An elastic flange device for mounting a ceramic matrix composite mixer

Abstract

The application relates to an elastic flange device for mounting a ceramic matrix composite material mixer, which solves the technical problems of thermal adaptation and poor vibration resistance of the ceramic matrix composite material mixer when the ceramic matrix composite material mixer is connected with a metal casing. The device comprises a support ring, an inner lining ring and mounting screws; the support ring is a rotary body structure, and the support ring comprises a casing mounting flange and a mixer mounting flange fixed on the casing mounting flange; the mixer mounting flange comprises a plurality of independent elastic connecting pieces, and gaps exist between adjacent elastic connecting pieces; the elastic connecting pieces are provided with mixer mounting holes; the inner lining ring is provided with mixer connecting holes corresponding to the mixer mounting holes one by one; and the mounting screws are threadedly connected with the corresponding mixer mounting holes and mixer connecting holes. The application solves the thermal adaptation problem between the metal and the composite material, and avoids damage or failure of the ceramic composite material mixer in a long-term vibration environment.

Description

Technical Field

[0001] This invention relates to an installation device for a ceramic matrix composite mixer, and more specifically to a flexible flange device for installing a ceramic matrix composite mixer. Background Technology

[0002] A mixer is a relatively complex three-dimensional annular cylindrical component located between the internal and external bypass airflow of an engine, and its structure generally has complex curved surface features with multiple lobes. With the development of high-performance engine technology, the overall engine design has placed higher demands on the weight, operating temperature, and structural stiffness of mixer components.

[0003] Currently, the iron-based, nickel-based, or titanium-based alloys used in mixers are no longer sufficient to meet the structural weight reduction and noise reduction requirements necessary for the safe and reliable operation of advanced engines. Ceramic matrix composites, as a thermal-structural-functional integrated material with the advantages of various materials such as low density, high temperature resistance, oxidation resistance, corrosion resistance, high toughness, and high stiffness, have been tested and verified in engines.

[0004] In aero-engine exhaust systems, the mixer is typically mounted on the inner casing, which is still made of metal. The exhaust system withstands a wide range of temperature variations; currently, the mainstream exhaust gas temperature in engine tailpipes is 550–850°C, and under afterburner conditions, the temperature can reach 1200°C or even higher. Furthermore, when aircraft require improved maneuverability, core engine components often need to withstand multiple and rapid temperature increases and decreases. Because ceramic matrix composites and metals possess two drastically different material properties and characteristics, especially the difference in their coefficients of thermal expansion, the mounting flange structure between the ceramic matrix composite mixer and the inner casing should be designed to allow for sufficient expansion and contraction space to release stress, preventing excessive deformation that could lead to damage or failure.

[0005] Furthermore, during engine operation, engine components are also in a complex environment subject to multiple vibration couplings. Currently, ceramic matrix composite mixers mostly use rigid flanges for installation and fixation. However, unlike metal materials with better homogeneity, ceramic matrix composites, due to the influence of their manufacturing process, cannot achieve complete density and homogeneity. At the same time, although the fibers, interfaces, and matrix in the material complement each other, they still cannot overcome their poor vibration resistance. Therefore, vibration reduction and absorption effects should also be considered when designing the flange structure for installing ceramic matrix composite mixers.

[0006] The key design consideration for the flange structure of the ceramic matrix composite mixer is that the flange structure needs to address the thermal compatibility issue between the two materials: the metal casing and the ceramic matrix composite mixer. At the same time, the flange should also serve as an elastic support to reduce vibrations from inside the engine. Summary of the Invention

[0007] To address the technical problems of thermal compatibility and poor vibration resistance of ceramic matrix composites when connecting them to metal casings, this invention proposes an elastic flange device for installing ceramic matrix composite mixers.

[0008] The technical solution provided by this invention is as follows:

[0009] A flexible flange device for mounting a ceramic matrix composite mixer is characterized by comprising a support ring, an inner liner ring, and mounting screws.

[0010] The support ring is a rotating body structure, and the support ring includes a casing mounting flange and a mixer mounting flange fixed to the casing mounting flange;

[0011] The mixer mounting flange includes multiple independent elastic connecting pieces with gaps between adjacent elastic connecting pieces; each elastic connecting piece is provided with a mixer mounting hole, which is located at the end of the elastic connecting piece away from the casing mounting flange;

[0012] The inner liner ring is provided with mixer connection holes that correspond one-to-one with each mixer mounting hole.

[0013] The mounting screws are threaded into the corresponding mixer mounting holes and mixer connection holes to fix the ceramic matrix composite material mixer between the support ring and the inner liner ring.

[0014] Furthermore, the support ring also includes a lower baffle; the lower baffle is disposed on the housing mounting flange and protrudes inward in an annular shape;

[0015] There is a first gap between the lower baffle and the end of the inner liner ring, the first gap having an axial upward dimension of 2-3 mm; there is a second gap between the lower baffle and the end of the ceramic matrix composite material mixer, the second gap having a dimension of 2-3 mm.

[0016] If the first gap is too large, it will cause loss of airflow and pressure; if the first gap is too small, it will affect the elasticity of the elastic flange structure. The second gap is used to ensure that the ceramic matrix composite mixer can freely deform and release stress in the axial direction during thermal expansion and contraction.

[0017] Furthermore, the elastic connecting pieces are evenly arranged circumferentially, and each elastic connecting piece has at least one hollow hole.

[0018] Furthermore, the number of elastic connecting pieces is 15; the hollow holes are square holes, and the number of hollow holes on any one of the elastic connecting pieces is 3.

[0019] Furthermore, the elastic connecting piece has an inwardly protruding boss on the side away from the casing mounting flange, and the mixer mounting hole is located on the boss.

[0020] Furthermore, the boss is arranged in an arc shape along the circumference for contacting the outer surface of the ceramic matrix composite material mixer.

[0021] Furthermore, the mixer connection hole is located on the side of the inner liner ring away from the casing mounting flange.

[0022] Furthermore, the screw head of the mounting screw is inside the inner liner ring.

[0023] Furthermore, the materials of the support ring, the inner liner ring, and the mounting screw are one or more of iron-based high-temperature alloys, nickel-based high-temperature alloys, cobalt-based high-temperature alloys, and titanium alloys.

[0024] The beneficial effects of this invention are:

[0025] 1. The elastic flange device for installing ceramic matrix composite mixers proposed in this invention adopts a certain number of elastic connecting pieces evenly distributed along the circumference, and achieves elastic connection of the mixer mounting flange by setting gaps between adjacent elastic connecting pieces. Unlike the previous rigid connection, the elastic connection can effectively suppress the cracking of ceramic matrix composite mixers in a multi-vibration coupling environment, which may lead to damage or failure of components, thereby extending the service life of ceramic matrix composite mixers.

[0026] 2. The elastic flange device for installing the ceramic matrix composite mixer proposed in this invention adopts the form of elastic connecting plates evenly arranged in the circumferential direction. The elastic deformation of the elastic connecting plates in the radial direction can meet the requirements of the ceramic matrix composite mixer to deform radially and release internal stress in a wide temperature range service environment. In addition, the gap between the air inlet end face of the ceramic matrix composite mixer and the lower baffle can meet the requirements of the ceramic matrix composite mixer to deform axially and release internal stress, thus effectively solving the thermal compatibility problem between the metal casing and the ceramic matrix composite mixer.

[0027] 3. The elastic flange device for installing ceramic matrix composite material mixers proposed in this invention can achieve a structural weight reduction of more than 24% compared with the traditional rigid flange structure. Attached Figure Description

[0028] Figure 1 This is an exploded view of an embodiment of the elastic flange device for installing a ceramic matrix composite material mixer according to the present invention;

[0029] Figure 2 This is a schematic diagram of an assembly of an embodiment of the elastic flange device for installing a ceramic matrix composite material mixer according to the present invention;

[0030] Figure 3 This is a schematic diagram of the support ring structure in an embodiment of the present invention;

[0031] Figure 4 This is a schematic diagram of the inner liner ring structure in an embodiment of the present invention;

[0032] Figure 5 This is a schematic diagram of the structure of the ceramic matrix composite mixer installed in an embodiment of the present invention.

[0033] The attached figures are labeled as follows:

[0034] 1-Support ring, 2-Inner liner ring, 3-Mounting screw, 4-Ceramic matrix composite mixer, 11-Casing mounting hole, 12-Elastic connecting piece, 13-Mixer mounting hole, 14-Boss, 15-Hollow hole, 16-Lower baffle, 21-Mixer connection hole. Detailed Implementation

[0035] See Figures 1-5 This embodiment provides an elastic flange device for installing a ceramic matrix composite material mixer. The elastic flange device includes a support ring 1, an inner liner ring 2, and mounting screws 3. The materials of the support ring 1, the inner liner ring 2, and the mounting screws 3 are one or more of iron-based high-temperature alloys, nickel-based high-temperature alloys, cobalt-based high-temperature alloys, and titanium alloys.

[0036] The support ring 1 is a rotating structure, including a casing mounting flange and a mixer mounting flange fixed to the casing mounting flange; the casing mounting flange is provided with a casing mounting hole 11 for connection with the metal inner casing; the support ring 1 also includes a lower baffle 16; the lower baffle 16 is located on the casing mounting flange and protrudes inward in an annular shape; there is a first gap between the lower baffle 16 and the end of the inner liner ring 2, the first gap being 2-3mm. The first gap should not be too large or too small. If it is too large, it will cause loss of airflow and pressure; if it is too small, it will affect the elasticity of the elastic flange structure; there is a second gap between the lower baffle 16 and the end of the ceramic matrix composite mixer 4, the second gap being 2-3mm. The second gap is used to ensure that the ceramic matrix composite mixer can freely deform and release stress in the axial direction during thermal expansion and contraction.

[0037] The mixer mounting flange includes multiple independent elastic connecting pieces 12, with gaps between adjacent elastic connecting pieces 12; the elastic connecting pieces 12 are evenly arranged circumferentially, and each elastic connecting piece 12 has at least one hollow hole 15. In this embodiment, the number of elastic connecting pieces 12 is 15; the hollow holes 15 are square holes, and the number of hollow holes 15 on any elastic connecting piece 12 is 3; it can be understood that, depending on the material used, simulation algorithms can be used to select various combinations of the gaps between adjacent elastic connecting pieces 12 and the number and shape of the hollow holes 15 on the elastic connecting pieces 12.

[0038] The elastic connecting piece 12 is provided with a mixer mounting hole 13, which is located at the end of the elastic connecting piece 12 away from the casing mounting flange. Specifically, the side of the elastic connecting piece 12 away from the casing mounting flange is provided with an inwardly protruding boss 14, and the mixer mounting hole 13 is located on the boss 14. The boss 14 is arranged in an arc shape along the circumference and is used to abut against the outer surface of the ceramic matrix composite mixer 4.

[0039] The inner liner ring 2 is provided with mixer connection holes 21 corresponding to each mixer mounting hole 13; the mixer connection holes 21 are located on the side of the inner liner ring 2 away from the casing mounting flange.

[0040] The mounting screw 3 is threaded to the corresponding mixer mounting hole 13 and mixer connection hole 21 to fix the ceramic matrix composite mixer 4 between the support ring 1 and the inner liner ring 2. Specifically, the screw head of the mounting screw 3 is inside the inner liner ring 2.

[0041] The method of using the above-mentioned flexible flange device includes the following steps:

[0042] (1) Slide the inner liner ring 2 along the inner wall of the air inlet end of the ceramic matrix composite material mixer 4, and align the mounting holes by adjusting the axial and circumferential relative positions between the two.

[0043] (2) Slide one side of the elastic connecting piece 12 of the support ring 1 along the outer wall of the air inlet end of the ceramic matrix composite material mixer 4, and align the holes on the component by adjusting the relative positions of the axial and circumferential directions.

[0044] (3) Screw the mounting screw 3 outward from the inner wall of the inner liner ring 2, through the inner liner ring 2, the ceramic matrix composite mixer 4 and the support ring 1 in sequence, and tighten it.

[0045] This method can solve the thermal compatibility problem between metal and composite materials, and at the same time change the installation method of the mixer from rigid support to elastic support, so as to avoid damage or failure of the ceramic matrix composite material mixer 4 in the long-term vibration environment.

Claims

1. An elastomeric flange device for mounting a ceramic matrix composite mixer, characterized by: The support ring, the inner lining ring and the mounting screw are included; The support ring is a rotary body structure, and the support ring includes a casing mounting flange and a mixer mounting flange fixed to the casing mounting flange; The mixer mounting flange includes a plurality of independent elastic connecting pieces, and gaps are arranged between adjacent elastic connecting pieces; the elastic connecting pieces are provided with mixer mounting holes, and the mixer mounting holes are arranged at one end of the elastic connecting pieces away from the casing mounting flange; The inner lining ring is provided with mixer connecting holes corresponding to the mixer mounting holes one by one; The mounting screw is in threaded connection with the corresponding mixer mounting hole and the mixer connecting hole, and is used for fixing the ceramic matrix composite mixer between the support ring and the inner lining ring; The support ring further includes a lower baffle; the lower baffle is arranged on the casing mounting flange and protrudes inward in a ring shape; The lower baffle and the end portion of the inner lining ring have a first gap, and the first gap is 2-3 mm; The lower baffle and the end portion of the ceramic matrix composite mixer have a second gap, and the second gap is 2-3 mm; The elastic connecting pieces are uniformly arranged in the circumferential direction, and at least one hollow hole is arranged on the elastic connecting pieces.

2. The elastic flange device for mounting the ceramic matrix composite mixer according to claim 1, wherein: The number of the elastic connecting pieces is 15; The hollow holes are square holes, and the number of the hollow holes on any one of the elastic connecting pieces is 3.

3. The elastic flange device for mounting the ceramic matrix composite mixer according to claim 1 or 2, wherein: One side of the elastic connecting piece away from the casing mounting flange is provided with a protruding boss inward, and the mixer mounting hole is arranged on the boss.

4. The elastic flange device for mounting the ceramic matrix composite mixer according to claim 3, wherein: The boss is arranged in an arc-shaped strip in the circumferential direction, and is used for abutting against the outer side surface of the ceramic matrix composite mixer.

5. The elastic flange device for mounting the ceramic matrix composite mixer according to claim 4, wherein: The mixer connecting hole is arranged on one side of the inner lining ring away from the casing mounting flange.

6. The elastic flange device for mounting the ceramic matrix composite mixer according to claim 5, wherein: The screw head of the mounting screw is on the inner side of the inner lining ring.

7. The elastic flange device for mounting the ceramic matrix composite mixer according to claim 6, wherein: The materials of the support ring, the inner lining ring and the mounting screw are one or more of iron-based high-temperature alloy, nickel-based high-temperature alloy, cobalt-based high-temperature alloy and titanium alloy.

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