CN219691642U

CN219691642U - Aeroengine exhaust muffler

Info

Publication number: CN219691642U
Application number: CN202321395620.0U
Authority: CN
Inventors: 汪安全; 刘海艳; 汪安平
Original assignee: Individual
Current assignee: Individual
Priority date: 2023-06-02
Filing date: 2023-06-02
Publication date: 2023-09-15
Anticipated expiration: 2033-06-02

Abstract

The utility model provides an aeroengine exhaust muffler, which comprises an outer shell, an air inlet flange, an air outlet flange, a primary muffler plate, a secondary muffler plate, a tertiary muffler plate, a low-frequency resonance cavity and a middle-high frequency muffler cavity, wherein the air inlet flange and the air outlet flange are respectively arranged at two ends of the outer shell, the primary muffler plate, the secondary muffler plate and the tertiary muffler plate are sequentially arranged in the outer shell along the direction from the air inlet flange to the air outlet flange, the low-frequency resonance cavity is arranged between the air inlet flange and the secondary muffler plate in the outer shell, the middle-high frequency muffler cavity is arranged between the secondary muffler plate and the air outlet flange in the outer shell, two layers of metal thin-wall plates are arranged in the low-frequency resonance cavity, two layers of metal perforated sound absorbing plates are arranged in the middle-high frequency muffler cavity, and high-temperature resistant sound absorbing cotton is arranged between the two layers of metal perforated sound absorbing plates. The utility model improves the treatment of medium-high frequency jet flow noise, thereby improving the noise reduction effect of the engine test bed.

Description

Aeroengine exhaust muffler

Technical Field

The utility model relates to the technical field of mufflers, in particular to an aeroengine exhaust muffler.

Background

With the rapid development of national economy, aviation science research is also expanding in a large area, and engines are the heart of aircraft, so that the research of the engines is of great importance, and various performance tests of the engines are generally required in a laboratory, and the engines are improved and debugged through test data. The engine has the common property no matter what type of engine is adopted, namely the strong noise generated by work, through the noise detection of different types of engines, the exhaust noise reaches more than 100dB, and an engine laboratory is generally built in an office area, a school and an industrial park and faces the national noise control standard, so that a strong contradiction is formed, and the noise generated by an engine test bed seriously affects the surrounding environment and the physical and psychological health of scientific researchers.

At present, noise reduction of an engine test bed is quite large, but the noise reduction is not quite ideal, the input cost is quite high, and at present, a huge noise elimination tower is built outside an exhaust port to solve exhaust noise, so that the effect is not ideal.

Disclosure of Invention

In order to solve the problems, the utility model provides an aeroengine exhaust muffler to more exactly solve the problem that the noise reduction effect of the engine test bed is not ideal.

The utility model is realized by the following technical scheme: the utility model provides an aeroengine exhaust silencer, includes shell body, air inlet flange, gas vent flange, one-level noise elimination board, second grade noise elimination board, tertiary noise elimination board, low frequency resonant cavity and well high frequency noise elimination chamber, the both ends of shell body are equipped with air inlet flange and gas vent flange respectively, the inside one-level noise elimination board, second grade noise elimination board and the tertiary noise elimination board of being equipped with in proper order of shell body along the direction of air inlet flange to gas vent flange, it is established to low frequency resonant cavity to lie in between air inlet flange to the second grade noise elimination board in the shell body, it is established to be established to the medium-high frequency noise elimination chamber to lie in between second grade noise elimination board to the gas vent flange in the shell body, be equipped with two-layer metal thin wall board in the low frequency resonant cavity, well high frequency noise elimination intracavity is equipped with two-layer metal perforation abatvoix, two-layer be equipped with high temperature resistant sound cotton between the metal perforation abatvoix.

Further, the low-frequency resonant cavity is divided into a first silencing cavity and a second silencing cavity by the first-stage silencing plate, and the middle-high-frequency silencing cavity is divided into a third silencing cavity and a fourth silencing cavity by the third-stage silencing plate.

Further, the peripheral wall of the air inlet flange is provided with an air inlet array round hole.

Further, a first array of round holes is formed in the first-stage silencing plate.

Further, a second array round hole is formed in the second-stage silencing plate, and a cylinder sleeve is fixedly connected in the second array round hole.

Further, a third array of round holes are formed in the three-stage muffler plate.

Further, the peripheral wall of the exhaust port flange is provided with an exhaust array round hole.

Further, a plurality of metal supporting blocks are fixedly connected between the metal thin wall plate, the metal perforated sound absorbing plate and the inner wall of the outer shell.

Further, the high-temperature-resistant sound-absorbing cotton comprises a full-frequency sound-absorbing cotton layer and high-silica sound-absorbing cotton layers fixedly connected to two sides of the full-frequency sound-absorbing cotton layer.

Further, the penetration rate of the metal perforated sound-absorbing plate of the outer layer is 35%, the penetration rate of the metal perforated sound-absorbing plate of the inner layer is 30%, the full-frequency sound-absorbing cotton layer is 40mm thick, and the high-silica sound-absorbing cotton layer is 5mm thick.

The utility model has the beneficial effects that:

1. the sound insulation is high, and the treatment of the jet noise with medium and high frequency is improved;

2. the product is produced and can be recycled;

3. the sound insulation performance is improved, and the high temperature resistance meets 800 ℃;

4. the pressure loss is less;

5. the installation is simple, and simultaneously the maintenance cost is reduced.

Drawings

FIG. 1 is a schematic view of the overall structure of an aircraft engine exhaust muffler according to the present utility model;

fig. 2 is a schematic diagram of an air inlet flange structure of an air engine exhaust muffler according to the present utility model;

FIG. 3 is a schematic view of a two-stage muffler plate structure of an aircraft engine exhaust muffler according to the present utility model;

fig. 4 is a schematic view of a high-temperature-resistant sound-absorbing cotton structure of an aeroengine exhaust muffler provided by the utility model.

The reference numerals are as follows:

1. an outer housing; 2. an air inlet flange; 21. an air inlet array round hole; 3. an exhaust port flange; 31. an exhaust array circular hole; 4. a first-stage muffler plate; 41. a first array of circular holes; 5. a second-stage muffler plate; 51. a second array of circular holes; 52. a cylindrical sleeve; 6. three-stage muffler plates; 61. a third array of circular holes; 7. a low frequency resonant cavity; 71. a first sound-damping chamber; 72. a second sound-damping chamber; 8. a medium-high frequency sound-damping cavity; 81. a third sound-damping chamber; 82. a fourth sound-damping chamber; 9. a metal Bao Biban; 10. a metal perforated sound absorbing panel; 11. high-temperature-resistant sound-absorbing cotton; 111. a full-frequency sound-absorbing cotton layer; 112. a high silica sound absorbing cotton layer; 12. and a metal supporting block.

Detailed Description

In order to more clearly and completely describe the technical scheme of the utility model, the utility model is further described below with reference to the accompanying drawings.

Referring to fig. 1-4, the utility model provides an aeroengine exhaust muffler, which comprises an outer shell 1, an air inlet flange 2, an air outlet flange 3, a primary muffler plate 4, a secondary muffler plate 5, a tertiary muffler plate 6, a low-frequency resonant cavity 7 and a medium-high frequency muffler cavity 8, wherein the two ends of the outer shell 1 are respectively provided with the air inlet flange 2 and the air outlet flange 3, the peripheral wall of the air inlet flange 2 is provided with an air inlet array round hole 21, the peripheral wall of the air outlet flange 3 is provided with an exhaust array round hole 31, the diameter of the exhaust array round hole 31 is 35mm, the inner part of the outer shell 1 is sequentially provided with a primary muffler plate 4, a secondary muffler plate 5 and a tertiary muffler plate 6 along the direction from the air inlet flange 2 to the air outlet flange 3, the primary muffler plate 4 is provided with a first array round hole 41, the secondary muffler plate 5 is provided with a second array round hole 51, the interior of the second array round hole 51 is fixedly connected with a cylinder sleeve 52, the tertiary muffler plate 6 is provided with a third array round hole 61, the inner part of the outer shell 1 is provided with a low-frequency cavity 7 between the air inlet flange 2 and the secondary muffler plate 5, the low-frequency cavity 7 is provided with a thin-wall plate 12, the low-frequency cavity 7 is provided with a thin-layer 12, and the thin-layer is provided with a thin-layer 12 and a thin-layer 9 is formed by the thin-layer of a thin-layer metal thin-wall plate, and the thin-wall panel is formed by the thin-layer metal resonator.

The low-frequency resonant cavity 7 mainly utilizes the characteristics of materials and sound waves, utilizes the low-frequency resonant effect and the middle-high frequency anastomosis effect to realize the purpose of noise reduction, mainly adopts a double-layer metal thin-wall plate 9 with the same thickness to form two hollow cavities with the outer shell 1 through a middle metal supporting block 12, and after the sound waves are radiated to the two layers of metal thin-wall plates 9 with the same thickness, the metal thin-wall plate 9 can vibrate by the low frequency 125-500HZ and the middle-high frequency 2000-4000HZ, so that low-frequency energy is consumed, iron plates are used in the cavities, the problem of high temperature is solved, and after low-frequency noise is effectively controlled, the noise control of the middle-high frequency band is correspondingly weakened.

The middle-high frequency sound-absorbing cavity 8 is arranged between the second-level sound-absorbing plate 5 and the air outlet flange 3 in the outer shell body 1, the middle-high frequency sound-absorbing cavity 8 is divided into a third sound-absorbing cavity 81 and a fourth sound-absorbing cavity 82 by the third-level sound-absorbing plate 6, the air outlet flange 3 extends into the fourth sound-absorbing cavity 82 by adopting an inner sleeve type, two layers of metal perforation sound-absorbing plates 10 are arranged in the middle-high frequency sound-absorbing cavity 8, the penetration rate of the outer layer metal perforation sound-absorbing plates 10 is 35%, the penetration rate of the inner layer metal perforation sound-absorbing plates 10 is 30%, metal supporting blocks 12 are used for supporting and fixing the two layers of plates to form a 50mm hollow layer, the metal supporting blocks 12 are used for supporting and forming a 30mm thick hollow layer between the outer layer metal perforation sound-absorbing plates 10 and the outer shell body 1, high-temperature resistant sound-absorbing cotton 11 is arranged between the two layers of metal perforation sound-absorbing plates 10, the high-temperature resistant sound-absorbing cotton 11 comprises a full-frequency sound-absorbing cotton layer 111 and high-absorbing cotton layers 112 fixedly connected to two sides of the full-frequency cotton layer 111, the full-frequency sound-absorbing cotton layer 111 is 40mm sound-absorbing cotton layer 48K, and the high sound-absorbing cotton layer 112 is 5mm thick.

The middle-high frequency sound-absorbing cavity 8 is mainly used for treating middle-high frequency noise, the noise of an aeroengine is mainly in the middle-high frequency, the most effective treatment mode of the hollow frequency is resistive sound absorption, sound absorption structures are mainly adopted for reducing noise, a cavity structure is mainly formed by a metal perforated sound-absorbing plate 10 and an outer shell 1 through a metal supporting block 12, a 50mm thick sound-absorbing structure is arranged in the two layers of the metal perforated sound-absorbing plate 10, the sound-absorbing structure is formed by extruding 40mm superfine glass wool which is wrapped by 5mm high silica sound-absorbing cotton, the superfine glass wool is formed by chaotic weaving of fine glass, the inside of the superfine glass wool is transparent complex pores, the sound-absorbing performance of the middle-high frequency is very good, the outside of the superfine glass wool is wrapped by the high silica sound-absorbing cotton, the high temperature resistant sound-absorbing structure can resist 800 ℃, the combination of two sound-absorbing materials can cope with the severe environment of exhaust of all engines, the thickness, the aperture and the perforation rate of the two layers of the metal perforated sound-absorbing plate 10 are different, the sound-absorbing structure is complex and beneficial to noise elimination, and the hollow back cavity of 30-50mm is arranged between the outer layer of the metal perforated sound-absorbing plate 10 and the outer shell 1.

In summary, the air inlet flange 2 is connected with the exhaust port of the engine, the high-speed air flow enters the first silencing cavity 71 through the air inlet flange 2, a larger compression process is formed when the air flow passes through the air inlet array round holes 21 on the air inlet flange 2, the air flow is forced to reduce the speed, meanwhile, the air flow enters the first silencing cavity 71 after being compressed once, a multi-layer hollow structure is formed between the metal thin wall plate 9 with a very thin wall thickness and the outer shell 1 through the metal supporting blocks 12, after the sound wave irradiates to the surface of the metal thin wall plate 9, the vibration of the plate is caused, the other part of sound wave penetrates through the inner layer metal thin wall plate 9 directly and then is reflected to the outer layer metal thin wall plate 9, a hollow layer is arranged between the outer layer metal thin wall plate 9 and the outer shell 1, the sound wave can reflect the metal thin wall plate 9 to generate vibration, meanwhile, the noise energy is greatly reduced, and the metal thin wall plate 9 is made of a high-temperature resistant material compared with the traditional cavity added sound absorbing material;

after passing through the first silencing cavity 71, the air flow enters into the second silencing cavity 72 through the first array of round holes 41 on the first-stage silencing plate 4, the inner structure of the cavity is consistent with that of the first silencing cavity 71, the two cavities adopt the means that the metal thin-wall plate 9 resonates to reduce low-frequency noise, after the low-frequency noise is reduced, the penetrating capacity of the noise in the middle-high frequency band is relatively lower, the propagation distance is closer, and further noise control is facilitated.

Through experimental study, when the air flow passes through the long and narrow cylinder sleeve 52, the noise reduction effect is better than that of a round hole, and is improved by at least 3 decibels, and the second effect of the designed cylinder structure is that the air flow passing through the cylinder sleeve 52 can accelerate to pass through, so that a negative pressure effect is formed in the cavity, the exhaust effect is improved, and the pressure loss is reduced.

After the air flow passes through the cylindrical sleeve 52 on the secondary sound attenuation plate 5, the air flow enters the third sound attenuation cavity 81, two layers of metal perforation sound absorption plates 10 are arranged on the peripheral outer walls, the perforation rate of the outer layer of the metal perforation sound absorption plates 10 is 35%, the perforation rate of the inner layer of the metal perforation sound absorption plates 10 is 30%, the two layers of plates are supported and fixed by adopting metal supporting blocks 12 to form a 50mm hollow layer, a 30mm thick hollow layer is formed between the outer layer of the metal perforation sound absorption plates 10 and the outer shell 1 by supporting the metal supporting blocks 12, sound absorption cotton is filled in the middle of the two layers of the metal perforation sound absorption plates 10, the sound absorption cotton is 48K sound absorption cotton with the thickness of 40mm, the 5mm thick high silica sound absorption cotton is wrapped outside, the sound absorption is realized, the sound absorption can simultaneously resist high temperature of more than 800 ℃, the sound wave is expanded and reflected in the cavity, the sound absorption coefficient of the material reaches more than 0.9 by matching with the back cavity between the outer shell 1, and the sound absorption effect of the metal perforation sound absorption plates 10 with different perforation rates can avoid the anastomosis effect.

After the primary noise reduction of the middle and high frequency, sound waves enter the fourth noise reduction cavity 82 along with the airflow through the three-stage noise reduction plate 6, and the surrounding structure is consistent with the third noise reduction cavity 81, so that the middle and high frequency band is weakened again.

According to the practical application, the sound insulation performance of the structure reaches more than 40dB, after the two ends of the structure are connected with the exhaust silencing pipelines with the total length of 4 meters, the overall noise reduction effect reaches more than 50dB, the noise value generated during the turbojet engine test is 132dB, the noise value is detected by the factory boundary with the distance of 30 meters, the noise value reaches less than 44dB, the emission limit standard of the highest standard type region of the national standard is realized, and the technology is greatly broken through the data, so that the site selection problem of the test stand is also solved.

Of course, the present utility model can be implemented in various other embodiments, and based on this embodiment, those skilled in the art can obtain other embodiments without any inventive effort, which fall within the scope of the present utility model.

Claims

1. The utility model provides an aeroengine exhaust silencer, includes shell body (1), air inlet flange (2), gas vent flange (3), one-level noise elimination board (4), second grade noise elimination board (5), tertiary noise elimination board (6), low frequency resonant cavity (7) and well high frequency noise elimination chamber (8), a serial communication port, the both ends of shell body (1) are equipped with air inlet flange (2) and gas vent flange (3) respectively, the inside one-level noise elimination board (4), second grade noise elimination board (5) and tertiary noise elimination board (6) that are equipped with in proper order along the direction of air inlet flange (2) to gas vent flange (3) of shell body (1), be located in shell body (1) and establish to low frequency resonant cavity (7) between air inlet flange (5) to gas vent flange (3), be equipped with two-layer metal thin-wall board (9) in low frequency resonant cavity (7), be equipped with two-layer metal perforation sound absorbing board (10) in well high frequency noise elimination chamber (8), be equipped with between two-layer metal sound absorbing board (10) high temperature resistant sound absorbing board (11).

2. The aircraft engine exhaust muffler according to claim 1, characterized in that the low-frequency resonant cavity (7) is divided by a primary muffler plate (4) into a first muffler cavity (71) and a second muffler cavity (72), and the medium-high-frequency muffler cavity (8) is divided by a tertiary muffler plate (6) into a third muffler cavity (81) and a fourth muffler cavity (82).

3. The aircraft engine exhaust muffler according to claim 1, characterized in that the circumferential wall of the inlet flange (2) is provided with inlet array circular holes (21).

4. The aircraft engine exhaust muffler according to claim 1, characterized in that the primary muffler plate (4) is provided with a first array of circular holes (41).

5. The aeroengine exhaust muffler according to claim 1, wherein the secondary muffler plate (5) is provided with a second array of round holes (51), and a cylindrical sleeve (52) is fixedly connected in the second array of round holes (51).

6. The aircraft engine exhaust muffler according to claim 1, characterized in that the third-stage muffler plate (6) is provided with a third array of circular holes (61).

7. The aircraft engine exhaust muffler according to claim 1, characterized in that the peripheral wall of the exhaust port flange (3) is provided with exhaust array circular holes (31).

8. The aeroengine exhaust muffler according to claim 1, wherein a plurality of metal support blocks (12) are fixedly connected between the metal Bao Biban (9) and the metal perforated acoustic panel (10) and the inner wall of the outer casing (1).

9. The aeroengine exhaust muffler according to claim 1, wherein the high temperature resistant sound absorbing cotton (11) comprises a full frequency sound absorbing cotton layer (111) and high silica sound absorbing cotton layers (112) fixedly connected to both sides of the full frequency sound absorbing cotton layer (111).

10. The aircraft engine exhaust muffler according to claim 9, characterized in that the metal perforated acoustic panel (10) of the outer layer has a perforation ratio of 35%, the metal perforated acoustic panel (10) of the inner layer has a perforation ratio of 30%, the full-frequency acoustic cotton layer (111) is 40mm thick, and the high silica acoustic cotton layer (112) is 5mm thick.