Metamaterial silencer

Abstract

The invention provides a metamaterial silencer which comprises a main body section, the main body section comprises a low-frequency silencing module and an intermediate-frequency silencing module which are connected, and a plurality of low-frequency silencing channels arranged on the low-frequency silencing module are communicated with a plurality of intermediate-frequency silencing channels arranged on the intermediate-frequency silencing module in a one-to-one correspondence mode; at least one end of the main body section is connected with the transition section, the transition section comprises a plurality of air guide modules, and the multiple air guide modules are spliced with one another and are arranged in one-to-one correspondence with the multiple low-frequency noise elimination channels; each air guiding module comprises an outer frame, a plurality of air guiding modules and a plurality of air guiding modules, the inner frame is arranged in the outer frame and is hollow to form an air guide channel, the first end of the inner frame is fixedly connected with the first end of the outer frame in the circumferential direction, the second end of the inner frame is flush with the second end of the outer frame, the inner diameter of the inner frame is gradually reduced in the direction towards the second end of the inner frame, an elastic film is fixed to the inner wall of the inner frame, and the second end of the inner frame is arranged towards the main body section; the space between the inner frame and the outer frame is blocked by the second end of the inner frame, and a cavity is defined by the inner frame, the outer frame and the shielding plate.

Description

Technical Field

[0001] The present invention relates to the technical field of mufflers, and in particular to a metamaterial muffler. Background Art

[0002] Mufflers are widely used in ventilation ducts. Traditional mufflers use porous sound-absorbing materials or perforated plates installed on the side walls of the mufflers to achieve the effect of attenuating noise in the channel, but they cannot effectively attenuate low-frequency sound waves, resulting in the effect of traditional mufflers being good at medium and high frequency sound insulation and poor at low frequency sound insulation. In order to overcome this defect, relevant personnel have developed an acoustic metamaterial broadband sound isolator based on a thin film resonator. Its frequency range and sound insulation volume can be adjusted by adjusting the design of the thin film resonator and the volume of the sealed cavity to obtain low-frequency, medium-frequency or high-frequency sound insulation effects separately. Usually, when broadband noise needs to be reduced, the metamaterial muffler is composed of a multi-layer combination, and different layers are composed of low-frequency modules, medium-frequency modules and high-frequency modules to handle low-frequency, medium-frequency and high-frequency noise. At the same time, a transition section for introducing airflow is connected on the air inlet side. In actual scenarios, the channel of the traditional muffler needs to be made longer, while the channel length of the metamaterial muffler can be reduced to 1 / 4-1 / 5 to achieve the same sound insulation effect, giving full play to the advantage of small size. However, in some special scenarios where the installation space is severely limited, the size of the metamaterial silencer that integrates low-frequency, medium-frequency and high-frequency modules cannot meet the installation requirements under the premise of silencer noise in a wide frequency range, and still needs to be further reduced in size. Summary of the invention

[0003] In view of this, the present invention provides a metamaterial muffler to solve the above technical problems.

[0004] The metamaterial muffler provided by the present invention comprises:

[0005] A main body section, the main body section includes a low-frequency muffler module and a medium-frequency muffler module connected, the low-frequency muffler module is provided with a plurality of low-frequency muffler channels, the medium-frequency muffler module is provided with a plurality of medium-frequency muffler channels, and the plurality of low-frequency muffler channels and the plurality of medium-frequency muffler channels are connected one by one;

[0006] A transition section, at least one end of the main section is connected to the transition section, the transition section comprises a plurality of wind guide modules, the plurality of wind guide modules are spliced ​​with each other and are arranged one by one corresponding to the plurality of low-frequency silencer channels;

[0007] Each of the air guide modules comprises:

[0008] An outer frame, wherein the outer frame is hollow;

[0009] An inner frame, the inner frame is arranged in the outer frame, the inner frame is hollow to form an air guide channel, a first end of the inner frame is circumferentially fixedly connected to a first end of the outer frame, a second end of the inner frame is flush with a second end of the outer frame, and an inner diameter of the inner frame gradually decreases in a direction toward the second end thereof, an elastic film is fixed on an inner wall of the inner frame, and the second end of the inner frame is arranged toward the main body segment;

[0010] A shielding plate is provided at the second end of the inner frame to block the space between the inner frame and the outer frame, so that the inner frame, the outer frame and the shielding plate enclose a cavity.

[0011] Optionally, the inner frame is formed by connecting a plurality of side panels end to end in sequence, the first end of each side panel is connected to the first end of the outer frame, the second end of each side panel is connected to the shielding plate, and the elastic membrane is fixed to each side panel.

[0012] Optionally, each of the side panels is configured as an isosceles trapezoid, the upper base of each of the side panels is connected to the shielding plate, the lower base of each of the side panels is connected to the first end of the outer frame, and the waists of adjacent side panels are connected.

[0013] Optionally, the angle between the side panel and the outer frame ranges from 10° to 25°.

[0014] Optionally, the width of the elastic membrane accounts for 15%-30% of the width of the lower bottom of the side panel.

[0015] Optionally, the air guide module further includes: a partition plate, which is disposed in the cavity, connecting the inner frame and the outer frame, and partitioning the cavity into a plurality of independent chambers.

[0016] Optionally, the outer frame is formed by connecting a plurality of frame plates end to end in sequence.

[0017] Optionally, the metamaterial muffler further comprises: a reinforcement plate, wherein the reinforcement plate is fixedly connected to the circumference of the transition section.

[0018] Optionally, a mounting flange is fixed to one end of the transition section away from the main body section.

[0019] Optionally, a connecting flange is fixed to at least one end of the main body section, and the transition section is connected to the main body section via the connecting flange.

[0020] Compared with the prior art, the above technical solution provided by the present invention has at least the following beneficial effects:

[0021] By adopting the metamaterial silencer of the present invention, the low-frequency silencer module in the main section eliminates low-frequency noise, the medium-frequency silencer module eliminates medium-frequency noise, and each wind guide module in the transition section eliminates high-frequency noise by using a thin film resonator composed of a thin film and a cavity. Therefore, there is no need to set a high-frequency silencer module in the main section. With the cooperation of the low-frequency silencer module, the medium-frequency silencer module and the transition section, the silencer effect in a wide frequency range can be achieved, the overall length and volume of the silencer are reduced, and the advantages of the short channel and small volume of the metamaterial silencer are ensured, so that it can be widely used when space is limited. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A three-dimensional structural diagram of a metamaterial muffler according to an embodiment of the present invention;

[0023] Figure 2 for Figure 1 A three-dimensional structural diagram of the transition section of the metamaterial muffler shown;

[0024] Figure 3 for Figure 2 a side view of the transition section shown;

[0025] Figure 4 for Figure 2 A three-dimensional structural diagram of the air guide module of the transition section shown;

[0026] Figure 5 for Figure 4 A side view of the air guide module is shown.

[0027] Reference numerals:

[0028] 100: main section; 200: transition section; 1: air guide module; 11: outer frame; 111: frame plate; 12: inner frame; 121: side plate; 13: elastic membrane; 2: reinforcement plate; 3: mounting flange; 4: connecting flange. DETAILED DESCRIPTION

[0029] The embodiments of the present invention will be further described below in conjunction with the accompanying drawings. In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only simplified descriptions for the convenience of describing the present invention, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions.

[0030] Figure 1A three-dimensional structural diagram of a metamaterial muffler according to an embodiment of the present invention; Figure 2 for Figure 1 A three-dimensional structural diagram of the transition section of the metamaterial muffler shown; Figure 3 for Figure 2 a side view of the transition section shown; Figure 4 for Figure 2 A three-dimensional structural diagram of the air guide module of the transition section shown; Figure 5 for Figure 4 A side view of the air guide module is shown.

[0031] like Figure 1-Figure 5 As shown, the metamaterial silencer includes a main section 100 and a transition section 200. The main section 100 includes a low-frequency silencer module and a medium-frequency silencer module connected to each other. The low-frequency silencer module is provided with a plurality of low-frequency silencer channels, and the medium-frequency silencer module is provided with a plurality of medium-frequency silencer channels. The plurality of low-frequency silencer channels and the plurality of medium-frequency silencer channels are connected one by one. At least one end of the main section 100 is connected to the transition section 200. The transition section 200 includes a plurality of wind guide modules 1. The plurality of wind guide modules 1 are spliced ​​with each other and are arranged one by one with the plurality of low-frequency silencer channels. Each wind guide module 1 includes an outer frame 11, an inner frame 12 and a shielding plate. The outer frame 11 is hollow. The inner frame 12 is arranged in the outer frame 11, and the inner frame 12 is hollow to form an air guide channel. The first end of the inner frame 12 is circumferentially fixedly connected to the first end of the outer frame 11, and the second end of the inner frame 12 is flush with the second end of the outer frame 11, and the inner diameter of the inner frame 12 gradually decreases in the direction toward its second end. An elastic membrane 13 is fixed on the inner wall of the inner frame 12, and the second end of the inner frame 12 is arranged toward the main section 100; the baffle plate blocks the space between the inner frame 12 and the outer frame 11 at the second end of the inner frame 12, so that the inner frame 12, the outer frame 11 and the baffle plate enclose a cavity.

[0032] When the elastic membrane 13 is fixed to the inner wall of the inner frame 12, a certain pulling force is applied to the elastic membrane 13 so that it is in a certain degree of tension state, then a thin film resonator composed of a membrane and an air layer is formed between the elastic membrane 13 and the cavity, which has a greater sound absorption effect near the resonance frequency of the thin film resonator. When the noise passes through the air guide channel, the resonance state generated by the coupling between the cavity and the elastic membrane 13 interacts with the noise, which can effectively reduce the noise. The frequency of the resonance state is closely related to the volume of the cavity. The larger the volume of the cavity, the lower the resonance state frequency, and the lower the noise frequency band to which the wind guide module 1 responds; the smaller the volume of the cavity, the higher the resonance state frequency, and the higher the noise frequency band to which the wind guide module 1 responds. The volume of the cavity of each wind guide module 1 in the transition section 200 is smaller than the volume of the corresponding cavity in the intermediate frequency silencer module. Therefore, each wind guide module 1 in the transition section 200 can effectively silence the high-frequency noise in the noise. Thus, the low-frequency silencer module eliminates low-frequency noise, the medium-frequency silencer module eliminates medium-frequency noise, and the wind guide module 1 in the transition section 200 eliminates high-frequency noise. The combination of the three achieves the silencer effect of the metamaterial silencer on noise within a wide frequency range of low, medium and high frequencies.

[0033] By using the metamaterial silencer of the present invention, the low-frequency silencer module in the main section 100 eliminates low-frequency noise, the medium-frequency silencer module eliminates medium-frequency noise, and each wind guide module 1 in the transition section 200 eliminates high-frequency noise by using a thin film resonator composed of a thin film and a cavity. Therefore, there is no need to set a high-frequency silencer module in the main section 100. With the cooperation of the low-frequency silencer module, the medium-frequency silencer module and the transition section 200, the noise silencing effect in a wide frequency range can be achieved, the overall length and volume of the silencer are reduced, and the advantages of the short channel and small volume of the metamaterial silencer are ensured, so that it can be widely used when space is limited.

[0034] In this embodiment, the low-frequency muffler module includes nine low-frequency muffler channels, and the medium-frequency muffler module includes nine medium-frequency muffler channels, which are arranged in three rows and three columns, and the low-frequency muffler channels and the medium-frequency muffler channels are connected one by one. Correspondingly, the transition section 200 includes nine wind guide modules 1 arranged in the same manner, such as Figure 1-Figure 5 As shown, the outer frame 11 of each air guide module 1 is a hollow rectangular parallelepiped, and the side walls of adjacent outer frames 11 are fixedly connected. The inner frame 12 of each air guide module 1 is arranged in the outer frame 11 and is of the same length as the outer frame 11. The end of the inner frame 12 facing away from the main section 100 is circumferentially fixedly connected to the end of the outer frame 11 facing away from the main section 100. The end of the inner frame 12 facing the main section 100 is flush with the end of the outer frame 11 facing the main section 100. In the direction toward the main section 100, the inner diameter of the inner frame 12 gradually decreases, that is, the distance between the inner frame 12 and the outer frame 11 gradually increases. The baffle is connected to the inner frame 12 and the end of the outer frame 11 facing the main section 100, and the three enclose a cavity that cooperates with the elastic membrane 13 on the inner frame 12 to reduce noise.

[0035] The inner diameter of the inner frame 12 at one end facing the main section 100 is consistent with the size of the low-frequency silencer channel and the medium-frequency silencer channel, and is interconnected, and the inner diameter at the end facing away from the main section 100 is larger than the size of the low-frequency silencer channel and the medium-frequency silencer channel, so that the inner frame 12 forms a bell-shaped shape. When the transition section 200 is connected to the windward side of the main section 100, the bell-shaped shape of the inner frame 12 can smoothly guide the airflow into the low-frequency silencer channel and the medium-frequency silencer channel of the main section 100, reducing wind resistance; when the transition section 200 is connected to the leeward side of the main section 100, the bell-shaped shape of the inner frame 12 can improve the stability of the outgoing airflow. In this embodiment, the windward side and the leeward side of the main section 100 are both connected to a transition section 200, and the two transition sections 200 are configured in the same manner, so that the airflow can be smoothly introduced from the transition section 200 on the windward side into the main section 100, and the stability of the airflow discharged from the main section 100 can be improved. At the same time, when the airflow passes through the two transition sections 200, the thin film resonator of the wind guide module 1 is used to silence the high-frequency noise. According to the specific settings of the low-frequency silencer channel of the low-frequency silencer module and the intermediate-frequency silencer channel of the intermediate-frequency silencer module, the number and position of the wind guide module 1 in the transition section 200 are adjusted accordingly. The transition section 200 can be set only on one side of the main section 100, and the volume of the cavity can be appropriately adjusted according to the frequency of the noise to be eliminated. The low-frequency silencer module and the intermediate-frequency silencer module of the metamaterial structure are mature existing technologies, and their specific structures and working principles are not repeated here.

[0036] Optionally, the inner frame 12 is formed by connecting a plurality of side panels 121 end to end in sequence, the first end of each side panel 121 is connected to the first end of the outer frame 11, the second end of each side panel 121 is connected to the shielding plate, and an elastic membrane 13 is fixed to each side panel 121. This arrangement simplifies the structural composition of the inner frame 12 and is easy to obtain and assemble.

[0037] like Figure 2 and Figure 4 As shown, in this embodiment, the inner frame 12 is formed by connecting four side panels 121 end to end in sequence, one end of each side panel 121 is connected to the edge of one end of the outer frame 11 away from the main section 100, and the other end extends toward the main section 100 to be flush with the outer frame 11 and connected to the shielding plate. Because the inner diameter of the inner frame 12 gradually decreases in the direction toward the main section 100, each side panel 121 is inclined to maintain a certain distance from the outer frame 11. The flat inclined surface can smoothly guide the airflow into the main section 100 when it is set on the windward side of the main section 100, and can guide the airflow to be discharged smoothly when it is set on the leeward side of the main section 100. As shown in the figure, the elastic membrane 13 is fixed to the same position on the four side panels 121. According to the actual application, the shape, size and number of the side panels 121 constituting the inner frame 12 can be adjusted.

[0038] Optionally, each side panel 121 is configured as an isosceles trapezoid, the upper bottom of each side panel 121 is connected to the shielding plate, the lower bottom of each side panel 121 is connected to the first end of the outer frame 11, and the waists of adjacent side panels 121 are connected. This configuration allows the side panels 121 to be uniformly manufactured and formed, and is easy to splice.

[0039] like Figure 4 and Figure 5 As shown, in the present embodiment, each side panel 121 is an identical isosceles trapezoid and has the same inclination angle relative to the outer frame 11, a lower base with a larger length is connected to the end of the outer frame 11 away from the main section 100, and an upper base with a smaller length faces the main section 100 and is connected to the shielding plate, so that the cross-section of the end of the inner frame 12 away from the main section 100 is a larger square, and the cross-section toward the end of the main section 100 is a smaller square.

[0040] Optionally, the angle between the side panel 121 and the outer frame 11 ranges from 10° to 25°. The inner cavity formed by connecting the side panels 121 end to end, the outer frame 11 and the shielding plate enclose a cavity. The size of the cavity volume is directly related to the frequency of noise elimination. The transition section 200 mainly eliminates the high-frequency part of the noise. The elastic membrane 13 is required to cooperate with the smaller cavity to form a thin film resonator that is effective for high-frequency noise. The angle between the side panel 121 and the outer frame 11 is set to the above range to ensure that the volume of the cavity is within a certain range, preventing the cavity volume from being too large and affecting the silencing effect of high-frequency noise.

[0041] like Figure 4 As shown, in this embodiment, the angle between the side panel 121 and the outer frame 11 is about 20°. Depending on the actual application, the angle between the two can also be set to any angle within the above range, such as 10°, 15°, 25°, etc.

[0042] Optionally, the width of the elastic membrane 13 accounts for 15%-30% of the width of the bottom of the side plate 121. The width of the elastic membrane 13 affects its frequency response and acoustic characteristics. A wider elastic membrane 13 usually has a lower resonance frequency, while a narrower elastic membrane 13 has a higher resonance frequency. The transition section 200 mainly eliminates the high-frequency part of the noise. Therefore, the width of the elastic membrane 13 should not be too large. Setting it within the above width range can ensure the silencing effect of the thin film resonator on high-frequency noise.

[0043] like Figure 5 As shown, in the present embodiment, the width of the elastic membrane 13 is approximately 30% of the lower bottom width of the trapezoidal side panel 121. Depending on the actual application, the width of the elastic membrane 13 can be appropriately adjusted within the above range. For example, the width of the elastic membrane 13 is 15%, 20%, 25%, etc. of the lower bottom width of the trapezoidal side panel 121.

[0044] Optionally, the air guide module 1 further includes a partition plate (not shown), which is disposed in the cavity, connecting the inner frame 12 and the outer frame 11, and dividing the cavity into a plurality of independent chambers. The partition plate is used to divide the cavity enclosed by the outer frame 11, the inner frame 12 and the shielding plate into a plurality of chambers, so that the elastic membrane 13 fixed on the inner frame 12 no longer corresponds to a cavity with a larger volume, but corresponds to a chamber with a smaller volume, so that the elastic membrane 13 and the chamber corresponding thereto form a new thin film resonator, and because the volume of the chamber is smaller than the volume of the entire cavity, the new thin film resonator formed by the elastic membrane 13 and the corresponding chamber can respond to noise in a higher frequency range, that is, the transition section 200 can eliminate high-frequency noise of a higher frequency.

[0045] like Figure 4 As shown, in this embodiment, the inner frame 12 is composed of four side panels 121 connected end to end, and a total of four partitions are provided. One end of each partition is connected to the intersection line between two adjacent side panels 121, and the other end is connected to the outer frame 11, so that the cavity is divided into four independent chambers. An elastic membrane 13 is fixed on each side panel 121, so that each elastic membrane 13 and the corresponding chamber behind it constitute a thin film resonator to mute the high-frequency noise in the airflow flowing through the air guide channel. According to the actual application, the number of partitions can be adjusted. For example, two partitions can be provided to divide the cavity into two independent chambers, or three partitions can be provided to divide the cavity into three independent chambers. The volume of each chamber can be equal or unequal.

[0046] Optionally, the outer frame 11 is formed by connecting a plurality of frame plates 111 end to end in sequence. This arrangement simplifies the structural composition of the outer frame 11, and the frame plates 111 are uniformly manufactured, which is easy to assemble.

[0047] like Figure 4 As shown, in this embodiment, the outer frame 11 is a hollow cuboid, which is formed by splicing four rectangular frame plates 111 end to end, and one end of the inner frame 12 is connected to the end of the frame plate 111 away from the main section 100. According to the required size of the outer frame 11, the shape, size and number of the frame plates 111 can be adjusted.

[0048] Optionally, the metamaterial muffler further includes a reinforcement plate 2, which is fixedly connected to the circumference of the transition section 200. The transition section 200 is formed by splicing a plurality of wind guide modules 1, and the reinforcement plate 2 is provided and connected to the circumference of the transition section 200, which can further strengthen the connection between the wind guide modules 1.

[0049] like Figure 1 As shown, the transition section 200 includes nine wind guide modules 1 in three rows and three columns, and reinforcement plates 2 are fixed to four sides of the transition section 200, namely, the upper, lower, left and right sides.

[0050] Optionally, a mounting flange 3 is fixed to one end of the transition section 200 away from the main section 100. The mounting flange 3 is pre-connected to the transition section 200, and when the metamaterial muffler is fixed, it can be fixed to a desired position with the help of the mounting flange 3, saving installation time.

[0051] like Figure 1 As shown, transition sections 200 are connected to both ends of the main section 100, and mounting flanges 3 are fixed to the ends of the two transition sections 200 away from the main section 100. Mounting holes are pre-opened on the mounting flanges 3 to facilitate the installation of the metamaterial silencer by passing bolts through the mounting holes.

[0052] Optionally, a connecting flange 4 is fixed to at least one end of the main section 100, and the transition section 200 is connected to the main section 100 via the connecting flange 4. The main section 100 and the transition section 200 are connected by a flange, which is convenient for disassembly and has a sufficiently high connection strength.

[0053] like Figure 1 As shown, connecting flanges 4 are fixed to opposite ends of the main body section 100 , and the two transition sections 200 are fixed to the two ends of the main body section 100 through the connecting flanges 4 .

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A metamaterial muffler, characterized in that: include: A main body section, the main body section includes a low-frequency muffler module and a medium-frequency muffler module connected, the low-frequency muffler module is provided with a plurality of low-frequency muffler channels, the medium-frequency muffler module is provided with a plurality of medium-frequency muffler channels, and the plurality of low-frequency muffler channels and the plurality of medium-frequency muffler channels are connected one by one; A transition section, at least one end of the main section is connected to the transition section, the transition section comprises a plurality of wind guide modules, the plurality of wind guide modules are spliced ​​with each other and are arranged one by one corresponding to the plurality of low-frequency silencer channels; Each of the air guide modules comprises: An outer frame, wherein the outer frame is hollow; An inner frame, the inner frame is arranged in the outer frame, the inner frame is hollow to form an air guide channel, a first end of the inner frame is circumferentially fixedly connected to a first end of the outer frame, a second end of the inner frame is flush with a second end of the outer frame, and an inner diameter of the inner frame gradually decreases in a direction toward the second end thereof, an elastic film is fixed on an inner wall of the inner frame, and the second end of the inner frame is arranged toward the main body segment; A shielding plate is provided at the second end of the inner frame to block the space between the inner frame and the outer frame, so that the inner frame, the outer frame and the shielding plate enclose a cavity.

2. The metamaterial muffler according to claim 1, characterized in that: The inner frame is formed by connecting a plurality of side panels end to end in sequence, the first end of each side panel is connected to the first end of the outer frame, the second end of each side panel is connected to the shielding plate, and the elastic membrane is fixed to each side panel.

3. The metamaterial muffler according to claim 2, characterized in that: Each of the side panels is configured as an isosceles trapezoid, the upper base of each of the side panels is connected to the shielding plate, the lower base of each of the side panels is connected to the first end of the outer frame, and the waists of adjacent side panels are connected.

4. The metamaterial muffler according to claim 3, characterized in that: The included angle between the side plate and the outer frame ranges from 10° to 25°.

5. The metamaterial muffler according to claim 3, characterized in that: The width of the elastic film accounts for 15%-30% of the width of the lower bottom of the side plate.

6. The metamaterial muffler according to any one of claims 1 to 5, characterized in that: The wind guide module also includes: A partition plate is disposed in the cavity, connecting the inner frame and the outer frame, and dividing the cavity into a plurality of independent chambers.

7. The metamaterial muffler according to any one of claims 1 to 5, characterized in that: The outer frame is formed by connecting a plurality of frame plates end to end in sequence.

8. The metamaterial muffler according to any one of claims 1 to 5, characterized in that: Also includes: A reinforcing plate is fixedly connected to the circumference of the transition section.

9. The metamaterial muffler according to any one of claims 1 to 5, characterized in that: A mounting flange is fixed to one end of the transition section away from the main body section.

10. The metamaterial muffler according to any one of claims 1 to 5, characterized in that: A connecting flange is fixed to at least one end of the main body section, and the transition section is connected to the main body section via the connecting flange.

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