbofan engine and decreases the flight cost of the aircraft.

[0026] The present invention is also applicable to the field of designing the fan size of turbofan engines using a rotating casing. Description of the Drawings

[0027] Figure 1 It is a schematic diagram of the overall structure of a large bypass ratio turbofan engine power system based on a rotating casing described in Embodiment 1. Specific Embodiments

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application.

[0029] Embodiment 1. This embodiment proposes a large bypass ratio turbofan engine power system based on a rotating casing. The large bypass ratio turbofan engine power system based on a rotating casing includes a fan 1, a first-stage compressor 2, a rotating casing 3, a low-pressure compressor 5, a high-pressure compressor 6, a combustion chamber 7, a high-pressure turbine 8, a low-pressure turbine 9, a first-stage low-pressure turbine 4, a tail pipe 10, a stationary casing inner end face 11, and a stationary casing outer end face 12;

[0030] The fan 1 is arranged inside the stationary casing outer end face 12. One outlet end of the fan 1 is communicated with the outer bypass duct, and the other outlet end is communicated with the inlet end of the low-pressure compressor 5;

[0031] The low-pressure compressor 5, high-pressure compressor 6, combustion chamber 7, high-pressure turbine 8, low-pressure turbine 9, first-stage low-pressure turbine 4, and tail nozzle 10 are arranged axially in sequence;

[0032] The first-stage compressor 2 and the first-stage low-pressure turbine 4 are provided with tip casings, and the tip casings are fixedly connected to the rotating casing 3;

[0033] The fan 1 is connected to the low-pressure compressor 5 and the low-pressure turbine 9 through a transmission shaft;

[0034] The high-pressure compressor 6 is connected to the high-pressure turbine 8 through a transmission shaft;

[0035] The combustion chamber 7 is fixed inside the inner end face 11 of the stationary casing; the inlet of the tail nozzle 10 is connected to the outlet of the first-stage low-pressure turbine 4.

[0036] Embodiment 2: This embodiment further limits the large bypass ratio turbofan engine power system based on the rotating casing described in Embodiment 1. A third duct is provided between the outer end face 12 of the stationary casing and the rotating casing 3; the first-stage compressor 2 is located on the third duct; the first-stage low-pressure turbine 4 is located inside the inner end face 11 of the stationary casing.

[0037] Embodiment 3: This embodiment further limits the large bypass ratio turbofan engine power system based on the rotating casing described in Embodiment 1. The rotating casing 3 is driven to rotate by the first-stage low-pressure turbine 4.

[0038] Embodiment 4: This embodiment further limits the large bypass ratio turbofan engine power system based on the rotating casing described in Embodiment 1. The fan 1 is arranged axially and is located in front of the inner end face 11 of the stationary casing; the low-pressure compressor 5, high-pressure compressor 6, combustion chamber 7, high-pressure turbine 8, low-pressure turbine 9, first-stage low-pressure turbine 4, and tail nozzle 10 are inside the inner end face 11 of the stationary casing.

[0039] Embodiment 5: This embodiment further limits the large bypass ratio turbofan engine power system based on the rotating casing described in Embodiment 1. The fan 1, first-stage compressor 2, low-pressure compressor 5, high-pressure compressor 6, combustion chamber 7, high-pressure turbine 8, low-pressure turbine 9, first-stage low-pressure turbine 4, tail nozzle 10, inner end face 11 of the stationary casing, and outer end face 12 of the stationary casing are respectively arranged inside the rotating casing 3.

[0040] Embodiment 6: This embodiment further limits the large bypass ratio turbofan engine power system based on the rotating casing described in Embodiment 1. The system further includes steps for optimizing the design of the ratio of the diameter of the rotating casing 3 to the diameter of the fan 1.

[0041] Embodiment 7. This embodiment further defines the large bypass ratio turbofan engine power system based on a rotating casing described in Embodiment 6. The value range of the ratio of the diameter of the rotating casing 3 to the diameter of the fan 1 is from 0.1 to 0.4.

[0042] Embodiment 8. This embodiment further defines the large bypass ratio turbofan engine power system based on a rotating casing described in Embodiment 6. The first-stage compressor 2 further includes a step of adjusting the power for different flight conditions.

[0043] Embodiment 9. This embodiment proposes a design method for the large bypass ratio turbofan engine power system based on a rotating casing described in any one of Embodiments 1 to 8. The design method includes the following steps:

[0044] Design the working condition parameters, calculate the specific fuel consumption and specific thrust of the large bypass ratio turbofan engine power system based on a rotating casing, and obtain the optimal specific fuel consumption and specific thrust by comparing the specific fuel consumption and specific thrust calculated for the large bypass ratio turbofan engine power system and other engine power systems.

[0045] Embodiment 10. This embodiment further defines the design method for the large bypass ratio turbofan engine power system based on a rotating casing described in Embodiment 9. The working condition parameters include flight altitude, fan pressure ratio, and third bypass ratio.

[0046] Embodiment 11. This embodiment presents an example for explaining the above Embodiments 1 to 10. The example is specifically as follows:

[0047] See Figure 1Description of this embodiment: A high-bypass ratio turbofan engine power system based on a rotating casing. The aeroengine power system includes a fan, a first-stage compressor, a rotating casing, a low-pressure compressor, a high-pressure compressor, a combustion chamber, a high-pressure turbine, a low-pressure turbine, a first-stage low-pressure turbine, a tail nozzle, an inner end face of the stationary casing, and an outer end face of the stationary casing. The fan is located inside the outer end face of the stationary casing. One outlet end communicates with the outer bypass duct, and the other outlet end communicates with the inlet end of the low-pressure compressor. The low-pressure compressor, high-pressure compressor, combustion chamber, high-pressure turbine, low-pressure turbine, first-stage low-pressure turbine, and tail nozzle are arranged in sequence axially. The tip casings of the first-stage compressor and the first-stage low-pressure turbine are fixedly connected to the rotating casing. The fan is connected to the low-stage compressor and the low-pressure turbine through a drive shaft. The high-pressure compressor is connected to the high-pressure turbine through a drive shaft. The combustion chamber is fixed inside the inner end face of the stationary casing. The inlet of the tail nozzle is connected to the outlet of the first-stage low-pressure turbine. The duct between the outer side of the outer end face of the stationary casing and the rotating casing is the third bypass duct. The first-stage compressor is located in the third bypass duct. The first-stage low-pressure turbine is located inside the inner end face of the stationary casing. The moving blades of the first-stage compressor and the first-stage low-pressure turbine are fixed to the tip casing and have a gap with the hub. The moving blades of the first-stage low-pressure turbine are driven by high-temperature and high-pressure gas during operation to drive the tip casing to rotate, and then drive the first-stage compressor to work.

[0048] Taking the commercially available CFM56-5C2 engine as a comparative example, the specific fuel consumption and specific thrust of the high-bypass ratio turbofan engine power system based on the rotating casing are calculated zero-dimensionally. Among them, the design conditions are a flight altitude of 10.7 km, a flight Mach number of 0.8, a fan pressure ratio of 2.24, a bypass ratio of 6.6, and a third bypass ratio of 2.0. The results are shown in Table 1.

[0049] Table 1 Comparison of performance indicators of different engine power systems

[0050]

[0051]

[0052] It can be seen from the results in Table 1 that the specific fuel consumption of the high-bypass ratio turbofan engine power system based on the rotating casing is lower than that of the CFM56-5C2 engine. This shows that the engine power system of the present invention can achieve lower energy consumption under the premise of the same environmental conditions, reducing the flight cost.

[0053] In addition, the specific thrust of the engine power system of the present invention is higher than that of the CFM56-5C2 engine, improving the efficiency of the engine. Considering all indicators, the high-bypass ratio turbofan engine power system based on the rotating casing is a product with more excellent performance than the traditional turbofan engine power system.

[0054] Those skilled in the art can understand that the above description is only the preferred embodiment of the present invention. The features described in each embodiment and / or claim of the present disclosure can be combined or combined in various ways, even if such combinations or combinations are not explicitly recorded in the present disclosure. It is not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or equivalently replace some of the technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0055] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications once they learn the basic creative concept. Therefore, the appended claims are intended to be construed as including the preferred embodiments and all changes and modifications falling within the scope of the present invention. Obviously, those skilled in the art can make various changes and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A high bypass ratio turbofan engine power system based on a rotating casing, characterized in that: The high bypass ratio turbofan engine power system based on a rotating casing comprises a fan (1), a first-stage compressor (2), a rotating casing (3), a low-pressure compressor (5), a high-pressure compressor (6), a combustion chamber (7), a high-pressure turbine (8), a low-pressure turbine (9), a first-stage low-pressure turbine (4), a tail nozzle (10), a stationary casing inner end surface (11) and a stationary casing outer end surface (12); The fan (1) is arranged on the inner side of the outer end surface (12) of the stationary casing, one outlet end of the fan (1) is connected to the outer duct, and the other outlet end is connected to the inlet end of the low-pressure compressor (5); The low-pressure compressor (5), the high-pressure compressor (6), the combustion chamber (7), the high-pressure turbine (8), the low-pressure turbine (9), the first-stage low-pressure turbine (4), and the tail nozzle (10) are arranged in sequence in the axial direction; The first-stage compressor (2) and the first-stage low-pressure turbine (4) are provided with a blade tip casing, and the blade tip casing is fixedly connected to the rotating casing (3); The fan (1) is connected to the low-stage compressor (5) and the low-pressure turbine (9) via a transmission shaft; The high-pressure compressor (6) is connected to the high-pressure turbine (8) via a transmission shaft; The combustion chamber (7) is fixed to the inner side of the inner end surface (11) of the stationary casing; the inlet of the tail nozzle (10) is connected to the outlet of the first-stage low-pressure turbine (4).

2. The high bypass ratio turbofan engine power system based on a rotating casing according to claim 1, characterized in that: A third duct is provided between the outer end surface (12) of the stationary casing and the rotating casing (3); the first-stage compressor (2) is located on the third duct; and the first-stage low-pressure turbine (4) is located on the inner side of the inner end surface (11) of the stationary casing.

3. The high bypass ratio turbofan engine power system based on a rotating casing according to claim 1, characterized in that: The rotating casing (3) is driven to rotate by a first-stage low-pressure turbine (4).

4. The high bypass ratio turbofan engine power system based on a rotating casing according to claim 1, characterized in that: The fan (1) is arranged in the axial direction and is located in front of the inner end surface (11) of the stationary casing; the low-pressure compressor (5), the high-pressure compressor (6), the combustion chamber (7), the high-pressure turbine (8), the low-pressure turbine (9), the first-stage low-pressure turbine (4), and the tail nozzle (10) are located on the inner side of the inner end surface (11) of the stationary casing.

5. The high bypass ratio turbofan engine power system based on a rotating case according to claim 1, characterized in that: The fan (1), the first-stage compressor (2), the low-pressure compressor (5), the high-pressure compressor (6), the combustion chamber (7), the high-pressure turbine (8), the low-pressure turbine (9), the first-stage low-pressure turbine (4), the tail nozzle (10), the inner end surface (11) of the stationary casing and the outer end surface (12) of the stationary casing are respectively arranged on the inner side of the rotating casing (3).

6. The high bypass ratio turbofan engine power system based on a rotating case according to claim 1, characterized in that: The system also includes a step of optimizing the design of the ratio of the diameter of the rotating casing (3) to the diameter of the fan (1).

7. The high bypass ratio turbofan engine power system based on a rotating casing according to claim 6, characterized in that: The ratio of the diameter of the rotating casing (3) to the diameter of the fan (1) ranges from 0.1 to 0.

4.

8. The high bypass ratio turbofan engine power system based on a rotating case according to claim 1, characterized in that: The first-stage compressor (2) also includes a step of adjusting power according to different flight conditions.

9. A design method for a high bypass ratio turbofan engine power system based on a rotating casing according to any one of claims 1 to 8, characterized in that: The design method comprises the following steps: Design operating parameters, calculate the fuel consumption rate and unit thrust of a high bypass ratio turbofan engine power system based on a rotating casing, and obtain the optimal fuel consumption rate and unit thrust by comparing the high bypass ratio turbofan engine power system with the calculated fuel consumption rate and unit thrust of other engine power systems.

10. The design method of a high bypass ratio turbofan engine power system based on a rotating casing according to claim 9, characterized in that: The operating parameters include flight altitude, fan pressure ratio and third bypass ratio.

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