Noise reduction mechanism and aero-engine

Abstract

The invention provides a noise reduction mechanism and an aero-engine, the noise reduction mechanism comprises a mounting runner and a noise reduction liner, and the mounting runner is located on the inner wall of a cartridge receiver; the noise reduction lining is laid on the mounting flow channel, airflow passing through the noise reduction lining enters the fan, and the noise reduction lining comprises at least two noise reduction units; wherein each noise reduction unit at least comprises two sound absorption units, and the sound absorption frequencies of the two sound absorption units are different. According to the noise reduction mechanism, each noise reduction unit comprises at least two sound absorption units, so that the noise reduction mechanism can absorb noise of at least two different frequencies, the sound absorption frequency is widened, and multiple noise attenuation is achieved to the maximum extent.

Description

Technical Field

[0001] The present invention relates to the technical field of fan noise reduction, and in particular to a noise reduction mechanism and an aircraft engine. Background Art

[0002] Due to the growth of aircraft engine transport volume and load, aircraft noise has attracted increasing attention. At the same time, urban construction is expanding, and urban areas are getting closer and closer to airports, making aircraft noise pollution to the environment increasingly serious.

[0003] In engine noise control, acoustic lining is the most effective means of noise reduction. The typical and most commonly used single-layer acoustic lining is mainly composed of a panel, a honeycomb core and a rigid back panel. The panel often has a perforated plate, a wire mesh or a perforated sandwich plate. The honeycomb core is connected to the panel to form a core cavity. The rigid back panel connected to the honeycomb core makes the core cavity sealed and isolated from each other, thereby forming a single resonator.

[0004] However, the current sound lining has the problem of narrow sound absorption frequency band and single sound absorption measure. Based on this, the inventor of the present application proposes a noise reduction mechanism and an aircraft engine to solve the above technical problems. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the defects of the prior art that the sound absorbing band of the sound liner is narrow and the sound absorbing measures are single, and to provide a noise reduction mechanism and an aircraft engine.

[0006] The present invention solves the above technical problems through the following technical solutions:

[0007] The present invention provides a noise reduction mechanism, which is characterized by comprising:

[0008] The flow channel is installed on the inner wall of the casing;

[0009] A noise reduction liner is laid on the installation flow channel, and the airflow through the noise reduction liner enters the fan. The noise reduction liner includes at least two noise reduction units; wherein,

[0010] Each of the noise reduction units includes at least two sound absorbing units, and the sound absorbing frequencies of the two sound absorbing units are different.

[0011] According to an embodiment of the present invention, adjacent sound absorbing units are separated by a perforated partition plate.

[0012] According to one embodiment of the present invention, each of the sound absorbing units comprises a porous panel, at least one resonance cavity and a back plate, the porous panel is provided with sound absorbing holes connected to the resonance cavity, and the resonance cavity is located between the porous panel and the back plate.

[0013] According to an embodiment of the present invention, each of the sound absorbing units comprises at least two resonance cavities, and at least two of the resonance cavities have different lengths in the vertical direction between the porous panel and the back panel.

[0014] According to an embodiment of the present invention, each of the sound absorbing units comprises at least two resonance cavities, and at least two of the resonance cavities have different vertical angles with respect to the porous panel to the back plate.

[0015] According to an embodiment of the present invention, each of the sound absorbing units includes at least two resonance cavities, and radial dimensions of at least two of the resonance cavities are different.

[0016] According to one embodiment of the present invention, each of the sound absorbing units comprises at least two resonance cavities, and at least two of the resonance cavities have different vertical lengths, radial dimensions, and angles with the vertical direction along the vertical direction between the porous panel and the back panel.

[0017] According to one embodiment of the present invention, each of the sound absorbing units comprises at least two resonance cavities, and the cross-sectional dimensions of the resonance cavities increase gradually along the radial direction between the porous panel and the back plate.

[0018] According to an embodiment of the present invention, each of the sound absorbing units comprises at least two resonance cavities, wherein the resonance cavity comprises a first cavity and a second cavity along its axial direction, and the first cavity is arranged close to one side of the porous panel;

[0019] A cylindrical silencer in the first cavity and / or the second cavity.

[0020] According to one embodiment of the present invention, the axial direction of the cylindrical silencer is set at an angle with the axial direction of the first cavity and / or the second cavity;

[0021] The cross-sectional shape of the cylindrical silencer is different from the cross-sectional shapes of the first cavity and the second cavity.

[0022] The present invention also provides an aircraft engine, which is characterized in that the aircraft engine includes the noise reduction mechanism as described above.

[0023] The positive and progressive effects of the present invention are:

[0024] In the noise reduction mechanism of the present invention, each noise reduction unit includes at least two sound absorbing units, so that the noise reduction mechanism can absorb at least two noises of different frequencies, broaden the sound absorption frequency, and maximize the multiple attenuation of noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments, in which:

[0026] Figure 1 It is a partial structural schematic diagram of the aircraft engine of the present invention;

[0027] Figure 2 It is a structural schematic diagram of the noise reduction unit in the noise reduction mechanism of the present invention;

[0028] Figure 3 for Figure 2 A schematic cross-sectional view of a perforated baffle in a noise reduction unit shown;

[0029] Figure 4 A schematic diagram of an embodiment of a resonant cavity of the present invention;

[0030] Figure 5 is a schematic diagram of another embodiment of the resonant cavity of the present invention;

[0031] Figure 6 is a schematic diagram of another embodiment of the resonant cavity of the present invention;

[0032] Figure 7 It is a schematic diagram of another embodiment of the resonant cavity of the present invention.

[0033] 10. Install the flow channel;

[0034] 20. Receiver;

[0035] 30. Noise reduction lining; 310. Noise reduction unit; 320. Sound absorbing unit; 321. Perforated partition; 322. Porous panel; 3220. Sound absorbing hole; 323. Resonance cavity; 324. Back plate; 325. First cavity; 326. Second cavity; 327. Columnar silencer; 328. Porous metal mesh; 329. Porous medium plate. DETAILED DESCRIPTION

[0036] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0037] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Reference will now be made in detail to preferred embodiments of the present invention, examples of which are shown in the accompanying drawings. Wherever possible, the same reference numerals will be used in all drawings to represent the same or similar parts. In addition, although the terms used in the present invention are selected from well-known and commonly used terms, some of the terms mentioned in the specification of the present invention may be selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant parts of the description herein. In addition, it is required to understand the present invention not only by the actual terms used, but also by the meaning implied by each term.

[0038] Please refer to Figure 1The present invention provides an aircraft engine, including a casing 20, the casing 20 has a gas flow channel, and a mounting flow channel 10 is formed in front of a fan, and a noise reduction mechanism is provided on the mounting flow channel 10 for reducing fan noise.

[0039] Please refer to Figure 1 and Figure 2 In one embodiment, the noise reduction mechanism includes an installation flow channel 10 and a noise reduction liner 30. The installation flow channel 10 corresponds to the gas flow channel portion of the casing 20 located in front of the fan. The noise reduction liner 30 is laid on the installation flow channel 10. The airflow enters the fan through the noise reduction liner 30 to reduce the fan noise.

[0040] The noise reduction lining 30 includes at least two noise reduction units 310 . Each noise reduction unit 310 includes at least two sound absorbing units 320 . The sound absorbing frequencies of the two sound absorbing units 320 are different.

[0041] It can be seen that, unlike conventional single-function sound linings, the sound lining structure of the present invention can absorb noises of different frequencies, further broaden the sound absorption frequency band, and is more conducive to noise attenuation.

[0042] Please refer to Figure 2 and Figure 3 In one embodiment, adjacent sound absorbing units 320 are separated by a perforated partition 321 .

[0043] Because the sound absorbing units 320 are arranged at intervals and adjacent sound absorbing units 320 are separated by the perforated partitions 321 , a small amount of noise that is not dissipated between the sound absorbing units 320 can be further dissipated through the perforated partitions 321 .

[0044] Each sound absorbing unit 320 includes a porous panel 322, at least one resonance cavity 323 and a back plate 324. The porous panel 322 is provided with a sound absorbing hole 3220 connected to the resonance cavity 323. The resonance cavity 323 is located between the porous panel 322 and the back plate 324. The specific structure of the sound absorbing hole 3220 is composed of a plurality of small holes, which are evenly spaced and densely distributed in the area of ​​the sound absorbing hole 3220.

[0045] The porous panel 322 faces the installation flow channel 10, and the airflow enters the resonance cavity 323 through the porous panel 322, and then is silenced in the resonance cavity 323. The back plate 324 is connected to the casing 20 by bonding, welding, threaded detachable connection, etc., and the specific installation method is not limited here.

[0046] In one embodiment, each sound absorbing unit 320 includes at least two resonance cavities 323 , and the two resonance cavities 323 have different lengths in the vertical direction between the porous panel 322 and the back panel 324 .

[0047] The airflow enters the resonance cavity 323 through the sound absorbing holes 3220 . Since the resonance cavity 323 has different lengths in the vertical direction, the resonance cavities 323 of different lengths can absorb noises of different frequency bands.

[0048] In one embodiment, each sound absorbing unit 320 includes at least two resonance cavities 323 , and the at least two resonance cavities 323 have different vertical angles with respect to the porous panel 322 and the back panel 324 .

[0049] Between the porous panel 322 and the back panel 324, at the same height, the inclined resonance cavity 323 has a larger sound absorption length and a larger sound absorption volume than the vertical resonance cavity 323. The normal sound absorption length is beneficial for absorbing noise in the lower frequency band, while the larger sound absorption volume can improve the noise absorption effect.

[0050] In one embodiment, each sound absorbing unit 320 includes at least two resonance cavities 323 , and radial dimensions of the at least two resonance cavities 323 are different.

[0051] The resonance cavities 323 of different radial sizes have different sound absorption volumes corresponding to the same length, and different sound absorption volumes are conducive to absorbing noises of different frequency bands.

[0052] In one embodiment, each sound absorbing unit 320 includes at least two resonance cavities 323 , and the at least two resonance cavities 323 have different vertical lengths, radial dimensions, and vertical angles between the porous panel 322 and the back plate 324 .

[0053] When the length, radial dimension and included angle of the resonance cavity 323 are different, the sound absorbing band of the sound absorbing unit 320 will be wider, which is conducive to absorbing noise in a wider frequency band.

[0054] In one embodiment, each sound absorbing unit 320 includes at least two resonance cavities 323 , and the cross-sectional dimensions of the resonance cavities 323 increase gradually along the radial direction between the porous panel 322 and the back panel 324 .

[0055] That is, the resonance cavity 323 is in a truncated cone shape, which is beneficial to extend the length of the inner wall of the resonance cavity 323 and increase the volume of the resonance cavity 323, thereby improving the noise absorption effect.

[0056] In one embodiment, each sound absorbing unit 320 includes at least two resonance cavities 323, and the resonance cavity 323 includes a first cavity 325 and a second cavity 326 along its axial direction. The first cavity 325 is arranged close to one side of the porous panel 322; a cylindrical silencer 327 is provided in the first cavity 325 and / or the second cavity 326.

[0057] A cylindrical silencer 327 is assembled in the resonance cavity 323 to increase the length of the resonance cavity 323, which is beneficial for absorbing medium and low frequency noise.

[0058] Further, the axial direction of the cylindrical silencer 327 is set at an angle with the axial direction of the first cavity 325 and / or the second cavity 326. The cross-sectional shape of the cylindrical silencer 327 is different from the cross-sectional shape of the first cavity 325 and the second cavity 326.

[0059] That is, the resonance cavities 323 of different lengths can adapt to the absorption of noises in different frequency bands, and further on the basis of the cylindrical silencer 327, a certain vertical frequency band can be further added on the basis of the previous sound absorption band to achieve the absorption of noises in lower frequency bands, which is conducive to widening the sound absorption range.

[0060] In one embodiment, a layer of porous metal mesh 328 is laid in the resonance cavity 323 , and a porous medium plate 329 is provided on the side of the porous metal mesh 328 facing the back plate 324 .

[0061] A layer of metal mesh is designed on the inner wall of the resonance cavity 323 , and the noise reduction effect is better than the effect of only dissipating through the inner wall of the resonance cavity 323 itself.

[0062] Please refer to Figures 4 to 7 In one embodiment, each noise reduction unit 310 includes four sound absorbing units 320 , which are respectively a first sound absorbing unit 320 , a second sound absorbing unit 320 , a third sound absorbing unit 320 , and a fourth sound absorbing unit 320 .

[0063] Specifically, the apertures of the multiple small holes of the sound absorbing holes 3220 of the porous panel 322 of the first sound absorbing unit 320 range from 0.3 mm to 3.5 mm, and the resonance cavities 323 with different radial sizes correspond to the lower parts of the sound absorbing holes 3220 .

[0064] Some of the multiple resonance cavities 323 are vertically arranged and some are inclined, and the length between the resonance cavities 323 ranges from 2cm to 4cm. When sound waves enter the resonance cavity 323 through the sound-absorbing holes 3220, they are absorbed and dissipated by the porous metal mesh 328 on the inner wall of the resonance cavity 323, and the small amount of noise propagating to the bottom of the resonance cavity 323 is absorbed by the porous medium plate 329 at the bottom, which can be used to absorb noise in the medium and high frequency bands.

[0065] The apertures of the multiple small holes of the sound absorbing holes 3220 of the porous panel 322 of the second sound absorbing unit 320 are in the range of 0.5 mm to 3 mm, and a polygonal resonance cavity 323 is arranged below the sound absorbing holes 3220. The polygonal resonance cavity 323 is arranged vertically and has different lengths, and a porous metal wire mesh 328 is laid on the inner wall of the resonance cavity 323. Sound waves enter the polygonal resonance cavity 323 through the sound absorbing holes 3220 and are absorbed and dissipated by the porous metal wire mesh 328 in the polygonal resonance cavity 323.

[0066] Specifically, the length of the polygonal resonance cavity 323 ranges from 5 cm to 9 cm, thereby being used to absorb medium-frequency noise and low-frequency noise.

[0067] The apertures of the multiple small holes of the sound-absorbing holes 3220 of the porous panel 322 of the third sound-absorbing unit 320 are in the range of 1mm-5mm. A cylindrical resonance cavity 323 and a regular hexagonal resonance cavity 323 are arranged below the sound-absorbing holes 3220. The length of the resonance cavity 323 is 2cm-9cm. A cylindrical silencer 327 is additionally arranged in the regular hexagonal resonance cavity 323 to form a hybrid resonance cavity 323. The cylindrical silencer 327 can modulate the incoming sound waves and increase the length of the resonance cavity 323, which can be used to eliminate high, medium and low frequency noise. Similarly, a porous medium plate 329 is laid at the bottom of the resonance cavity 323 to absorb excess noise.

[0068] The apertures of the multiple small holes of the sound absorbing holes 3220 of the porous panel 322 of the fourth sound absorbing unit 320 are in the range of 1 mm to 10 mm, the resonance cavity 323 below the sound absorbing holes 3220 is in the shape of a truncated cone, the length of the resonance cavity 323 is 3 cm to 6 cm, the inner wall of the resonance cavity 323 is provided with a porous metal wire mesh 328, and the bottom of the resonance cavity 323 is provided with a porous medium plate 329. The truncated cone-shaped resonance cavity 323 helps to extend the length of the inner wall of the resonance cavity 323 and increase the volume of the resonance cavity 323, thereby improving the absorption effect of medium-frequency and low-frequency noise, and the porous medium plate 329 is used to absorb excess noise.

[0069] The resonance cavity 323 in the above four types of sound absorbing units 320 is selected from Figures 4 to 7 The combination of at least two of the resonant cavity 323 is not unique, and the above examples are only some of the combinations. For the absorption of noise in different frequency bands, different combinations can be selected for coordination, and the combination is not limited here.

[0070] Regarding the structure of the resonance cavity 323, the four sound absorbing units 320 cover the frequency bands of high frequency, medium frequency and low frequency, thereby satisfying the absorption of noise in a wider frequency band.

[0071] That is, by setting the resonance cavity 323 to a combination structure of different heights, different inclinations, different apertures and different shapes, noise of different frequency bands can be absorbed, thereby satisfying the absorption of noise of a wider frequency band. At the same time, adjusting the internal volume of the resonance cavity 323 can improve its sound absorption effect.

[0072] The noise reduction unit 310 is further divided to form a plurality of sound absorbing units 320 . Each sound absorbing unit 320 has a different design for the resonance cavity 323 , thereby having sound absorbing effects in different frequency bands, satisfying the absorption of noise from low frequency bands to high frequency bands, and having a wide-band sound absorbing effect.

[0073] In summary, in view of the problem that the existing sound lining has a narrow sound absorption frequency band, the present invention sets a plurality of independent sound absorbing units 320, designs vertical and inclined short cylindrical resonance cavities 323, mixed resonance cavities 323, regular hexagonal resonance cavities 323 and truncated cone resonance cavities 323 of different heights, and meets the requirements of absorbing low-frequency to high-frequency band noise.

[0074] The existing sound lining has a single sound absorption measure. The present invention uses resonance cavities 323 at different angles to attenuate part of the noise, and uses a porous metal mesh 328 on the inner wall of the resonance cavity 323 to enhance the sound absorption effect. It also involves a mixed resonance cavity 323, modulating the incoming sound waves, and setting a perforated partition 321 between adjacent sound absorbing units 320, and a porous medium plate 329 at the bottom of the resonance cavity 323, absorbing the dissipated noise in multiple dimensions, and maximizing the purpose of multiple noise attenuation.

[0075] The existing sound liner has poor sound absorption effect. In this regard, the conventional sound liner relies on the resonance cavity 323 to vertically avoid friction to dissipate sound waves, and the sound absorption effect is limited.

[0076] The present invention designs oblique resonance cavities 323 of different angles and resonance cavities 323 of different sizes and shapes, and simultaneously sets a porous metal wire mesh 328 on the inner wall of the resonance cavity 323 to dissipate noise, and the noise reduction effect is better than the effect of only dissipating through the inner wall of the resonance cavity 323 itself.

[0077] The present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or multiple times in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0078] Although the present invention is disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope defined by the claims of the present invention.

Claims

1. A noise reduction mechanism, arranged in a casing, characterized in that: include: The flow channel is installed on the inner wall of the casing; A noise reduction liner is laid on the installation flow channel, and the airflow through the noise reduction liner enters the fan. The noise reduction liner includes at least two noise reduction units; wherein, Each of the noise reduction units includes at least two sound absorbing units, and the sound absorbing frequencies of the two sound absorbing units are different.

2. The noise reduction mechanism according to claim 1, characterized in that: Adjacent sound absorbing units are separated by perforated partitions.

3. The noise reduction mechanism according to claim 1, characterized in that: Each of the sound absorbing units comprises a porous panel, at least one resonance cavity and a back plate. The porous panel is provided with sound absorbing holes connected to the resonance cavity. The resonance cavity is located between the porous panel and the back plate.

4. The noise reduction mechanism according to claim 3, characterized in that: Each of the sound absorbing units includes at least two resonance cavities, and at least two of the resonance cavities have different lengths in the vertical direction between the porous panel and the back plate.

5. The noise reduction mechanism according to claim 3, characterized in that: Each of the sound absorbing units includes at least two resonance cavities, and at least two of the resonance cavities have different vertical angles from the porous panel to the back plate.

6. The noise reduction mechanism according to claim 3, characterized in that: Each of the sound absorbing units includes at least two resonance cavities, and radial dimensions of at least two of the resonance cavities are different.

7. The noise reduction mechanism according to claim 3, characterized in that: Each of the sound absorbing units comprises at least two resonance cavities, and at least two of the resonance cavities have different lengths in the vertical direction between the porous panel and the back plate, different radial dimensions, and different angles with the vertical direction.

8. The noise reduction mechanism according to claim 3, characterized in that: Each of the sound absorbing units comprises at least two resonance cavities, and the cross-sectional dimensions of the resonance cavities increase gradually along the radial direction between the porous panel and the back plate.

9. The noise reduction mechanism according to claim 3, characterized in that: Each of the sound absorbing units comprises at least two resonance cavities, wherein the resonance cavity comprises a first cavity and a second cavity along its axial direction, and the first cavity is arranged close to one side of the porous panel; A cylindrical silencer in the first cavity and / or the second cavity.

10. The noise reduction mechanism according to claim 9, characterized in that: The axial direction of the cylindrical silencer is set at an angle with the axial direction of the first cavity and / or the second cavity; The cross-sectional shape of the cylindrical silencer is different from the cross-sectional shapes of the first cavity and the second cavity.

11. The noise reduction mechanism according to claim 3, characterized in that: A layer of porous metal wire mesh is laid in the resonance cavity, and a porous medium plate is provided on the side of the porous metal wire mesh facing the back plate.

12. An aircraft engine, characterized in that: The aircraft engine comprises the noise reduction mechanism according to any one of claims 1-11.

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