Core engine nozzle and core engine, aircraft engine

Abstract

The application discloses a core engine nozzle, a core engine and an aero-engine. The core engine nozzle comprises a tail cone body and a nozzle outer cylinder. The core engine nozzle further comprises a tail cone sleeve which is sleeved on the outer surface of the tail cone body. The outer surface of the tail cone sleeve is composed of a type line I, a type line II and a connecting point. The type line I is tangent to the outer surface of the tail cone body. The type line I and the type line II are smoothly connected by the connecting point. The connecting point and the end wall of the nozzle outer cylinder form a throat section of the core engine nozzle. The main flow of the core engine nozzle is accelerated by expansion and converges to the throat section along the type line I and then is further expanded along the type line II. In this process, the airflow is accelerated by expansion along the outer surface of the tail cone sleeve without shock wave and airflow separation. The end static pressure of the tail cone body is less than the ambient pressure, which is beneficial to the exhaust gas discharge of the bearing cavity.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of aero-engines, in particular to a core engine nozzle, a core engine and an aero-engine. BACKGROUND

[0002] The core engine nozzle is an important device for core engine test of an aero-engine, which is used to guide the high-temperature gas flow after the turbine to the ambient atmosphere, and can adjust the working characteristics of the three main components (compressor, combustor and turbine) of the engine by changing the throat area.

[0003] However, due to the characteristics of large inlet gas flow pressure (falling pressure ratio close to 7-9) and high temperature (total temperature close to 1000K-1200K) of the civil aero-engine core nozzle, the tail cone surface of the core nozzle will cause air flow diversion due to shock boundary layer interference, resulting in large pressure at the end of the tail cone and causing poor exhaust of the bearing cavity. In order to avoid the above problems, the existing core nozzle generally adopts the method of further extending the tail cone of the nozzle, which makes the core nozzle too long, difficult to guarantee the strength, large loss of high-temperature alloy material, high cost, difficult to assemble and other pain point problems. SUMMARY

[0004] The technical problem to be solved by the present application is to overcome the defect of air flow diversion on the tail cone surface of the existing core nozzle, and to provide a core nozzle, a core engine and an aero-engine.

[0005] The present application solves the above technical problems by the following technical scheme:

[0006] A core nozzle, comprising a tail cone body and a nozzle outer cylinder, the core nozzle further comprising a tail cone sleeve, the tail cone sleeve being sleeved on the outer surface of the tail cone body, the outer surface of the tail cone sleeve being composed of a contour line I, a contour line II and a connecting point, the contour line I being tangent to the outer surface of the tail cone body, the contour line I and the contour line II being smoothly tangent connected through the connecting point, and the connecting point and an end wall of the nozzle outer cylinder forming a throat section of the core nozzle.

[0007] In the technical scheme, the main flow of the core nozzle is accelerated by expansion, converges to the throat section through the contour line I, reaches the sound speed at the throat section, and then further expands along the contour line II until the end of the tail cone sleeve, and the air flow is close to complete expansion and the pressure is close to the ambient pressure. In this process, the air flow is accelerated by expansion along the outer surface of the tail cone sleeve, and there is no shock and no air flow separation throughout the process, and the static pressure at the end of the tail cone body is less than the ambient pressure, which is beneficial to the exhaust of the bearing cavity.

[0008] Preferably, the core engine nozzle further comprises a tail cone sleeve accessory, the tail cone sleeve accessory is sleeved on the outer surface of the tail cone sleeve, and the outer surface of the tail cone sleeve accessory is composed of the contour I, the contour II and the junction point. The tail cone sleeve accessory is selected from any one of a sleeve accessory assembly composed of tail cone sleeve accessories of different specifications.

[0009] In the technical solution, the outer surface of the tail cone sleeve accessory is also composed of the contour I, the contour II and the junction point after being sleeved on the outer surface of the tail cone sleeve, so that the throat cross-sectional area of the core engine nozzle can be changed, and the starting and accelerating performance of the core engine can be analyzed.

[0010] Preferably, the contour I is generated by a cubic Bezier curve equation, and the contour II is generated by a characteristic line method.

[0011] In the technical solution, the contour I is generated by a Bezier curve equation, and the contour I can be a smooth curve drawn according to coordinates of four points at any positions, and the contour II is generated by a characteristic line method, and the characteristic line method can determine the parameter change of supersonic airflow expansion or compression according to the change relationship of airflow parameters along the characteristic line.

[0012] Preferably, the inner side of the tail cone sleeve is attached to the outer surface of the tail cone body.

[0013] In the technical solution, the tail cone sleeve is not prone to deformation under the impact of high-pressure airflow because the tail cone body supports the inner side of the tail cone sleeve.

[0014] Preferably, the tail cone sleeve and the tail cone body are detachably connected.

[0015] In the technical solution, if the tail cone sleeve is damaged under the impact of high-pressure airflow, the tail cone sleeve is convenient to repair and replace.

[0016] Preferably, the tail cone sleeve is selected from any one of a sleeve assembly composed of tail cone sleeves of different specifications.

[0017] In the technical solution, tail cone sleeves of different specifications are selected from the sleeve assembly for disassembly and replacement, so that the throat area of the core engine nozzle can be changed to adapt to the needs of engine core performance debugging.

[0018] Preferably, the end of the tail cone body is aligned with the other end of the contour II relative to the junction point.

[0019] In the technical solution, the length of the tail cone body can be avoided to be too long, the high-temperature alloy material is saved, and the manufacturing cost of the core engine nozzle is reduced.

[0020] Preferably, the tail cone body is provided with an anti-backflow baffle at the tail end, the end wall of the anti-backflow baffle abuts against the inner surface of the tail cone body, and the anti-backflow baffle is provided with an exhaust portion penetrating through the anti-backflow baffle.

[0021] In the technical solution, the anti-backflow baffle is arranged to prevent the main flow from the throat from returning to the inner cavity of the tail cone body, and the exhaust portion arranged on the anti-backflow baffle is conducive to the discharge of oil mist and exhaust gas from the inner cavity of the tail cone body into the ambient atmosphere.

[0022] Preferably, the exhaust portion is a plurality of exhaust grooves arranged in an axisymmetric array.

[0023] In the technical solution, the above structure is adopted, which is conducive to the uniform discharge of oil mist and exhaust gas in the tail cone body and the balance of the air pressure in the inner cavity of the tail cone body.

[0024] Preferably, the exhaust portion is located at a position with a radial height of 50% to 80% of the anti-backflow baffle.

[0025] At the position with a radial height of 50% to 80% of the anti-backflow baffle, the air flow pressure in the backflow area is lower than the ambient pressure. In the technical solution, the above structure is adopted, which is conducive to the smooth discharge of oil mist and exhaust gas in the tail cone body.

[0026] Preferably, the inner side of the anti-backflow baffle is provided with a flow guide cone, the bottom of the flow guide cone is fixedly connected to the anti-backflow baffle and located inside the array formed by the plurality of exhaust grooves, and the tip of the flow guide cone extends from the anti-backflow baffle to the inner cavity of the tail cone body.

[0027] In the technical solution, the above structure is adopted, the bottom of the flow guide cone with a large area is located inside the array formed by the plurality of exhaust grooves, and the tip of the flow guide cone extends to the inner cavity of the tail cone body. The oil mist and exhaust gas in the tail cone body can be compressed from a position with a large space to the exhaust grooves along the outer surface of the flow guide cone, thereby facilitating the discharge of oil mist and exhaust gas.

[0028] A core engine comprises the core engine nozzle.

[0029] In the technical solution, the above structure is adopted. During the expansion and acceleration of the air flow along the outer surface of the tail cone sleeve, there is no shock wave and no air flow separation, and the static pressure at the tail end of the tail cone body is lower than the ambient pressure, which is conducive to the discharge of exhaust gas from the bearing cavity.

[0030] An aero-engine comprises the core engine.

[0031] In the technical solution, the airflow in the aero-engine expands and accelerates along the outer surface of the tail cone sleeve pipe without shock wave and airflow separation, the end static pressure of the tail cone body is less than the ambient pressure, and the exhaust gas in the bearing cavity is discharged.

[0032] The positive progress effect of the application is that the main flow of the core engine nozzle expands and accelerates, converges to the throat section through the profile I, reaches the sound speed at the throat section, and then further expands along the profile II until the end of the tail cone sleeve pipe, and the airflow is close to complete expansion and the pressure is close to the ambient pressure. In this process, the airflow expands and accelerates along the outer surface of the tail cone sleeve pipe without shock wave and airflow separation, the end static pressure of the tail cone body is less than the ambient pressure, and the exhaust gas in the bearing cavity is discharged. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 The figure is a structural schematic diagram of the core engine nozzle in the embodiment one.

[0034] Figure 2 The figure is another structural schematic diagram of the core engine nozzle in the embodiment one.

[0035] Figure 3 The figure is another structural schematic diagram of the core engine nozzle in the embodiment one.

[0036] Figure 4 The figure is a main flow schematic diagram of the core engine nozzle in the embodiment one.

[0037] Figure 5 The figure is a main flow and backflow schematic diagram of the core engine nozzle in the embodiment one.

[0038] Figure 6 The figure is a pressure ratio schematic diagram of the anti-backflow baffle in the radial height of the core engine nozzle in the embodiment one.

[0039] Figure 7 The figure is an airflow separation schematic diagram of the traditional configuration core engine nozzle.

[0040] Figure 8 The figure is a structural schematic diagram of the core engine nozzle in the embodiment two.

[0041] MARK DESCRIPTION

[0042] Tail cone body 1

[0043] Nozzle outer cylinder 2

[0044] Casing inner wall 3

[0045] Casing outer wall 4

[0046] Tail cone sleeve pipe 5

[0047] Anti-backflow baffle 6

[0048] Exhaust part 61

[0049] Diverging cone 7

[0050] Tail vertebrae sleeve cap accessory 51 DETAILED DESCRIPTION

[0051] The present application is further illustrated by the following examples without thereby limiting the present application to the examples.

[0052] Example one:

[0053] As Figures 1-3 shown, a core engine nozzle is in axisymmetric revolution, including a tail cone body 1 and a nozzle outer cylinder 2 from inside to outside, the front end of the tail cone body 1 is fixedly connected with the inner wall 3 of the turbine rear casing through flange and bolt, the front end of the nozzle outer cylinder 2 is fixedly connected with the outer wall 4 of the turbine rear casing through flange and bolt, the main flow path is formed between the tail cone body 1 and the nozzle outer cylinder 2 for guiding the high-temperature gas at the turbine outlet to be discharged into the environment atmosphere, the core engine nozzle further includes a tail cone sleeve 5, which is also in axisymmetric revolution and is sleeved on the outer surface of the tail cone body 1, and the rear end is connected with the tail cone body 1 through bolt. The outer surface of the tail cone sleeve 5 is smoothly connected by two different profile lines, specifically, including a profile line I, a profile line II and a connecting point, the profile line I is tangent to the outer surface of the tail cone body 1, the profile line I and the profile line II are smoothly tangent and connected through the connecting point, and the connecting point and the end wall of the nozzle outer cylinder 2 form the throat section of the core engine nozzle.

[0054] The conventional configuration core engine nozzle will appear airflow separation in the working process, referring to Figure 7 In the embodiment, the above structure is adopted, as Figure 4 shown, the main flow of the core engine nozzle is accelerated by expansion, converges to the throat section through the profile line I, reaches the sound speed at the throat section, and then further expands along the profile line II until the end of the tail cone sleeve 5, the airflow is close to complete expansion, and the pressure is close to the ambient pressure. In this process, the airflow is accelerated by expansion along the outer surface of the tail cone sleeve 5 without shock wave and airflow separation throughout the process, and the static pressure at the end of the tail cone body 1 is less than the ambient pressure, which is beneficial to the exhaust gas discharge of the bearing cavity. Of course, in other embodiments, the tail cone sleeve 5 can be connected on the tail cone body 1 through other ways such as buckle to achieve the same effect.

[0055] As a preferred embodiment, the tail cone sleeve 5 is detachably connected with the tail cone body 1.

[0056] In the embodiment, the above structure is adopted, if the tail cone sleeve 5 is damaged under the impact of high-pressure airflow, it is convenient for maintenance and replacement.

[0057] As a preferred implementation, the tail cone sleeve 5 is selected from any one of the sleeve assembly composed of tail cone sleeves 5 of different specifications.

[0058] In this embodiment, the above structure is adopted, and tail cone sleeves 5 of different specifications are selected from the sleeve assembly for disassembly and replacement, so that the core engine nozzle throat area can be changed to adapt to the needs of engine core performance debugging.

[0059] As a preferred implementation, the contour I is generated by a cubic Bezier curve equation, and the contour II is generated by a characteristic line method.

[0060] In this embodiment, the above structure is adopted, the contour I is generated by a Bezier curve equation, and the contour I can be a smooth curve drawn according to the coordinates of four points at any positions. The contour II is generated by a characteristic line method, and the characteristic line method can determine the parameter changes when the supersonic airflow expands or compresses according to the variation relationship of the airflow parameters along the characteristic line.

[0061] As a preferred implementation, the inner side of the tail cone sleeve 5 is attached to the outer surface of the tail cone body 1.

[0062] In this embodiment, the above structure is adopted, and the tail cone sleeve 5 is not prone to deformation under the impact of high-pressure airflow because the tail cone body 1 supports the inner side of the tail cone sleeve 5.

[0063] As a preferred implementation, the end of the tail cone body 1 is aligned with the other end of the contour II relative to the connection point.

[0064] In this embodiment, the above structure is adopted, which can avoid the tail cone body being too long, save the high-temperature alloy material, and reduce the manufacturing cost of the core engine nozzle.

[0065] As a preferred implementation, the end of the tail cone body 1 is provided with a circular plate-shaped backflow prevention baffle 6, the end wall of the backflow prevention baffle 6 abuts against the inner surface of the tail cone body 1, and the backflow prevention baffle 6 is fixedly connected with the rear end flange of the tail cone body 1 through bolts. The backflow prevention baffle 6 is provided with an exhaust portion 61, and the exhaust portion 61 penetrates the backflow prevention baffle 6.

[0066] In this embodiment, the above structure is adopted, and the backflow prevention baffle 6 can prevent the main flow from the throat from returning to the inner cavity of the tail cone body. In addition, the exhaust portion 61 provided on the backflow prevention baffle 6 is beneficial to the discharge of oil mist and exhaust gas from the inner cavity of the tail cone body into the environment.

[0067] As a preferred implementation, the exhaust portion 61 is a plurality of axisymmetrically arranged "C"-shaped exhaust grooves.

[0068] In this embodiment, the above-mentioned structural form is beneficial to the uniform discharge of oil mist and exhaust gas inside the coccyx body, and the air pressure in the internal cavity of the coccyx body is relatively balanced.

[0069] As a preferred embodiment, the "C"-shaped exhaust groove is located at a position of 50% to 80% of the radial height of the anti-backflow baffle 6.

[0070] like Figures 5-6 As shown, at a radial height of 50% to 80% of the anti-backflow baffle 6, the airflow pressure in the backflow zone is lower than the ambient pressure. In this embodiment, the above-mentioned structural form is adopted, which is conducive to the smooth discharge of oil mist and exhaust gas in the tailbone body.

[0071] In a preferred embodiment, an axisymmetrically rotating guide cone 7 is provided on the inner side of the anti-backflow baffle 6, with its front end facing the exhaust port of the core bearing cavity and its rear end fixedly connected to the inner side of the anti-backflow baffle 6 via a flange and bolts. The guide cone 7 is located inside an array composed of multiple exhaust grooves, and the tip of the guide cone 7 extends from the anti-backflow baffle 6 into the inner cavity of the tailbone body.

[0072] In this embodiment, the above-described structure is adopted. The bottom of the guide cone 7, which has a larger area, is located inside the array composed of multiple exhaust slots. The tip of the guide cone 7 extends into the inner cavity of the tailbone body. The oil mist and exhaust gas inside the tailbone body can be compressed from the larger space along the outer surface of the guide cone 7 to the exhaust slot, which facilitates the discharge of oil mist and exhaust gas.

[0073] A core engine, including the aforementioned core engine nozzle.

[0074] In this embodiment, with the above-mentioned structure, during the process of the airflow in the core machine expanding and accelerating along the outer surface of the tail cone sleeve 5, there is no shock wave or airflow separation. The static pressure at the end of the tail cone body 1 is less than the ambient pressure, which is conducive to the discharge of exhaust gas from the bearing cavity.

[0075] An aircraft engine, including the aforementioned core engine.

[0076] In this embodiment, with the above-mentioned structure, during the process of the airflow in the aero-engine expanding and accelerating along the outer surface of the tail cone sleeve 5, there is no shock wave or airflow separation. The static pressure at the end of the tail cone body 1 is less than the ambient pressure, which is conducive to the discharge of exhaust gas from the bearing cavity.

[0077] Example 2:

[0078] like Figure 8As shown: the core engine nozzle includes a tail cone sleeve attachment 51, the tail cone sleeve attachment 51 is directly sleeved on the outer surface of the tail cone sleeve 5, the outer surface of the tail cone sleeve attachment 51 is also composed of the contour I, the contour II and the connecting point, and the tail cone sleeve attachment 51 is selected from any one of the sleeve attachment assembly composed of tail cone sleeve attachments 51 of different specifications. After the tail cone sleeve attachment 51 is sleeved on the outer surface of the tail cone sleeve 5, the throat cross-sectional area of the core engine nozzle can also be changed to analyze the starting and accelerating performance of the core engine.

[0079] Although the specific embodiments of the present application are described above, those skilled in the art should understand that this is only an example, the protection scope of the present application is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present application, and these changes and modifications all fall within the protection scope of the present application.

Claims

1. A core engine nozzle comprising a cowl body and a nozzle outer barrel, characterized by, The core engine nozzle further comprises a tail cone sleeve, the tail cone sleeve is sleeved on the outer surface of the tail cone body, the outer surface of the tail cone sleeve is composed of a line I, a line II and a joint point, the line I is tangent to the outer surface of the tail cone body, the line I and the line II are smoothly tangent and connected through the joint point, and the joint point and an end wall of the nozzle outer cylinder form a throat section of the core engine nozzle.

2. The core engine nozzle of claim 1, wherein, The core engine nozzle further comprises a tail cone sleeve accessory, the tail cone sleeve accessory is sleeved on the outer surface of the tail cone sleeve, and the outer surface of the tail cone sleeve accessory is composed of the line I, the line II and the joint point.

3. The core engine nozzle of claim 2, wherein, The tail cone sleeve accessory is selected from any one of a sleeve accessory assembly composed of tail cone sleeve accessories of different specifications.

4. The core engine nozzle of claim 1, wherein, The line I is generated by a cubic Bezier curve equation, and the line II is generated by a characteristic line method.

5. The core engine nozzle of claim 1 wherein, The inner side of the tail cone sleeve is fitted to the outer surface of the tail cone body.

6. The core engine nozzle of claim 1 wherein, The tail cone sleeve is detachably connected with the tail cone body.

7. The core engine nozzle of claim 6 wherein, The tail cone sleeve is selected from any one of a sleeve assembly composed of tail cone sleeves of different specifications.

8. The core engine nozzle of any one of claims 1-7, wherein, The end of the tail cone body is aligned with the other end of the line II relative to the joint point.

9. The core engine nozzle of claim 8 wherein, The end of the tail cone body is provided with an anti-backflow baffle, an end wall of the anti-backflow baffle is abutted to the inner surface of the tail cone body, the anti-backflow baffle is provided with an exhaust portion, and the exhaust portion penetrates through the anti-backflow baffle.

10. The core engine nozzle of claim 9, wherein, The exhaust portion is a plurality of exhaust grooves in an axisymmetric array.

11. The core engine nozzle of claim 10 wherein, The exhaust portion is located at a position of 50% to 80% of the height in the radial direction of the anti-backflow baffle.

12. The core engine nozzle of claim 10, wherein, The inner side of the anti-backflow baffle is provided with a flow guide cone, the bottom of the flow guide cone is fixedly connected to the anti-backflow baffle and located inside the array composed of the plurality of exhaust grooves, and the cone tip of the flow guide cone extends from the anti-backflow baffle to the inner cavity of the tail cone body.

13. A core machine characterized by The core engine nozzle comprises the core engine nozzle according to any one of claims 1 to 12.

14. An aeroengine characterised in that, The core engine comprises the core engine according to claim 13.

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