Refrigerator, acoustic metamaterial noise reduction device and method for designing acoustic metamaterial structure

Abstract

The invention relates to the technical field of acoustic metamaterials, in particular to a refrigerator, an acoustic metamaterial noise reduction device and a method for designing an acoustic metamaterial structure. The method for designing the acoustic metamaterial structure comprises the following steps: S100, acquiring a noise spectrum of operation noise of target equipment and an available space volume of an installation space of the acoustic metamaterial structure; and S200, acquiring a target absorption spectrum of the acoustic metamaterial structure capable of achieving a preset noise reduction effect for the noise spectrum under the condition that the volume of the acoustic metamaterial structure is not greater than the volume of the available space. And S300, obtaining a design model of the acoustic material structure at least according to the available space volume and the target absorption spectrum. According to the acoustic metamaterial noise reduction device, broadband noise reduction can be achieved under the spatial constraint requirement, and then the purpose of improving the noise reduction effect of the acoustic metamaterial noise reduction device can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of acoustic metamaterials, and in particular to a refrigerator, an acoustic metamaterial noise reduction device and a method for designing an acoustic metamaterial structure. Background Art

[0002] At present, in order to solve the heat dissipation and noise reduction problems of refrigerators, we have proposed to set a heat dissipation window on the compressor compartment of the refrigerator, and set an acoustic metamaterial noise reduction device on the heat dissipation window to promote the heat dissipation airflow to flow through the heat dissipation channel of the acoustic metamaterial noise reduction device, and at the same time, the noise reduction channel formed on the channel wall of the heat dissipation channel resonates and reduces the noise mixed in the heat dissipation airflow, so as to solve the heat dissipation and noise reduction problems of the refrigerator at the same time.

[0003] When designing the metamaterial structure of the metamaterial noise reduction device, the prior art uses the 1 / 4 wavelength tube theory to calculate the 1 / 4 wavelength tube length corresponding to each target noise frequency, then selects different 1 / 4 wavelength tubes according to each of the 1 / 4 wavelength tube lengths, and combines the 1 / 4 wavelength tubes of different lengths in the applicable space to form a metamaterial structure. However, the metamaterial structure formed by the combination of 1 / 4 wavelength tubes of different lengths is only applicable to the narrowband noise spectrum composed of discrete finite target noise frequencies, which brings the disadvantages of the metamaterial structure such as narrow action frequency band and sensitivity to incident angle, which has become a key bottleneck problem restricting the development and application of acoustic metamaterial technology in the refrigerator field.

[0004] Therefore, the prior art urgently needs a method for improving the working bandwidth of an acoustic metamaterial noise reduction device, so as to develop a design method for a metamaterial structure with good noise reduction effect on broadband noise frequencies. Summary of the invention

[0005] In view of the above problems, the present invention is proposed to provide a refrigerator, an acoustic metamaterial noise reduction device and a method for designing an acoustic metamaterial structure that overcome the above problems or at least partially solve the above problems, which can solve the problem of narrow action band of the metamaterial structure formed by the combination of 1 / 4 wavelength tubes of different lengths, and achieve the purpose of improving the noise reduction effect of the acoustic metamaterial noise reduction device.

[0006] In one aspect, the present invention provides a method for designing an acoustic metamaterial structure, comprising:

[0007] S100, obtaining a noise spectrum of operating noise of a target device and an available space volume of an installation space of an acoustic metamaterial structure;

[0008] S200, obtaining a target absorption spectrum of the acoustic metamaterial structure that can achieve a preset noise reduction effect for the noise spectrum under the condition that the volume of the acoustic metamaterial structure is not greater than the volume of the available space;

[0009] S300, obtaining a design model of the acoustic material structure at least according to the available space volume and the target absorption spectrum.

[0010] Optionally, step S300 includes:

[0011] S301, creating a simulation model of the acoustic metamaterial structure at least according to the available space volume;

[0012] S302, obtaining a simulated absorption spectrum of the simulation model under the noise spectrum condition;

[0013] S303, determining whether the difference between the simulated absorption spectrum of the simulation model and the target absorption spectrum of the acoustic metamaterial structure meets a preset condition,

[0014] If so, the simulation model is used as the design model of the acoustic material structure.

[0015] Optionally, step S301 further includes: extracting sensitive parameters that affect the simulated absorption spectrum in the simulation model; and

[0016] After determining whether the difference between the simulated absorption spectrum of the simulation model and the target absorption spectrum of the acoustic metamaterial structure meets a preset condition, the method further includes:

[0017] If not, after adjusting the sensitive parameters of the simulation model, steps S302 and S303 are performed again.

[0018] Optionally, step S200 includes:

[0019] Extracting a target frequency value from the noise spectrum;

[0020] Calculate the absorption frequency value based on the target frequency value, the available space volume and the preset noise reduction effect;

[0021] The target absorption spectrum is obtained according to the noise spectrum and the absorption frequency value.

[0022] Optionally, the extracting the target frequency value in the noise spectrum includes:

[0023] Extracting a preset multiple noise spectrum of the noise spectrum;

[0024] At least a peak noise frequency value corresponding to the maximum sound pressure level amplitude in the preset multiple noise spectrum is extracted, and the peak noise frequency value is used as the target frequency value.

[0025] Optionally, the extracting the target frequency value in the noise spectrum includes:

[0026] At least a given noise frequency value emitted by a preset noise source is extracted from the noise spectrum, and the given noise frequency value is used as the target frequency value.

[0027] Optionally, the creating a simulation model of the acoustic metamaterial structure includes:

[0028] According to the 1 / 4 wavelength tube principle, at least one resonant cavity having a length corresponding to the target frequency value is generated in the simulation model; and / or

[0029] According to the resonant cavity principle, at least one resonant cavity having an opening size corresponding to the target frequency value is generated in the simulation model.

[0030] Optionally, the creating a simulation model of the acoustic metamaterial structure includes:

[0031] generating an airflow channel and at least two resonance cavities in the simulation model, wherein the inlet of the resonance cavity is located on the channel wall of the airflow channel; and

[0032] The sensitive parameter is at least one of the following:

[0033] The shape of the simulation model, the size of the simulation model, the material of the simulation model, the sealing of the simulation model, the position of the inlet of the resonant cavity on the channel wall of the airflow channel, the shape of the resonant cavity, the length of the resonant cavity, the position of the resonant cavity relative to the airflow channel, and the number of the resonant cavities.

[0034] Optionally, step S302 includes:

[0035] The COMSOL software is used to perform theoretical simulation of noise reduction of the simulation model to obtain an insertion loss spectrum under the noise spectrum condition, and the insertion loss spectrum is used as the simulated absorption spectrum.

[0036] Optionally, after step S300, the method further includes:

[0037] S400, manufacturing the acoustic metamaterial structure according to the design model;

[0038] S500, installing the acoustic metamaterial structure in the acoustic metamaterial structure installation space of the target device, and detecting the operating noise of the target device to generate a noise reduction spectrum;

[0039] S600: Compare the noise reduction spectrum with the noise spectrum.

[0040] On the other hand, the present invention also provides an acoustic metamaterial noise reduction device, comprising:

[0041] An acoustic metamaterial structure, wherein at least two resonant cavities are formed on the acoustic metamaterial structure, and a design model for manufacturing the acoustic metamaterial structure is obtained by at least any of the methods described above;

[0042] A connection structure is configured to enable installation of the acoustic metamaterial structure within an installation space on a target device.

[0043] Optionally, a straight through airflow channel is also formed on the acoustic material structure, and the inlet of each resonance cavity is located on the channel wall of the airflow channel.

[0044] Optionally, at least a portion of at least one of the resonant cavities extends along a straight line, a broken line or a curved line.

[0045] Optionally, the thickness d of the acoustic material structure satisfies the following formula:

[0046]

[0047] Where λ is the wavelength of sound waves in air;

[0048] A(λ) is the target absorption spectrum.

[0049] Optionally, the thickness d of the acoustic material structure satisfies the following formula:

[0050]

[0051] Where λ is the wavelength of sound waves in air;

[0052] A(λ) is the target absorption spectrum;

[0053] E(λ) is the noise spectrum;

[0054] ΔSPL is the preset noise reduction effect.

[0055] In addition, the present invention also provides a refrigerator, comprising:

[0056] A compressor compartment, wherein a heat dissipation window is formed on at least one side compartment wall and / or a bottom plate of the compressor compartment;

[0057] The acoustic metamaterial noise reduction device described in any of the above items, wherein the acoustic metamaterial noise reduction device is arranged on the heat dissipation window.

[0058] In the method for designing an acoustic metamaterial structure of the present invention, a method for designing an acoustic metamaterial structure that can achieve broadband noise reduction under space constraint requirements is provided. The design model of the acoustic metamaterial structure obtained by the above method can achieve a target absorption spectrum that meets the preset noise reduction effect under space constraint conditions. Since the target absorption spectrum covers all frequency bands of the target device operating noise; therefore, the design model of the acoustic metamaterial structure obtained by the above method can reduce noise in all frequency bands of the target device operating noise under space constraint conditions, thereby solving the problem of narrow action band of the metamaterial structure formed by the combination of 1 / 4 wavelength tubes of different lengths in the prior art, improving the working bandwidth of frequency reduction, that is, achieving broadband noise reduction, and thus achieving the purpose of improving the noise reduction effect of the acoustic metamaterial noise reduction device. After the acoustic metamaterial structure prepared by the method is installed on the target device, the sound pressure amplitude of the spectrum emitted by the target device can be made close to equal, that is, the spectrum line after noise reduction can be made smoother, thereby significantly improving the noise reduction effect.

[0059] Based on the following detailed description of specific embodiments of the present invention in conjunction with the accompanying drawings, those skilled in the art will become more aware of the above and other objects, advantages and features of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Hereinafter, some specific embodiments of the present invention will be described in detail in an exemplary and non-limiting manner with reference to the accompanying drawings. The same reference numerals in the accompanying drawings indicate the same or similar components or parts. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the accompanying drawings:

[0061] Figure 1 is a schematic flow chart of a method for designing an acoustic metamaterial structure in one embodiment of the present invention;

[0062] Figure 2 is a schematic flow chart of a method for designing an acoustic metamaterial structure in one embodiment of the present invention;

[0063] Figure 3 is a schematic flow chart of a method for designing an acoustic metamaterial structure in one embodiment of the present invention;

[0064] Figure 4 is a noise spectrum diagram of a target device without an acoustic metamaterial noise reduction device installed in one embodiment of the present invention;

[0065] Figure 5 is an insertion loss spectrum diagram according to one embodiment of the present invention;

[0066] Figure 6 is a comparison diagram of a noise reduction spectrum and a noise spectrum according to an embodiment of the present invention;

[0067] Figure 7is a schematic structural diagram of an acoustic metamaterial noise reduction device according to an embodiment of the present invention;

[0068] Figure 8 is a schematic structural diagram of an acoustic metamaterial noise reduction device according to an embodiment of the present invention;

[0069] Fig. 9 is a schematic structural diagram of an acoustic metamaterial noise reduction device according to an embodiment of the present invention;

[0070] Fig.10 is a schematic structural diagram of an acoustic metamaterial noise reduction device according to an embodiment of the present invention;

[0071] Fig.11 is a schematic structural diagram of a refrigerator according to one embodiment of the present invention. DETAILED DESCRIPTION

[0072] Refer to the following Figures 1 to 11 To describe the refrigerator, acoustic metamaterial noise reduction device and method for designing acoustic metamaterial structure of the embodiment of the present invention. In the description of this embodiment, it should be understood that the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features, that is, include one or more of the features. In the description of the present invention, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. When a feature "includes or contains" one or some of the features it covers, unless otherwise specifically described, this indicates that other features are not excluded and may further include other features.

[0073] Unless otherwise clearly defined and limited, the terms "set", "install", "connect", "connect", "fix", "couple" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. A person skilled in the art should be able to understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0074] In addition, in the description of this embodiment, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through another feature between them. That is, in the description of this embodiment, the first feature being "above", "above", and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature being "below", "below", or "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0075] In the description of the present embodiment, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" 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 representation of the above terms does 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.

[0076] Figure 1 is a schematic flow chart of a method for designing an acoustic metamaterial structure, such as Figure 1 As shown, and refer to Figures 2 to 3 , an embodiment of the present invention provides a method for designing an acoustic metamaterial structure.

[0077] A method for designing an acoustic metamaterial structure comprises the following steps:

[0078] S100: Acquire a noise spectrum of operating noise of a target device and an available space volume of an installation space of an acoustic metamaterial structure.

[0079] S200, obtaining a target absorption spectrum of the acoustic metamaterial structure that can achieve a preset noise reduction effect for the noise spectrum under the condition that the volume of the acoustic metamaterial structure is not greater than the volume of the available space.

[0080] S300, obtaining a design model of the acoustic material structure at least according to the available space volume and the target absorption spectrum.

[0081] Specifically, firstly, step S100 is performed to obtain the noise spectrum and the available space volume. Then, step S200 is performed to obtain the target absorption spectrum of the acoustic metamaterial structure according to the noise spectrum and the preset noise reduction effect under the condition that the volume of the acoustic metamaterial structure is not greater than the available space volume; and step S300 is performed to obtain the design model of the acoustic material structure according to at least the available space volume and the target absorption spectrum.

[0082] In this embodiment, a method for designing an acoustic metamaterial structure that can achieve broadband noise reduction under space constraints is provided. The design model of the acoustic metamaterial structure obtained by the above method can achieve the target absorption spectrum under space constraints, thereby achieving the preset noise reduction effect on the target device.

[0083] Furthermore, since the noise spectrum and the target absorption spectrum cover all frequency bands of the target device operating noise, the design model of the acoustic metamaterial structure can reduce the noise of all frequency bands of the target device operating noise under the condition of space constraints, thereby solving the problem of narrow action band of the metamaterial structure formed by the combination of 1 / 4 wavelength tubes of different lengths in the prior art, improving the working bandwidth of the acoustic metamaterial structure, realizing broadband noise reduction, and thus achieving the purpose of improving the noise reduction effect of the acoustic metamaterial noise reduction device.

[0084] Furthermore, after the acoustic metamaterial structure prepared by this method is installed in the target device, the sound pressure amplitude of the noise spectrum emitted by the target device can be made close to equal, that is, the lines of the noise spectrum after noise reduction can be made smoother, thereby significantly improving the noise reduction effect.

[0085] like Figure 2 As shown, in some embodiments of the present invention, step S300 includes the following steps:

[0086] S301: Create a simulation model of the acoustic metamaterial structure at least according to the available space volume.

[0087] S302, obtaining a simulated absorption spectrum of the simulation model under a noise spectrum condition.

[0088] S303, determining whether the difference between the simulated absorption spectrum of the simulation model and the target absorption spectrum of the acoustic metamaterial structure meets a preset condition, and if so, using the simulation model as a design model of the acoustic metamaterial structure.

[0089] This embodiment provides a specific method for obtaining a design model of an acoustic material structure, which has the advantage of being simple and easy to operate.

[0090] like Figure 3 As shown, in some embodiments of the present invention, step S301 further includes the following steps: extracting sensitive parameters that affect the simulated absorption spectrum in the simulation model.

[0091] After determining whether the difference between the simulated absorption spectrum of the simulation model and the target absorption spectrum of the acoustic metamaterial structure meets the preset conditions, the following steps are also included: if not, after adjusting the sensitive parameters of the simulation model, steps S302 and S303 are performed again.

[0092] In this embodiment, in step S303, after determining whether the difference between the simulated absorption spectrum of the simulation model and the target absorption spectrum of the acoustic metamaterial structure meets the preset conditions, if the preset conditions are not met, the sensitive parameters of the simulation model are adjusted, and then steps S302 and S303 are executed until the difference between the simulated absorption spectrum and the target absorption spectrum meets the preset conditions. In other words, step S301 obtains the initial simulation model of the acoustic metamaterial structure. If the difference between the simulated absorption spectrum of the initial simulation model and the target absorption spectrum does not meet the preset conditions, the sensitive parameters of the simulation model are adjusted until the difference between the simulated absorption spectrum of the adjusted simulation model and the target absorption spectrum meets the preset conditions. This embodiment provides a scientific and effective way to correct the simulation model, which has the advantage of being simple and easy to operate.

[0093] In some embodiments of the present invention, in step S200, the target absorption spectrum is calculated using the following formula:

[0094]

[0095]

[0096] Wherein, d is the thickness of the acoustic material structure, λ is the wavelength of the sound wave in the air; A(λ) is the target absorption spectrum; E(λ) is the noise spectrum; ΔSPL is the preset noise reduction effect.

[0097] Specifically, regarding the above formula 1: each wavelength of noise frequency can be reduced, but the limit of noise reduction is determined by the spatial thickness (available space volume) of the noise reduction component (i.e., the metamaterial structure), so noise reduction needs to be combined with the actual size of the actual metastructure. For example, when the target device is a refrigerator, the limit of noise reduction for the refrigerator is determined by the noise reduction space boundary of the refrigerator. Specifically, the limit of noise reduction is determined by the maximum available space volume at the ventilation window position of the compressor compartment. In other words, the volume of the acoustic metamaterial structure is not greater than the available space volume of the acoustic metamaterial structure installation space.

[0098] Regarding the above formula 2: The noise spectrum is a fixed value. The method for obtaining the noise spectrum (i.e., the original noise spectrum) is to collect and test it in a noise room. The available space volume is a fixed value. The available space volume refers to the maximum external dimensions of the metastructure. Since the thickness of the acoustic metamaterial structure is generally 1-5mm, the maximum available volume of the inner cavity of the acoustic metamaterial structure is a fixed value. Based on the noise spectrum and the available space volume, combined with the above formula 2, the target absorption spectrum (absorption performance curve) that can achieve the preset noise reduction effect can be obtained.

[0099] In some embodiments of the present invention, step S200 includes the following steps:

[0100] Step S201, extracting a target frequency value from a noise spectrum.

[0101] Step S202: Calculate the absorption frequency value based on the target frequency value, the available space volume and the preset noise reduction effect.

[0102] Step S203, obtaining a target absorption spectrum according to the noise spectrum and the absorption frequency value.

[0103] In this embodiment, a specific step of obtaining a target absorption spectrum is provided: first, a target frequency value within a noise frequency range corresponding to a noise spectrum is obtained, and the target frequency value is a single-point frequency value or a multi-point frequency value; then, an absorption frequency value based on the target frequency value is calculated according to the target frequency value, the available space volume, and the preset noise reduction effect; then, according to the remaining frequency values ​​within the noise frequency range corresponding to the noise spectrum and the sound pressure amplitude corresponding to the remaining frequency values, the absorption frequency value corresponding to the target frequency value, and the preset noise reduction effect, the absorption frequency values ​​corresponding to the remaining frequency values ​​within the above noise frequency range are set, thereby obtaining a target absorption spectrum based on the above noise frequency range, and the target absorption spectrum is a collection of multiple absorption frequency values. This embodiment has the advantages of simple steps and easy operation, thereby making the design efficiency of the acoustic metamaterial structure high.

[0104] In some embodiments of the present invention, the step of extracting the target frequency value from the noise spectrum includes: extracting a preset multiple noise spectrum of the noise spectrum; extracting at least a peak noise frequency value corresponding to the maximum sound pressure level amplitude in the preset multiple noise spectrum, and taking the peak noise frequency value as the target frequency value.

[0105] Further, in some embodiments of the present invention, the predetermined octave frequency is 1 / 3 octave frequency. In some alternative embodiments, the predetermined octave frequency may be 1 / 6, 1 / 12 or other octave frequency.

[0106] For example: Figure 4 As shown, Figure 4 This is the 1 / 3 spectrum of a refrigerator. The peak noise frequency values ​​are 250Hz and 500Hz. You can choose 250Hz and 500Hz as the target frequency values. The target frequency value is not fixed, and the target frequency values ​​of different target devices may be different.

[0107] In some embodiments of the present invention, the extracting of the target frequency value in the noise spectrum includes: extracting a given noise frequency value emitted by a preset noise source at least in the noise spectrum, and using the given noise frequency value as the target frequency value.

[0108] For example, the preset noise source is a compressor, and the given noise frequency value emitted by the compressor is used as the target frequency value. The given noise frequency value emitted by the compressor is the inherent noise frequency, for example, the inherent noise frequency is 630 Hz, and 630 Hz is used as the target frequency value.

[0109] In some preferred embodiments of the present invention, the method of extracting the target frequency value in the noise spectrum includes: extracting a preset multiple noise spectrum of the noise spectrum; extracting at least a peak noise frequency value corresponding to the maximum sound pressure level amplitude in the preset multiple noise spectrum, and taking the peak noise frequency value as the target frequency value; and extracting at least a given noise frequency value emitted by a preset noise source in the noise spectrum, and taking the given noise frequency value as the target frequency value.

[0110] In this embodiment, the target frequency value includes the peak noise frequency value and the given noise frequency value emitted by the preset noise source. Therefore, compared with the method of using only one of the peak noise frequency value or the given noise frequency value as the target frequency value, the number of target frequency values ​​in this embodiment is greater, so the number of absorption frequency values ​​calculated based on the target frequency value is greater, and the number of absorption frequency values ​​that need to be set is less, which improves the efficiency of obtaining the target absorption spectrum, and the obtained target absorption spectrum is more reasonable, so that the design model can be more reasonable, which is conducive to further improving the effect of broadband noise reduction.

[0111] In some embodiments of the present invention, creating a simulation model of an acoustic metamaterial structure includes: generating at least one resonant cavity having a length corresponding to a target frequency value in the simulation model according to a 1 / 4 wavelength tube principle.

[0112] Specifically, in step S301, according to the 1 / 4 wavelength tube principle, the length of the resonant cavity corresponding to the target frequency value is calculated, and one or more resonant cavities with lengths corresponding to the target frequency value are generated in the simulation model to better reduce the noise of the target frequency value.

[0113] In some embodiments of the present invention, creating a simulation model of an acoustic metamaterial structure includes: generating at least one resonant cavity having an opening size corresponding to a target frequency value in the simulation model according to a resonant cavity principle.

[0114] Specifically, the opening size of the resonant cavity refers to the inlet aperture of the resonant cavity. In step S301, according to the resonant cavity principle, at least one resonant cavity with an opening size corresponding to the target frequency value is generated in the simulation model to better reduce noise of the target frequency value.

[0115] In some embodiments of the present invention, creating a simulation model of an acoustic metamaterial structure includes: generating at least one resonant cavity having a length corresponding to a target frequency value in the simulation model according to the 1 / 4 wavelength tube principle; and generating at least one resonant cavity having an opening size corresponding to the target frequency value in the simulation model according to the resonant cavity principle.

[0116] In this embodiment, the opening size of the resonant cavity refers to the inlet aperture of the resonant cavity. In step S301, the length and opening size of the resonant cavity in the simulation model are designed according to the 1 / 4 wavelength tube principle and the resonant cavity principle, so that the impedance is approximately matched in all frequency bands of the noise spectrum to better achieve broadband noise reduction effect. That is to say, this embodiment controls the distribution of frequency (based on the 1 / 4 wavelength tube theory) and the distribution of resonance intensity (adjusting the inlet size of the resonant cavity) to make the impedance approximately match in all frequency bands of the noise spectrum to better achieve broadband noise reduction effect.

[0117] like Figure 7 As shown, in some embodiments of the present invention, creating a simulation model of an acoustic metamaterial structure includes: generating an airflow channel and at least two resonant cavities in the simulation model, wherein the inlet of the resonant cavity is located on the channel wall of the airflow channel.

[0118] When in use, the noise first enters the air flow channel and then enters the resonance cavity through the inlet of the resonance cavity, thereby achieving noise reduction.

[0119] In some embodiments of the present invention, the sensitive parameter is at least one of the following: the shape of the simulation model, the size of the simulation model, the material of the simulation model, the sealing of the simulation model, the position of the inlet of the resonant cavity on the channel wall of the airflow channel, the shape of the resonant cavity, the length of the resonant cavity, the position of the resonant cavity relative to the airflow channel, and the number of resonant cavities.

[0120] In some optional embodiments of the present invention, step S302 includes: using COMSOL software to perform theoretical simulation of simulation model noise reduction, obtain an insertion loss spectrum under noise spectrum conditions, and use the insertion loss spectrum as a simulated absorption spectrum.

[0121] COMSOL software is a simulation software that can realize all physical fields and the entire process from modeling to simulation to post-processing and even optimization in one interface. Compared with other software, using COMSOL software can improve the production effect of design models.

[0122] like Figure 5 As shown, in some embodiments of the present invention, the noise reduction working frequency band of the design model covers the frequency band of 230-8000 Hz. The average noise reduction effect in the main working frequency band is about 5dB(A).

[0123] In some embodiments of the present invention, after step S300, the method for designing an acoustic metamaterial structure further comprises the following steps:

[0124] S400, fabricating acoustic metamaterial structures according to the design model.

[0125] S500: Install an acoustic metamaterial structure in an acoustic metamaterial structure installation space of a target device, and detect operating noise of the target device to generate a noise reduction spectrum.

[0126] S600, comparison of noise reduction spectrum and noise spectrum.

[0127] In this embodiment, an acoustic metamaterial structure is manufactured according to a design model; the acoustic metamaterial structure is installed on a target device, and then the operating noise of the target device is obtained to obtain a noise reduction spectrum; then the noise reduction spectrum and the noise spectrum are combined to verify whether the noise reduction effect of the acoustic metamaterial structure has achieved the preset noise reduction effect. Therefore, this embodiment provides a specific method for verifying whether the physical acoustic metamaterial structure can achieve the preset noise reduction effect, which is simple and easy to operate; by executing the above steps, it is easy to ensure the actual acoustic quality of the target device.

[0128] In some embodiments of the present invention, the target device is a refrigeration device, such as a refrigerator or freezer. In some alternative embodiments, the target device may also be other devices that require noise reduction.

[0129] like Figure 7-10 As shown, the present invention further provides an acoustic metamaterial noise reduction device 100, comprising: an acoustic metamaterial structure and a connection structure.

[0130] At least two resonant cavities 103 are formed on the acoustic metamaterial structure, and the design model for manufacturing the acoustic metamaterial structure is obtained by at least one of the methods in the above embodiments.

[0131] The connection structure is configured to enable installation of the acoustic metamaterial structure within a mounting space on a target device.

[0132] When in use, the acoustic metamaterial noise reduction device 100 is installed on a target device for noise reduction. Specifically, the acoustic metamaterial structure is installed on the target device through a connecting structure.

[0133] In this embodiment, the acoustic metamaterial noise reduction device can achieve broadband noise reduction for the target device, thereby having a good noise reduction effect on the target device, thereby improving the user experience.

[0134] In some embodiments of the present invention, a straight through airflow channel 101 is further formed on the acoustic material structure, and the inlet 102 of each resonance cavity 103 is located on the channel wall of the airflow channel 101 .

[0135] Specifically, the inlet 102 of the resonant cavity 103 is in communication with the airflow channel 101. When in use, noise enters the interior of the resonant cavity through the opening on the wall of the airflow channel to achieve noise reduction.

[0136] Preferably, the diameter of the airflow channel is 10 to 200 mm. For example, the diameter of the airflow channel is 10 mm, 20 mm, 30 mm, 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, 100 mm, 120 mm, 150 mm, 180 mm or 200 mm.

[0137] Further preferably, the diameter of the air flow channel is 80 mm.

[0138] In some embodiments of the present invention, the acoustic material structure is an irregular trapezoid, and its lateral dimension is about 180 mm*180 mm.

[0139] In some embodiments of the present invention, at least part of at least one resonant cavity extends along a straight line.

[0140] In some embodiments of the present invention, at least a portion of at least one resonant cavity extends along a fold line.

[0141] In some embodiments of the present invention, at least a portion of at least one resonant cavity extends along a curve.

[0142] In some embodiments of the invention, at least one resonant cavity has a labyrinthine structure.

[0143] In this embodiment, compared with the resonant cavity of the acoustic streaming structure, the honeycomb structure or the straight tube structure, the maze structure can arrange as many resonant cavities as possible, and the depth of the resonant cavity is deeper, which can significantly extend the propagation path of the sound, forming an acoustic superstructure, thereby further enhancing the noise reduction effect of the acoustic metamaterial noise reduction device.

[0144] Furthermore, the maze-like structure is a linear maze-like structure, a curved maze-like structure, or an irregular maze-like structure.

[0145] In some optional embodiments of the present invention, the thickness d of the acoustic material structure satisfies the following formula:

[0146]

[0147] Among them, λ is the wavelength of sound wave in air; A(λ) is the absorption spectrum of the target.

[0148] In some optional embodiments of the present invention, the thickness d of the acoustic material structure satisfies the following formula:

[0149]

[0150] Among them, λ is the wavelength of sound waves in air; A(λ) is the target absorption spectrum; E(λ) is the noise spectrum; ΔSPL is the preset noise reduction effect.

[0151] In some embodiments of the present invention, the surface of the acoustic metamaterial structure is covered with a layer of resistive sound absorbing material to increase the resistivity of the acoustic metamaterial structure.

[0152] In some embodiments of the present invention, the acoustic metamaterial structure is a sound absorbing metamaterial.

[0153] The sound-absorbing metamaterial (MAT metamaterial, MAT is the abbreviation of Metamaterial Absorption Technology) uses a synthetic material with high sound absorption efficiency, and there is a complex maze pattern structure on it. Each maze channel can absorb specific frequencies, and its sound absorption efficiency is as high as 99%. In addition, compared with general sound-absorbing materials, the chemical properties of sound-absorbing metamaterials are more stable, safer, odorless, elastic, fire-retardant, mildew-proof and anti-bacterial, and have a good feel and weight.

[0154] like Figure 7-11 As shown, the present invention further provides a refrigerator, which includes a compressor compartment 300 and an acoustic metamaterial noise reduction device 100. The acoustic metamaterial noise reduction device is the acoustic metamaterial noise reduction device 100 as described in any of the above embodiments.

[0155] A heat dissipation window is formed on at least one side of the compartment wall and / or the bottom plate of the compressor compartment 300. The acoustic metamaterial noise reduction device 100 is disposed on the heat dissipation window.

[0156] Specifically, "a heat dissipation window is formed on at least one side of the warehouse wall and / or the bottom plate of the compressor warehouse" includes the following situations: ① A heat dissipation window is provided on at least one side of the warehouse wall of the compressor warehouse; ② Heat dissipation windows are provided on at least one side of the warehouse wall and the bottom plate of the compressor warehouse; ③ A heat dissipation window is formed on the bottom plate of the compressor warehouse.

[0157] When the refrigerator compressor is in operation, the noise in the compressor compartment 300 propagates from the inside to the outside. When passing through the acoustic metamaterial noise reduction device 100 located at the heat dissipation window, the noise enters the resonance cavity 103 through the opening on the wall of the air flow channel 101, thereby achieving noise reduction of the compressor compartment, and then achieving noise reduction of the entire refrigerator.

[0158] like Figure 6 As shown, by comparing the noise reduction spectrum of the refrigerator installed with the acoustic metamaterial noise reduction device and the noise spectrum of the refrigerator not installed with the acoustic metamaterial noise reduction device, it can be seen that by installing the acoustic metamaterial noise reduction device, the refrigerator can be subjected to broadband noise reduction, and the overall noise reduction amount of the refrigerator is 5dB.

[0159] Furthermore, in some embodiments of the present invention, a heat dissipation window is provided on at least one side of the compressor compartment 300 , and the acoustic metamaterial noise reduction device 100 is provided on the heat dissipation window. In other words, the acoustic metamaterial noise reduction device 100 is installed on the side wall of the compressor compartment 300 .

[0160] The resonant cavity 103 of the acoustic metamaterial structure includes at least one first resonant cavity 1031 and at least one second resonant cavity 1032. The inlet of the first resonant cavity 1031 faces downward, and the inlet of the second resonant cavity 1032 faces upward. The length of the first resonant cavity 1031 is greater than that of the second resonant cavity 1032.

[0161] When in use, dust is not easy to enter the first resonant cavity 1031, and the dust has little effect on the first resonant cavity 1031. In addition, since the main frequency of the compressor compartment 300 is low-frequency noise, based on the mechanism that the wavelength of low-frequency sound waves is longer than that of high-frequency sound waves, even if dust enters the second resonant cavity 1032, it will not have a significant impact on the noise reduction of the compressor. In addition, since the length of the second resonant cavity 1032 is short, it is relatively easy to clean and remove dust from the second resonant cavity 1032. Therefore, the present invention can minimize the impact of dust on the noise reduction effect during use, so that the acoustic metamaterial structure has a good noise reduction effect.

[0162] Furthermore, in some embodiments of the present invention, the inlet aperture of the first resonant cavity 1031 is smaller than the inlet aperture of the second resonant cavity 1032 .

[0163] In this embodiment, on the one hand, since the inlet of the first resonant cavity 1031 is mainly used to reduce the noise of low-frequency sound waves, and the inlet of the second resonant cavity 1032 is mainly used to reduce the noise of high-frequency sound waves, the inlet aperture of the first resonant cavity 1031 is smaller than the inlet aperture of the second resonant cavity 1032, which is more conducive to improving the noise reduction effect of the inlet of the first resonant cavity 1031 on low-frequency sound waves, and more conducive to improving the noise reduction effect of the inlet of the second resonant cavity 1032 on high-frequency sound waves, thereby improving the noise reduction effect on the compressor compartment 300, and then improving the noise reduction effect on the refrigerator, so as to further improve the user experience. On the other hand, this embodiment is more conducive to dust removal and cleaning of the second resonant cavity 1032.

[0164] In some embodiments of the present invention, the number of the first resonant cavities 1031 is greater than the number of the second resonant cavities 1032 .

[0165] Since the noise of the compressor compartment 300 is only low-frequency noise, this embodiment is more conducive to reducing the noise of low-frequency sound waves, thereby being more conducive to improving the noise reduction effect of the compressor compartment 300, and further improving the noise reduction effect of the refrigerator.

[0166] In some embodiments of the present invention, a notch 104 is formed on the cavity wall of two adjacent resonant cavities 103 to connect the two adjacent resonant cavities 103. In this embodiment, by providing the notch 104, the size of the resonant cavity can be changed.

[0167] Furthermore, the notch 104 is disposed on the cavity walls of the adjacent first resonant cavity 1031 and the second resonant cavity 1032 .

[0168] Furthermore, the notch 104 is disposed at the tail of the second resonant cavity 1032 , which is more advantageous in increasing the length of the first resonant cavity 1031 , thereby being more advantageous in reducing low-frequency noise.

[0169] In some optional embodiments of the present invention, an installation and assembly interface 130 for installing a ventilation grille is provided at the airflow channel 101. In this embodiment, the installation and assembly interface 130 is a snap-on structure, and the installation and assembly interface 130 is consistent with the existing interface, and is used to install the ventilation grille, thereby improving versatility and practicality, reducing costs, and can be used for refrigerators of different categories and models.

[0170] like Fig.11 As shown, in some embodiments of the present invention, the refrigerator includes a box body 200 , and a compressor compartment 300 is disposed at the bottom of the box body 200 .

[0171] At this point, those skilled in the art should recognize that, although multiple exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications that conform to the principles of the present invention can still be directly determined or derived based on the content disclosed in the present invention without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should be understood and recognized as covering all these other variations or modifications.

Claims

1. A method for designing an acoustic metamaterial structure, characterized in that: include: S100, obtaining a noise spectrum of operating noise of a target device and an available space volume of an installation space of an acoustic metamaterial structure; S200, obtaining a target absorption spectrum of the acoustic metamaterial structure that can achieve a preset noise reduction effect for the noise spectrum under the condition that the volume of the acoustic metamaterial structure is not greater than the volume of the available space; S300, obtaining a design model of the acoustic material structure at least according to the available space volume and the target absorption spectrum.

2. The method according to claim 1, characterized in that Step S300 includes: S301, creating a simulation model of the acoustic metamaterial structure at least according to the available space volume; S302, obtaining a simulated absorption spectrum of the simulation model under the noise spectrum condition; S303, determining whether the difference between the simulated absorption spectrum of the simulation model and the target absorption spectrum of the acoustic metamaterial structure meets a preset condition, If so, the simulation model is used as the design model of the acoustic material structure.

3. The method according to claim 2, characterized in that Step S301 also includes: extracting sensitive parameters that affect the simulated absorption spectrum in the simulation model; and After determining whether the difference between the simulated absorption spectrum of the simulation model and the target absorption spectrum of the acoustic metamaterial structure meets a preset condition, the method further includes: If not, after adjusting the sensitive parameters of the simulation model, steps S302 and S303 are performed again.

4. The method according to claim 2, characterized in that: Step S200 includes: Extracting a target frequency value from the noise spectrum; Calculate the absorption frequency value based on the target frequency value, the available space volume and the preset noise reduction effect; The target absorption spectrum is obtained according to the noise spectrum and the absorption frequency value.

5. The method according to claim 4, characterized in that The extracting of the target frequency value in the noise spectrum includes: Extracting a preset multiple noise spectrum of the noise spectrum; At least a peak noise frequency value corresponding to the maximum sound pressure level amplitude in the preset multiple noise spectrum is extracted, and the peak noise frequency value is used as the target frequency value.

6. The method according to claim 4, characterized in that The extracting of the target frequency value in the noise spectrum includes: At least a given noise frequency value emitted by a preset noise source is extracted from the noise spectrum, and the given noise frequency value is used as the target frequency value.

7. The method according to claim 4, characterized in that The step of creating a simulation model of the acoustic metamaterial structure comprises: According to the 1 / 4 wavelength tube principle, at least one resonant cavity having a length corresponding to the target frequency value is generated in the simulation model; and / or According to the resonant cavity principle, at least one resonant cavity having an opening size corresponding to the target frequency value is generated in the simulation model.

8. The method according to claim 3, characterized in that The step of creating a simulation model of the acoustic metamaterial structure comprises: generating an airflow channel and at least two resonance cavities in the simulation model, wherein the inlet of the resonance cavity is located on the channel wall of the airflow channel; and The sensitive parameter is at least one of the following: The shape of the simulation model, the size of the simulation model, the material of the simulation model, the sealing of the simulation model, the position of the inlet of the resonant cavity on the channel wall of the airflow channel, the shape of the resonant cavity, the length of the resonant cavity, the position of the resonant cavity relative to the airflow channel, and the number of the resonant cavities.

9. The method according to claim 2, characterized in that: Step S302 includes: The COMSOL software is used to perform theoretical simulation of noise reduction of the simulation model to obtain an insertion loss spectrum under the noise spectrum condition, and the insertion loss spectrum is used as the simulated absorption spectrum.

10. The method according to claim 1, characterized in that After step S300, the method further includes: S400, manufacturing the acoustic metamaterial structure according to the design model; S500, installing the acoustic metamaterial structure in the acoustic metamaterial structure installation space of the target device, and detecting the operating noise of the target device to generate a noise reduction spectrum; S600: Compare the noise reduction spectrum with the noise spectrum.

11. An acoustic metamaterial noise reduction device, characterized in that: include: An acoustic metamaterial structure, wherein at least two resonant cavities are formed on the acoustic metamaterial structure, and a design model for manufacturing the acoustic metamaterial structure is obtained at least by the method described in any one of claims 1 to 10; A connection structure is configured to enable installation of the acoustic metamaterial structure within an installation space on a target device.

12. The acoustic metamaterial noise reduction device according to claim 11, characterized in that: A straight through airflow channel is also formed on the acoustic material structure, and the inlet of each resonance cavity is located on the channel wall of the airflow channel.

13. The acoustic metamaterial noise reduction device according to claim 11, characterized in that: At least part of at least one of the resonant cavities extends along a straight line, a broken line or a curved line.

14. The acoustic metamaterial noise reduction device according to claim 11, characterized in that: The thickness d of the acoustic material structure satisfies the following formula: Where λ is the wavelength of sound waves in air; A(λ) is the target spectrum.

15. The acoustic metamaterial noise reduction device according to claim 11, characterized in that: The thickness d of the acoustic material structure satisfies the following formula: Where λ is the wavelength of sound waves in air; A(λ) is the target spectrum; E(λ) is the noise spectrum; ΔSPL is the preset noise reduction effect.

16. A refrigerator, characterized in that: include: A compressor compartment, wherein a heat dissipation window is formed on at least one side compartment wall and / or a bottom plate of the compressor compartment; The acoustic metamaterial noise reduction device according to any one of claims 11 to 15, wherein the acoustic metamaterial noise reduction device is arranged on the heat dissipation window.

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