A partition nozzle bushing and a rocket engine

Abstract

The present invention relates to a diaphragm nozzle bushing and a rocket engine, and relates to the field of rocket engines. The side wall of the bushing body has a plurality of bushing holes, and the bushing body has a plurality of mounting sleeve holes that penetrate through its two axial ends. The bushing body includes an annular bushing and a radial bushing, and the annular bushing is an annular shell, and the radial bushing is a rectangular shell. There are a plurality of radial bushings, and the plurality of radial bushings are arranged at intervals along the circumference of the annular bushing and fixedly connected to the annular bushing, and each radial bushing is arranged radially along the annular bushing. The diaphragm nozzle bushing can suppress the instability of high-frequency combustion in the combustion chamber without changing the original design of the engine, and has the advantages of compact structure, simple manufacturing, light weight, and convenient installation, and basically does not interfere with the flow field in the combustion chamber.

Description

Technical Field

[0001] The invention relates to the field of rocket engines, and in particular to a partition nozzle bushing and a rocket engine. Background Art

[0002] The instantaneous heat release power of the thrust chamber of a liquid rocket engine can generally reach several thousand MW, while the volume of the combustion chamber is usually less than 0.5m 2 , the energy release density is extremely high, which can easily induce high-frequency combustion instability. Such problems usually cause large vibrations in the thrust chamber, which may induce structural damage and is one of the key issues faced by model development. During the engine startup process, due to the small nozzle pressure drop, the component mixture accumulates in the dead zone or combustion chamber cavity, and its combustion may generate pulses and cause high-frequency combustion instability. The excitation pulse has a certain randomness, and sometimes the finalized engine will also experience high-frequency combustion instability during startup. The formation mechanism of high-frequency combustion instability is very complex, but its essence is the result of the coupling of the combustion heat release process and the combustion chamber acoustic process. Therefore, the control of high-frequency combustion instability generally reduces the oscillation amplitude from two aspects: reducing the input of excitation energy and increasing the dissipation of the disturbance propagation process, thereby improving the stability of the thrust chamber. Based on this, there are many means in engineering to suppress high-frequency combustion instability. Traditional means of suppressing unstable combustion include: adjusting the spatiotemporal distribution of the injector combustion response, setting up resonant absorbers such as baffles, acoustic cavities, and acoustic liners, etc. However, for a relatively mature model, if the design of the injector or baffle is changed, it may lead to the failure of the rich test data of the engine and the reduction of the rated state performance and hot wall cooling performance of the engine; and the resonant absorber is usually tuned to the rated operating conditions, so they are in a non-tuned state at startup and do not work. Sudden engine startup instability problems may cause the project to stagnate, and researchers may need to spend a lot of time, energy and money to solve them, which will affect the progress of the project. In the most serious case, the R&D team may be forced to redesign the combustion chamber.

[0003] In order to solve the problem of high-frequency combustion instability during the engine startup phase, the existing method is to set radial or longitudinal ablative anti-pulsation baffles (ribs) on the side walls of the combustion chamber to suppress longitudinal and tangential instabilities respectively. The materials are generally felt-type sound-absorbing materials. However, the ablative baffles occupy part of the volume of the combustion zone of the combustion chamber, which will interfere with the combustion flow field and affect the engine's starting process. At the same time, the longitudinal ribs and the liquid rocket engine nozzle baffles have similar mechanisms in suppressing oscillations. When the baffles are already installed, the ablative baffles do not improve the stability much, so the applicability of the ablative baffles is not widespread.

[0004] In summary, liquid rocket engines may experience high-frequency combustion instability during the starting process, which may affect the engine performance or structure. Due to the randomness of the excitation pulse during the starting process, some mature engine models will also have low-repeatability starting oscillation problems. The project hopes to find a reliable suppression device that is easy to install and will not affect the engine working state, especially the rated operating conditions. However, there are few passive suppression methods that meet the above requirements at this stage. Summary of the invention

[0005] The technical problem to be solved by the present invention is how to enhance the pressure pulsation dissipation under the starting condition of the liquid rocket engine without changing the original design parameters of the engine and without affecting the flow field under the rated operating condition of the engine, so as to suppress the combustion instability when the combustion chamber is started.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: a baffle nozzle bushing, comprising a bushing body, the side wall of the bushing body having a plurality of bushing holes, the bushing body having a plurality of mounting sleeve holes passing through its axial ends, the bushing body comprising an annular bushing and a radial bushing, the annular bushing being an annular shell, the radial bushing being a rectangular shell, the radial bushing being multiple, the multiple radial bushings being arranged at intervals along the circumference of the annular bushing and fixedly connected to the annular bushing, and each of the radial bushings being arranged radially along the annular bushing.

[0007] The beneficial effects of the present invention are as follows: the annular bushing and the radial bushing are mounted on the baffle nozzle through the mounting sleeve holes, and the absorption of the acoustic energy or pressure wave in the combustion chamber during the engine startup process is achieved through the shell structure with multiple bushing holes. The sound wave undergoes Helmholtz resonance in the bushing body, amplifying the thermal viscosity dissipation mechanism of the baffle nozzle gap. In addition, the thermal viscosity of the numerous bushing holes in the bushing body and the vortex shedding formed on the top plane of the bushing holes also cause a large amount of acoustic vortex dissipation of the acoustic energy. After the engine enters the rated operating condition, the bushing body is ablated into gas or separated from the combustion chamber, which does not affect the rated working state.

[0008] The baffle nozzle bushing of this scheme can suppress the instability of high-frequency combustion in the combustion chamber without changing the original design of the engine, and has the advantages of compact structure, simple manufacturing, light weight, and easy installation, and basically does not interfere with the flow field in the combustion chamber.

[0009] Based on the above technical solution, the present invention can also be improved as follows.

[0010] Furthermore, the multiple mounting sleeve holes are divided into an annular liner hole group and multiple radial liner hole groups, the multiple mounting sleeve holes of the annular liner hole group are evenly distributed along the circumference of the annular bushing, the multiple radial liner hole groups correspond one-to-one to the multiple radial bushings, and the multiple mounting sleeve holes of the radial liner hole group are evenly distributed along the length direction of the corresponding radial bushing.

[0011] The beneficial effect of adopting the above further solution is that mounting holes are designed on both the annular bushing and the radial bushing corresponding to the baffle nozzles, so that the bushing body can be directly mounted on multiple baffle nozzles.

[0012] Furthermore, the gap width between the side wall of the mounting sleeve hole of the radial bushing hole group and the corresponding side wall of the radial bushing is b, and the circumferential spacing between the outer walls of two circumferentially adjacent central nozzles is B, b=45%×B.

[0013] The beneficial effect of adopting the above further scheme is that the gap width b will affect the sound absorption performance of the bushing body, but its size is also limited by the installation conditions. The value range of the gap width b can ensure that the bushing body will not block the injection area and affect the combustion process of the combustion chamber.

[0014] Furthermore, the wall thickness of the bushing body is K, K=10%×B, and K≥0.4 mm.

[0015] The beneficial effect of adopting the above further scheme is that the material of the bushing body should be able to withstand the tangential and tensile stresses of the high-speed fluid scouring and not be ablated during the engine starting process. In addition, the product of the ablation of the material cannot be deposited on the wall of the combustion chamber. The ablation time can be changed by adjusting the wall thickness and density of the bushing body, so that the bushing body maintains its basic shape during the working time and ablates quickly after entering the rated working condition. However, the wall thickness of the material is also limited by the maximum stress that the material can withstand and the nozzle spacing. The wall thickness K of the bushing body is preferably 10% of the nozzle circumferential spacing B, but not less than 0.4mm.

[0016] Furthermore, the diameter d of the bushing hole is 0.1-1 mm.

[0017] The beneficial effect of adopting the above further solution is that the diameter d is 0.1-1 mm, which can ensure that the bushing body has good broadband sound absorption performance.

[0018] Furthermore, the bushing height h of the bushing body is 90% of the baffle nozzle height.

[0019] The beneficial effect of adopting the above further solution is that the bushing height h is not greater than the baffle nozzle height, thereby avoiding affecting the normal working state of the baffle nozzle, while having sufficient sound absorption performance.

[0020] Furthermore, the radial bushing includes a radial bushing top plate, a radial bushing bottom plate, a radial bushing side plate and a radial bushing outer end plate. There are two radial bushing side plates, one of which, the radial bushing side plate, the radial bushing top plate, the other radial bushing side plate and the radial bushing bottom plate are connected end to end to form a rectangular tube with open ends. The radial bushing outer end plate is fixedly connected to one end of the rectangular tube and closes the corresponding opening. The other end of the rectangular tube is fixedly connected to the annular bushing.

[0021] The beneficial effect of adopting the above further solution is that the mounting holes form a first mounting hole and a second mounting hole on the top plate and the bottom plate of the diameter liner respectively, which are used to be sleeved on the outside of the partition nozzle. The outer end plate of the diameter liner is used to connect with the inner wall of the combustion chamber.

[0022] The present invention also provides a rocket engine, comprising a plurality of baffle nozzles and baffle nozzle bushings, wherein the plurality of baffle nozzles are arranged in one-to-one correspondence with the plurality of mounting sleeve holes and are inserted into the mounting sleeve holes.

[0023] The beneficial effect is: a baffle nozzle bushing is installed at the baffle nozzle, and the pressure wave forms a Helmholtz resonance in the cavity composed of the bushing body and the baffle nozzle for reflection and absorption. The pressure wave is dissipated through the porous bushing body pores, the thermal viscosity of the baffle nozzle gap and the detached vortex generated at the top of the bushing, thereby absorbing the pressure oscillation during the engine starting process, weakening the thermal and acoustic coupling during the unstable process, and improving the engine starting stability.

[0024] Furthermore, it also includes an injection disk and a combustion chamber, a plurality of baffle nozzles pass through the injection disk and are fixedly connected to the injection disk, the injection disk is fixed in the combustion chamber, one axial end of the bushing body is bonded to the injection disk by an adhesive, and the circumferential side wall of the bushing body is bonded to the inner wall of the combustion chamber by an adhesive.

[0025] The beneficial effect of adopting the above further scheme is: the bushing body is fixed by bonding it to the injection disk and the inner wall of the combustion chamber. Since the temperature of the injection disk is higher than the operating temperature of ordinary adhesives, the van der Waals force between the adhesives is destroyed under high temperature conditions, resulting in a decrease in its maximum shear tensile stress. Therefore, it is recommended to use a high-temperature resistant adhesive as the adhesive material to ensure that the bushing body will not fall off during operation, thereby causing the unstable passive control to fail. In addition, when the engine is switched to rated operating conditions, the injection disk and the combustion chamber wall heat up rapidly, causing the adhesive to fail, causing the unablated part of the bushing structure to fall off directly, avoiding affecting the mixing process of the injector.

[0026] Furthermore, the adhesive is a methacrylate adhesive.

[0027] The beneficial effects of the present invention are as follows: the baffle nozzle bushing for suppressing high-frequency combustion instability during engine starting provided by the present invention can suppress high-frequency combustion instability during engine starting, and the device is compact, has little effect on the flow characteristics during starting, uses ablative materials, does not change the original design parameters of the engine and does not affect the flow field of the engine at rated operating conditions, has the advantages of simple structure, can be directly installed during engine testing, and has strong applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A three-dimensional diagram of the annular bushing of the present invention;

[0029] Figure 2 A three-dimensional diagram of the radial bushing of the present invention;

[0030] Figure 3 It is an assembly diagram of the partition nozzle bushing of the present invention installed in the combustion chamber;

[0031] Figure 4 for Figure 3 Sectional view of assembly drawing;

[0032] Figure 5 It is a schematic diagram of the installation position of the partition nozzle bushing of the present invention.

[0033] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0034] 1. Annular bushing; 2. Radial bushing; 3. First mounting sleeve hole; 4. Partition nozzle; 5. Injection disk; 6. Second mounting sleeve hole; 7. Radial bottom plate; 8. Radial outer end plate; 9. Center nozzle; 10. Bushing hole. DETAILED DESCRIPTION

[0035] The principles and features of the present invention are described below. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0036] like Figure 1-Figure 5 As shown, this embodiment provides a baffle nozzle bushing, including a bushing body, the side wall of the bushing body has a plurality of bushing holes 10, the bushing body has a plurality of mounting sleeve holes penetrating its axial ends, the bushing body is made of ablative material, the bushing body includes an annular bushing 1 and a radial bushing 2, the annular bushing 1 is an annular shell, the radial bushing 2 is a rectangular shell, there are a plurality of radial bushings 2, the plurality of radial bushings 2 are arranged at intervals along the circumferential direction of the annular bushing 1, and are fixedly connected to the annular bushing 1, and each of the radial bushings 2 is radially arranged along the annular bushing 1.

[0037] The annular bushing and radial bushing are mounted on the baffle nozzle through the mounting holes, and the shell structure with multiple bushing holes 10 realizes the absorption of acoustic energy or pressure waves in the combustion chamber during the engine startup process. The sound wave undergoes Helmholtz resonance in the bushing body, amplifying the thermal viscosity dissipation mechanism of the baffle nozzle gap. In addition, the thermal viscosity of the numerous bushing holes 10 in the bushing body and the vortex shedding formed on the top plane of the bushing hole 10 also cause a large amount of acoustic vortex dissipation of the sound energy. After the engine enters the rated operating condition, the bushing body is ablated into gas or separated from the combustion chamber, which does not affect the rated working state.

[0038] The baffle nozzle bushing of this scheme can suppress the instability of high-frequency combustion in the combustion chamber without changing the original design of the engine, and has the advantages of compact structure, simple manufacturing, light weight, and easy installation, and basically does not interfere with the flow field in the combustion chamber.

[0039] Compared with the cylindrical bushings that are sleeved on the outside of the baffle nozzles 4 in a one-to-one correspondence, the cylindrical bushings need to be installed one by one, which is complicated to install and requires a large spacing between the baffle nozzles 4, and cannot be applied to the engine nozzles with compact structures. In this solution, multiple installation sleeve holes are opened on a bushing body, and are sleeved on the outside of all baffle nozzles 4 at the same time, which is more convenient to install and has better dissipation function.

[0040] In one specific example, the material of the bushing body is an ablative material, and the ablative material is a carbon fiber reinforced resin-based composite material or a porous carbon fiber that has certain sound absorption properties. Alternatively, the bushing body of the present invention can also be made of other materials, and the material can be changed to a ceramic material or a high-temperature resistant alloy to avoid ablation and extend the working life of the device, so that the device can continue to work within the service life of the engine. Or the bushing body is bonded to the combustion chamber so that it can fall off from the combustion chamber as a whole at high temperature.

[0041] Specifically, for Figure 5 The distribution form of the baffle nozzle 4 and the central nozzle 9 shown in the figure is that the distribution form of the baffle nozzle 4 is a circle of six diameters, and the sleeve body is composed of an annular sleeve 1 and six radial sleeves 2. If the baffle nozzle 4 is a circle of three diameters or a circle of four diameters, the number of radial sleeves 2 is adjusted to three or four accordingly. If the baffle nozzles 4 are not arranged on the same radius as shown in the legend, but are staggered, the shape of the radial baffle should be adjusted to adapt to the shape of the baffle nozzle and will not affect the normal operation of the central nozzle 9.

[0042] The bushing body is a perforated plate, and the perforated plate can be punched by laser drilling or cutting. The specific processing method can be determined according to the material and shape of the bushing body.

[0043] Specifically, the annular bushing 1 and the radial bushing 2 are connected by welding, and the annular bushing 1 and the radial bushing 2 are assembled, so that the manufacturing and installation of the bushing body are more convenient.

[0044] On the basis of the above technical solution, the multiple mounting sleeve holes are divided into an annular liner hole group and multiple radial liner hole groups. The multiple mounting sleeve holes of the annular liner hole group are evenly distributed along the circumference of the annular bushing 1, the multiple radial liner hole groups correspond one-to-one to the multiple radial bushings 2, and the multiple mounting sleeve holes of the radial liner hole group are evenly distributed along the length direction of the corresponding radial bushing 2.

[0045] Both the annular bushing 1 and the radial bushing 2 are designed with mounting holes corresponding to the baffle nozzles 4 , so that the bushing body can be directly mounted on the multiple baffle nozzles 4 .

[0046] Based on the above technical solution, the gap width between the side wall of the mounting sleeve hole of the radial bushing hole group and the corresponding side wall of the radial bushing 2 is b, and the circumferential spacing between the outer walls of two circumferentially adjacent central nozzles 9 is B, b=45%×B.

[0047] The gap width b will affect the sound absorption performance of the bushing body, but its size is also limited by the installation conditions. The value range of the gap width b can ensure that the bushing body will not block the injection area and affect the combustion process of the combustion chamber.

[0048] Specifically, Figure 5 As shown, the circumferential spacing B refers to the distance between the outer walls of two adjacent central nozzles 9 along the circumferential direction that are close to each other.

[0049] In one specific example, the gap width b is 0.5 mm.

[0050] On the basis of the above technical solution, the wall thickness of the bushing body is K, K=10%×B, and K≥0.4mm.

[0051] The material of the bushing body should be able to withstand the tangential and tensile stresses of high-speed fluid erosion and not be ablated during the engine start-up process. In addition, the product of the ablation of the material cannot be deposited on the combustion chamber wall. The ablation time can be changed by adjusting the wall thickness and density of the bushing body, so that the bushing body maintains its basic shape during the working time and ablates quickly after entering the rated working condition. However, the wall thickness of the material is also limited by the maximum stress that the material can withstand and the nozzle spacing. The wall thickness K of the bushing body is preferably 10% of the nozzle circumferential spacing B, but not less than 0.4mm.

[0052] On the basis of the above technical solution, the diameter d of the bushing hole 10 is 0.1-1 mm.

[0053] The diameter d is 0.1-1 mm, which can ensure that the bushing body has good broadband sound absorption performance.

[0054] Specifically, the resonant frequency of the bushing body is determined by the porosity p, which in turn affects the damping coefficient of the bushing body. In order to obtain the best damping effect for a certain mode vibration type, the porosity p should be between 1% and 3%, and d is the diameter of the bushing hole 10. The formula is:

[0055]

[0056] Where c is the speed of sound, f is the modal frequency of the unstable vibration mode, V is the cavity volume, and S is the back cavity opening area (the sum of the areas of all bushing holes 10), which is obtained by the following formula:

[0057] Sp*A

[0058] Where A is the surface area of ​​the bushing body.

[0059] On the basis of the above technical solution, the bushing height h of the bushing body is 90% of the height of the baffle nozzle 4 .

[0060] The bushing height h is not greater than the baffle nozzle 4 height, so as to avoid affecting the normal working state of the baffle nozzle 4, while having sufficient sound absorption performance.

[0061] In one specific example, the bushing height h is 3.5 mm and the baffle nozzle 4 height is 4 mm.

[0062] On the basis of the above technical solution, the radial bushing 2 includes a radial bushing top plate, a radial bushing bottom plate 7, a radial bushing side plate and a radial bushing outer end plate 8. There are two radial bushing side plates, one of which, the radial bushing side plate, the radial bushing top plate, the other radial bushing side plate and the radial bushing bottom plate 7 are connected end to end to form a rectangular tube with open ends. The radial bushing outer end plate 8 is fixedly connected to one end of the rectangular tube and closes the corresponding opening. The other end of the rectangular tube is fixedly connected to the annular bushing 1.

[0063] The first and second mounting sleeve holes 3 and 6 are formed on the top plate and bottom plate 7 of the liner respectively, and are used to be sleeved on the outside of the partition nozzle 4. The outer end plate 8 of the liner is used to connect with the inner wall of the combustion chamber.

[0064] Specifically, the mounting holes also form a first mounting hole 3 and a second mounting hole 6 on the top plate and the bottom plate of the annular bushing 1 .

[0065] This embodiment also provides a rocket engine, including a plurality of baffle nozzles 4 and a baffle nozzle bushing, wherein the plurality of baffle nozzles 4 are arranged in one-to-one correspondence with the plurality of mounting sleeve holes and are inserted into the mounting sleeve holes.

[0066] A baffle nozzle bushing is installed at the baffle nozzle 4. The pressure wave forms a Helmholtz resonance in the cavity composed of the bushing body and the baffle nozzle for reflection and absorption. The pressure wave is dissipated through the pore dissipation of the porous bushing body, the thermal viscosity of the baffle nozzle gap and the detached vortex generated at the top of the bushing, thereby absorbing the pressure oscillation during the engine starting process, weakening the thermal-acoustic coupling in the unstable process and improving the engine starting stability.

[0067] Optionally, the bushing body is fixed by gluing or welding.

[0068] On the basis of the above scheme, the rocket engine also includes an injection disk 5 and a combustion chamber, a plurality of baffle nozzles 4 pass through the injection disk 5 and are fixedly connected to the injection disk 5, the injection disk 5 is fixed in the combustion chamber, one axial end of the bushing body is bonded to the injection disk 5 by an adhesive, and the circumferential side wall of the bushing body is bonded to the inner wall of the combustion chamber by an adhesive.

[0069] The bushing body is fixed by bonding the bushing body to the injection disk 5 and the inner wall of the combustion chamber. Since the temperature of the injection disk 5 is higher than the operating temperature of ordinary adhesives, the van der Waals force inside the adhesive is destroyed under high temperature conditions, resulting in a decrease in its maximum shear tensile stress. Therefore, it is recommended to use a high-temperature resistant adhesive as the bonding material to ensure that the bushing body will not fall off during operation, thereby causing the unstable passive control to fail. In addition, when the engine is switched to rated operating conditions, the injection disk 5 and the combustion chamber wall heat up rapidly, causing the adhesive to fail, causing the unablated part of the bushing structure to fall off directly, avoiding affecting the mixing process of the injector.

[0070] Specifically, the central nozzle 9 is located at one axial end of the injection disk 5 , and one end of the central nozzle 9 faces the injection disk 5 .

[0071] Based on the above solution, the adhesive is a methacrylate adhesive.

[0072] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "axial", "radial", "circumferential", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0073] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0074] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0075] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0076] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0077] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A baffle nozzle bushing, characterized in that: The invention comprises a bushing body, the side wall of the bushing body has a plurality of bushing holes (10), the bushing body has a plurality of mounting sleeve holes penetrating the two axial ends thereof, the bushing body comprises an annular bushing (1) and a radial bushing (2), the annular bushing (1) is an annular shell, the radial bushing (2) is a rectangular shell, there are a plurality of radial bushings (2), the plurality of radial bushings (2) are arranged at intervals along the circumference of the annular bushing (1) and are fixedly connected to the annular bushing (1), and each radial bushing (2) is arranged radially along the annular bushing (1); The diameter d of the bushing hole (10) is calculated by the following formula: Where c is the speed of sound, f is the modal frequency of the unstable vibration mode, V is the cavity volume, p is the porosity, the value range of p is 1%-3%, S is the back cavity opening area, The back cavity opening area S is obtained by the following formula: Wherein, A is the surface area of ​​the bushing body.

2. A diaphragm nozzle bushing according to claim 1, characterized in that: The plurality of mounting holes are divided into an annular bushing hole group and a plurality of radial bushing hole groups. The plurality of mounting holes of the annular bushing hole group are evenly distributed along the circumference of the annular bushing (1). The plurality of radial bushing hole groups correspond one-to-one to the plurality of radial bushings (2), and the plurality of mounting holes of the radial bushing hole group are evenly distributed along the length direction of the corresponding radial bushing (2).

3. A diaphragm nozzle bushing according to claim 2, characterized in that: The gap width between the side wall of the mounting sleeve hole of the radial bushing hole group and the side wall of the corresponding radial bushing (2) is b, and the circumferential spacing between the outer walls of two circumferentially adjacent central nozzles (9) is B, b=45%×B.

4. A diaphragm nozzle bushing according to claim 3, characterized in that: The wall thickness of the bushing body is K, K=10%×B, and K≥0.4 mm.

5. A diaphragm nozzle bushing according to claim 1, characterized in that: The diameter d of the bushing hole (10) is 0.1-1 mm.

6. A diaphragm nozzle bushing according to claim 1, characterized in that: The bushing height h of the bushing body is 90% of the height of the baffle nozzle (4).

7. A baffle nozzle bushing according to any one of claims 1 to 6, characterized in that: The radial bushing (2) comprises a radial bushing top plate, a radial bushing bottom plate (7), a radial bushing side plate and a radial bushing outer end plate (8), wherein there are two radial bushing side plates, one of which, the radial bushing top plate, the other radial bushing side plate and the radial bushing bottom plate (7) are connected end to end to form a rectangular tube with two open ends, the radial bushing outer end plate (8) is fixedly connected to one end of the rectangular tube and closes the corresponding opening, and the other end of the rectangular tube is fixedly connected to the annular bushing (1).

8. A rocket engine, characterized in that: It comprises a plurality of baffle nozzles (4) and a baffle nozzle bushing as claimed in any one of claims 1 to 7, wherein the plurality of baffle nozzles (4) are arranged in one-to-one correspondence with the plurality of mounting sleeve holes and are inserted into the mounting sleeve holes.

9. A rocket engine according to claim 8, characterized in that: It also includes an injection disk (5) and a combustion chamber, wherein a plurality of baffle nozzles (4) pass through the injection disk (5) and are fixedly connected to the injection disk (5), the injection disk (5) is fixed in the combustion chamber, an axial end of the bushing body is bonded to the injection disk (5) by an adhesive, and a circumferential side wall of the bushing body is bonded to an inner wall of the combustion chamber by an adhesive.

10. A rocket engine according to claim 9, characterized in that: The adhesive is a methacrylate adhesive.

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