A flexible connection structure for large-size thin-wall exhaust diffuser

Abstract

The invention relates to the field of aerial environment simulation test equipment for aircraft engines, and discloses a flexible connection structure of a large-size thin-walled exhaust diffuser, comprising an inner cylinder, an outer cylinder, and a first water guide plate, wherein the inner cylinder comprises a straight section inner shell and a conical section inner shell arranged in sequence along an airflow direction, and the small-diameter end of the conical section inner shell is smoothly connected to the outlet end of the straight section inner shell; a first flexible connection component is used to connect a connection plate and a straight section outer shell, and the first flexible connection component is fixedly connected to the first water guide plate, the first flexible connection component can not only absorb the axial thermal displacement difference between the straight section and the conical section of the inner cylinder and the outer cylinder, but also because the first water guide plate is fixedly connected to the first flexible connection component, the higher thermal deformation of the straight section inner shell is transmitted to the first flexible connection component, so as to absorb the radial thermal displacement difference between the straight section inner shell and the straight section outer shell of the exhaust diffuser, thereby facilitating the coordination of the thermal deformation of the inner cylinder and the outer cylinder of the exhaust diffuser, and ensuring the safety of the test.

Description

Technical Field

[0001] The invention relates to the field of aviation engine air environment simulation test equipment and discloses a large-size thin-wall exhaust diffuser flexible connection structure. Background Art

[0002] The exhaust diffuser is an important device for the air environment simulation test of the engine exhaust environment. It is mainly used to collect the exhaust gas from the engine and make full use of the engine exhaust impulse to achieve the two-stream injection in the air environment simulation cabin, and convert the kinetic energy of the engine exhaust into pressure energy, so as to reduce the burden of the exhaust system and simplify the exhaust system structure.

[0003] The exhaust diffuser works in a high temperature environment. The gas with a temperature of up to 1600~1900℃ directly contacts the inner wall of the exhaust diffuser. To protect the diffuser, the exhaust diffuser structure is generally a double-layer water jacket. From the perspective of heat exchange, the shell thickness needs to be as thin as possible; but the inner cylinder is subjected to a large external pressure. In order to prevent the external pressure from becoming unstable, sufficient rigidity is required, and there is a conflict between the two.

[0004] The conventional solution is to weld the inner and outer tubes together through reinforcing ribs to increase the rigidity. However, the exhaust diffuser gas temperature and high heat flux density lead to high wall temperature. This method cannot meet the strength requirements and brings safety risks to the test. Summary of the invention

[0005] The purpose of the present invention is to provide a large-size thin-wall exhaust diffuser flexible connection structure, which is conducive to coordinating the thermal deformation of the inner cylinder and the outer cylinder of the exhaust diffuser, thereby increasing the service life of the exhaust diffuser and ensuring test safety.

[0006] In order to achieve the above technical effects, the technical solution adopted by the present invention is:

[0007] A large-size thin-wall exhaust diffuser flexible connection structure, comprising:

[0008] An inner cylinder, the inner cylinder comprising a straight section inner shell and a conical section inner shell arranged in sequence along the airflow direction, the small-diameter end of the conical section inner shell being smoothly connected to the outlet end of the straight section inner shell;

[0009] A first water guide plate, the first water guide plate being fixed to the outer wall of the straight section inner shell;

[0010] The outer cylinder comprises a straight section outer shell, a connecting plate and a conical section outer shell. The straight section outer shell is sleeved on the outer periphery of the straight section inner shell, and the conical section outer shell is sleeved on the outer periphery of the conical section inner shell. One end of the connecting plate is connected to the conical section outer shell.

[0011] The first flexible connection component is used to connect the connection plate and the straight section outer shell, and the first flexible connection component is fixedly connected to the first water guide plate.

[0012] Furthermore, the first flexible connection assembly includes a mounting tube and two flexible connectors, the mounting tube is coaxially arranged with the outer cylinder; the two flexible connectors are respectively connected to the axial sides of the mounting tube, and are used to connect the mounting tube and the straight section outer shell into a cylindrical structure; the mounting tube and the first water guide plate are fixedly connected via a ring plate.

[0013] Furthermore, there are a plurality of first water guide plates, and the plurality of first water guide plates are evenly distributed in an circumferential direction on the outer circumference of the straight section inner shell.

[0014] Furthermore, a second water guide plate is provided between the cone section inner shell and the cone section outer shell, and there are a plurality of second water guide plates, which are evenly distributed in annular direction on the outer circumference of the cone section inner shell.

[0015] Furthermore, the connecting plate is connected to the cone section outer shell through a second flexible connection component, the second water guide plate is fixedly connected to the second flexible connection component, and the second water guide plate is fixed to the outer wall of the cone section inner shell on one side close to the cone section inner shell.

[0016] Furthermore, the inner wall of the cone section outer shell is provided with a plurality of circumferentially evenly distributed protrusions, each of which protrudes radially inwardly along the cone section outer shell, and the straight section outer shell is provided with a plurality of thrust plates that can abut against the protrusions.

[0017] Furthermore, a mounting opening is provided on the outer cylinder at an axial position corresponding to the thrust plate, and a cover plate which can cover the mounting hole is detachably provided at the mounting opening.

[0018] Furthermore, a plurality of support plates are evenly installed annularly on the outer wall of the straight section inner shell, one end of each support plate is fixed on the outer wall of the straight section inner shell near the straight section outlet end, and the other end of each support plate is gap-matched with the inner wall of the conical section outer shell.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention arranges the first flexible connection component on the straight section outer shell, which can not only absorb the axial thermal displacement difference between the straight section and the tapered section of the inner cylinder and the outer cylinder, but also because the first water guide plate is fixedly connected to the first flexible connection component, the higher thermal deformation of the straight section inner shell is transferred to the first flexible connection component, so as to absorb the radial thermal displacement difference between the straight section inner shell and the straight section outer shell of the exhaust diffuser, thereby facilitating the coordination of the thermal deformation of the inner cylinder and the outer cylinder of the exhaust diffuser, prolonging the service life of the exhaust diffuser, and ensuring the safety of the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the flexible connection structure of a large-sized thin-wall exhaust diffuser in an embodiment;

[0022] Figure 2 It is a schematic diagram of the cross-sectional structure of the straight section inner shell and the ring plate in the embodiment;

[0023] Figure 3 is a schematic structural diagram of a first flexible connection assembly in an embodiment;

[0024] Among them, 1. straight section inner shell; 2. conical section inner shell; 3. first water guide plate; 4. straight section outer shell; 5. connecting plate; 6. conical section outer shell; 7. first flexible connection component; 701. mounting tube; 702. flexible connector; 8. ring plate; 9. second water guide plate; 10. second flexible connection component; 11. bump; 12. thrust plate; 13. cover plate; 14. support plate. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below in conjunction with the embodiments and drawings. However, it should not be understood that the scope of the above subject matter of the present invention is limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

[0026] Example

[0027] See also Figure 1-Figure 3 , a large-size thin-wall exhaust diffuser flexible connection structure, comprising:

[0028] An inner cylinder, the inner cylinder comprising a straight section inner shell 1 and a conical section inner shell 2 arranged in sequence along the airflow direction, the small-diameter end of the conical section inner shell 2 being smoothly connected to the outlet end of the straight section inner shell 1;

[0029] A first water guide plate 3, wherein the first water guide plate 3 is fixed to the outer wall of the straight inner shell 1;

[0030] The outer cylinder comprises a straight section outer shell 4, a connecting plate 5 and a conical section outer shell 6. The straight section outer shell 4 is sleeved on the outer periphery of the straight section inner shell 1, and the conical section outer shell 6 is sleeved on the outer periphery of the conical section inner shell 2; one end of the connecting plate 5 is connected to the conical section outer shell 6;

[0031] The first flexible connection component 7 is used to connect the connection plate 5 and the straight section outer shell 4 , and the first flexible connection component 7 is fixedly connected to the first water guide plate 3 .

[0032] In this embodiment, the inner side of the inner cylinder of the exhaust diffuser is in contact with the high-temperature combustion gas in the working state, and the inner cylinder and the outer cylinder are provided with a cooling medium channel, and the outer wall of the inner cylinder is in contact with the cooling medium, and the heat is taken away by the cooling medium. The first water guide plate 3 is arranged at intervals along the circumference in the cooling medium channel, and plays the role of diversion and guidance, ensuring that the cooling medium channel flows evenly and stably in the axial direction; by arranging the first flexible connection component 7 on the straight section outer shell 4, not only the axial thermal displacement difference between the straight section and the tapered section of the inner cylinder, the outer cylinder can be absorbed, but also because the first water guide plate 3 is fixedly connected to the first flexible connection component 7, the higher thermal deformation of the straight section inner shell 1 is transferred to the first flexible connection component 7, so as to absorb the radial thermal displacement difference between the straight section inner shell 1 and the straight section outer shell 4 of the exhaust diffuser, which is conducive to coordinating the thermal deformation of the inner cylinder and the outer cylinder of the exhaust diffuser, improving the service life of the exhaust diffuser, and ensuring the safety of the test.

[0033] In this embodiment, the first flexible connection component 7 includes a mounting tube 701 and two flexible connectors 702. The mounting tube 701 is coaxially arranged with the outer cylinder; the two flexible connectors 702 are respectively connected to the axial sides of the mounting tube 701, and are used to connect the mounting tube 701 and the straight section outer shell 4 into a cylindrical structure; the mounting tube 701 and the first water guide plate 3 are fixedly connected through the ring plate 8. By adopting the structure combining the first flexible connection component 7 and the ring plate 8, on the basis of achieving the coordination of the thermal deformation of the inner cylinder and the outer cylinder of the exhaust diffuser, the ring plate 8 is used as a reinforcement ring to increase the annular stiffness of the inner cylinder to resist the instability of external pressure, thereby solving the problem of the contradiction between the instability of external pressure and the coordination of deformation, and helping to alleviate the problem of impact vibration.

[0034] The cooling medium used in this embodiment is water, and other cooling media are also applicable to the present invention. In this embodiment, there are multiple first water guide plates 3, and the multiple first water guide plates 3 are evenly distributed around the outer periphery of the straight section inner shell 1, which can ensure smooth water flow and solve the problem of excessive pressure loss.

[0035] In this embodiment, a second water guide plate 9 is further provided between the cone section inner shell 2 and the cone section outer shell 6, and the number of the second water guide plates 9 is multiple, and the multiple second water guide plates 9 are evenly distributed in the circumference of the cone section inner shell 2. The second water guide plate 9 forms a water passage between the cone section inner shell 2 and the cone section outer shell 6 to ensure smooth water flow.

[0036] Similar to the first water guide plate 3, the connection plate 5 and the cone section outer shell 6 in this embodiment are connected by a second flexible connection component 10, the second water guide plate 9 is fixedly connected to the second flexible connection component 10, and the second water guide plate 9 is fixed to the outer wall of the cone section inner shell 2 on the side close to the cone section inner shell 2. It is possible to absorb the radial thermal displacement difference between the exhaust diffuser cone section inner shell 2 and the cone section outer shell 6, which is further conducive to coordinating the thermal deformation of the exhaust diffuser inner cylinder and outer cylinder.

[0037] In this embodiment, a plurality of support plates 14 are evenly installed in the annular direction on the outer wall of the straight section inner shell 1, one end of each support plate 14 is fixed to the outer wall of the straight section inner shell 1 near the straight section outlet end, and the other end of each support plate 14 is clearance-matched with the inner wall of the conical section outer shell 6. The support plate 14 is used to support the outer shell of the expansion and discharge, and also plays a centering role. Moreover, since the clearance is set with the inner wall of the conical section outer shell 6, the conical section outer shell 6 is allowed to have a certain axial displacement, avoiding the problem that the conical section inner shell 2 is easily deformed when the thermal deformation of the conical section inner shell 2 and the conical section outer shell 6 is inconsistent.

[0038] In this embodiment, the inner wall of the cone section outer shell 6 is provided with a plurality of circumferentially evenly distributed protrusions 11, each of which protrudes radially inwardly along the cone section outer shell, and the straight section outer shell is provided with a plurality of thrust plates 12 that can abut against the protrusions 11. The thrust plates 12 cooperate with the protrusions 11 to ensure the normal circulation of the cooling medium while also bearing the thrust generated by the changes in the cone section flow area and the shell stiffness, thereby avoiding the problem of the second flexible connection component 10 being torn by force.

[0039] In this embodiment, the outer cylinder is provided with a mounting opening at an axial position corresponding to the thrust plate 12, and a cover plate 13 that can cover the mounting hole is detachably provided at the mounting opening. When assembling the straight section of the exhaust diffuser structure of this embodiment, the thrust plate 12 and the straight section inner shell 1 can be welded through the mounting opening, and the protrusion 11 and the outer shell can be welded. After welding, the mounting opening is covered by the cover plate 13, which is convenient for assembly and can ensure the integrity of the cooling medium channel.

[0040] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A flexible connection structure for a large-size thin-wall exhaust diffuser, characterized in that: include: An inner cylinder, the inner cylinder comprising a straight section inner shell and a conical section inner shell arranged in sequence along the airflow direction, the small-diameter end of the conical section inner shell being smoothly connected to the outlet end of the straight section inner shell; A first water guide plate, the first water guide plate being fixed to the outer wall of the straight section inner shell; The outer cylinder comprises a straight section outer shell, a connecting plate and a conical section outer shell. The straight section outer shell is sleeved on the outer periphery of the straight section inner shell, and the conical section outer shell is sleeved on the outer periphery of the conical section inner shell. One end of the connecting plate is connected to the conical section outer shell. The first flexible connection component is used to connect the connection plate and the straight section outer shell, and the first flexible connection component is fixedly connected to the first water guide plate.

2. The large-size thin-wall exhaust diffuser flexible connection structure according to claim 1 is characterized in that: The first flexible connection assembly includes a mounting tube and two flexible connectors, wherein the mounting tube is coaxially arranged with the outer cylinder; the two flexible connectors are respectively connected to the axial sides of the mounting tube, and are used to connect the mounting tube and the straight section outer shell into a cylindrical structure; the mounting tube and the first water guide plate are fixedly connected via a ring plate.

3. The large-size thin-wall exhaust diffuser flexible connection structure according to claim 1, characterized in that: There are multiple first water guide plates, and the multiple first water guide plates are evenly distributed around the outer periphery of the straight section inner shell.

4. The large-size thin-wall exhaust diffuser flexible connection structure according to claim 1, characterized in that: A second water guide plate is further arranged between the cone section inner shell and the cone section outer shell. There are a plurality of second water guide plates, which are evenly distributed around the outer periphery of the cone section inner shell.

5. The large-size thin-wall exhaust diffuser flexible connection structure according to claim 4, characterized in that: The connecting plate is connected to the cone section outer shell through a second flexible connection component, the second water guide plate is fixedly connected to the second flexible connection component, and the second water guide plate is fixed to the outer wall of the cone section inner shell on one side close to the cone section inner shell.

6. The large-size thin-wall exhaust diffuser flexible connection structure according to claim 5, characterized in that: The inner wall of the cone section outer shell is provided with a plurality of circumferentially evenly distributed protrusions, each of which protrudes radially inwardly along the cone section outer shell, and the straight section outer shell is provided with a plurality of thrust plates that can abut against the protrusions.

7. The flexible connection structure of a large-size thin-wall exhaust diffuser according to claim 6, characterized in that: The outer cylinder is provided with a mounting opening at an axial position corresponding to the thrust plate, and a cover plate capable of covering the mounting hole is detachably provided at the mounting opening.

8. The large-size thin-wall exhaust diffuser flexible connection structure according to claim 1, characterized in that: The outer wall of the straight section inner shell is also circumferentially evenly installed with a plurality of support plates, one end of each support plate is fixed on the outer wall of the straight section inner shell near the straight section outlet end, and the other end of each support plate is gap-matched with the inner wall of the conical section outer shell.

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