Acoustic number theory diffuser of composite Helmholtz resonator unit and design method

Abstract

The invention relates to the technical field of acoustic diffusion, in particular to an acoustic number theory diffuser of a composite Helmholtz resonator unit and a design method. The acoustic number theory diffuser of the composite Helmholtz resonator unit comprises at least one Helmholtz resonator unit and at least one bottom containing cavity, and the Helmholtz resonator unit is composed of at least two Helmholtz resonators and installed in the bottom containing cavity to form an acoustic diffusion module of a specific structure. Comprising a first cavity structure formed by Helmholtz resonator units, a second cavity structure formed by the Helmholtz resonator units and the wall surface of the accommodating cavity, and a third cavity structure formed by the Helmholtz resonator units and the opening of the accommodating cavity. According to the acoustic diffuser, a good acoustic diffusion effect can be generated in a wider frequency range, the problems that a traditional acoustic diffuser is high in frequency selectivity and high in structural size correlation are solved, and the acoustic diffuser is small in structural size, simple in design and suitable for being used in a small-size acoustic environment.

Description

Technical Field

[0001] This invention relates to the field of acoustic diffusion technology, and more particularly to acoustic number theory diffusers and design methods for composite Helmholtz resonator units. Background Technology

[0002] In the field of architectural acoustics design, acoustic diffusers are widely used to eliminate acoustic defects such as echoes, sound coloration, and sound focusing, playing a crucial role in improving sound field uniformity and spatial perception. Among common acoustic diffusers, the Schroeder diffuser has been extensively studied due to its simple design principle and predictable scattered sound field. However, due to the limitations of the Schroeder diffuser's structural design principle, it can only exhibit good sound diffusion effects within a limited frequency range. Therefore, how to overcome the limitations of quadratic remainder diffuser structural design and obtain better diffusion performance over a wider frequency range has become an urgent desire. Furthermore, in the acoustic design of small rooms (such as listening rooms, recording studios, or practice rooms), to ensure good uniformity and absence of acoustic defects in the indoor sound field, a large number of sound-absorbing and sound-diffusing structures are required, leading to a compression of usable space. Therefore, using small-volume, high-performance sound-diffusing structures in small rooms is of great significance for balancing the acoustic design of small rooms. Summary of the Invention

[0003] This invention overcomes the shortcomings of the prior art and provides an acoustic number theory diffuser for a composite Helmholtz resonator unit and its design method.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: This invention provides an acoustic number-theoretic diffuser for a composite Helmholtz resonator unit, the acoustic number-theoretic diffuser comprising a sound diffusion module, which includes a first type of sound diffusion module, a second type of sound diffusion module, and a third type of sound diffusion module: The sound diffusion module is rectangular in shape. Multiple sound diffusion modules are set according to the actual application scenario, with a minimum of three. Multiple sound diffusion modules are combined in parallel to form an acoustic number theory diffuser. The sound diffusion module is an open sound receiving device. The sound diffusion module includes a Helmholtz resonator unit and a bottom receiving cavity. The Helmholtz resonator unit is installed in the bottom receiving cavity, so that the whole forms a sound diffusion module. The Helmholtz resonator unit includes a Helmholtz resonator, and at least two Helmholtz resonators are provided. The neck width of the neck of the Helmholtz resonator is 2mm to 15mm and the neck depth is 5mm to 20mm. Multiple Helmholtz resonators are arranged adjacent to each other in a longitudinal manner. The bottom receiving cavity is a trap-shaped structure extending in one direction. The width of the trap-shaped structure is 20mm to 120mm and the depth is 40mm to 350mm. The bottom receiving cavity is composed of a receiving cavity bottom plate and a receiving cavity wall plate spliced ​​together. Receiving cavity wall plates of the same specification are fixed at both ends of the receiving cavity bottom plate. The receiving cavity wall plates are perpendicular to the receiving cavity bottom plate, and the receiving cavity wall plates at both ends are parallel to each other. The cavity bottom plate and cavity wall plate are both made of specific materials, including aluminum alloy, iron, wood and polymer materials. The thickness of the cavity bottom plate is 5mm to 35mm and the thickness of the cavity wall plate is 1mm to 15mm.

[0005] Furthermore, in a preferred embodiment of the present invention, the Helmholtz resonator unit is provided with a first resonant cavity structure, and the number of the first resonant cavity structures is consistent with the number of Helmholtz resonators constituting the Helmholtz resonator unit in different sound diffusion modules.

[0006] Furthermore, in a preferred embodiment of the present invention, a second resonant cavity structure is formed between the Helmholtz resonator unit and the cavity wall plate. The width of the second resonant cavity structure is 5mm to 20mm, and the depth is consistent with the height of the Helmholtz resonator unit provided in the corresponding sound diffusion module.

[0007] Furthermore, in a preferred embodiment of the present invention, a third resonant cavity structure is formed between the Helmholtz resonator unit and the opening of the bottom receiving cavity. The width of the third resonant cavity structure is consistent with the width of the bottom receiving cavity. The height of the third resonant cavity structure is determined by calculation using the number theory sequence method, which includes the quadratic remainder sequence and the primitive root sequence.

[0008] Furthermore, in a preferred embodiment of the present invention, the height of the Helmholtz resonator unit is the difference between the depth of the bottom accommodating cavity and the height of the third resonant cavity structure. When the height of the third resonant cavity structure is equal to the bottom accommodating depth, the Helmholtz resonator unit is not provided in the sound diffusion module, thus forming a fourth type of sound diffusion module.

[0009] Furthermore, in a preferred embodiment of the present invention, the second resonant cavity structures between each acoustic diffusion module in the acoustic number theory diffuser are arranged in parallel in a specific arrangement, the specific arrangement including a unidirectional arrangement and a symmetrical arrangement.

[0010] Furthermore, in a preferred embodiment of the present invention, after the sound diffusion modules are arranged in parallel in a specific manner, the surface trap-like structure between the first resonant cavity structure, the second resonant cavity structure, and the third resonant cavity structure and the bottom receiving cavity constitutes a local reactor for local resonant reaction and diffusion of sound.

[0011] The second aspect of this invention provides a design method for an acoustic number-theoretic diffuser of a composite Helmholtz resonator unit, applicable to the acoustic number-theoretic diffuser of any of the composite Helmholtz resonator units described in any one of the claims, specifically including the following steps: The target application scenario of the acoustic number theory diffuser is obtained, and the target frequency range, expected diffusion index and sound energy uniformity index of sound diffusion are extracted based on the target application scenario. The number of sequences in the nth acoustic diffusion module is calculated by introducing the primitive root sequence, and the obstacle constraint function is preset according to the recursive arrangement rule of the sequence number from large to small. Based on the ideal diffusion boundary anchored in the structural design specification system of the Helmholtz resonator unit according to the expected diffusion index and acoustic energy uniformity index, the range of geometric variable parameters is obtained. Based on the range of geometric variable parameters, a nonlinear center search path for the acoustic number theory diffuser that fits the target application scenario is established. The nonlinear center search path is penalized based on the obstacle constraint function to determine the frequency feasible region direction that approaches the ideal diffusion boundary, and the iteration step size with the gradient of the objective function is set according to the target frequency range. The cavity size ratio and arrangement of the acoustic diffusion module are automatically iteratively updated and calculated along the feasible frequency domain according to the iteration step size, and several candidate design parameter combinations of the acoustic number theory diffuser structure are output. By combining the proposed design parameters in each set of candidate design parameters to calculate the composite impedance of the first cavity structure and the second cavity structure and the acoustic impedance of the third cavity structure, the reflection coefficient of the acoustic impedance of the local reactor surface is obtained, and the optimal design parameter set of the acoustic number theory diffuser is obtained by analyzing the reflection coefficient. A three-dimensional model of an acoustic number theory diffuser and a sound simulation field of the target application scenario are constructed. The sound diffusion of the three-dimensional model of the acoustic number theory diffuser is simulated by the sound simulation field to generate a simulated sound field distribution heat map. Based on the sound diffusion requirements of the target application scenario, it is determined whether the local thermal transition color of the simulated sound field distribution heat map has shifted compared with the ideal color gamut reference, thereby verifying the design rationality of the acoustic number theory diffuser.

[0012] Furthermore, in a preferred embodiment of the present invention, the step of combining and calculating the composite impedance of the first cavity structure and the second cavity structure and the acoustic impedance of the third cavity structure using the proposed design parameters in each set of candidate design parameter combinations to obtain the reflection coefficient of the local reactor surface acoustic impedance, and analyzing the reflection coefficient to obtain the optimal design parameter set of the acoustic number theory diffuser, specifically includes the following steps: Extract the height and width design parameters of the first cavity structure corresponding to the nth acoustic diffusion module in each set of candidate design parameter combinations, and extract the width and depth design parameters of the second cavity structure and the depth design parameters of the third cavity structure. The volume ratio of the first cavity structure to the second cavity structure is calculated based on the height and width design parameters of the first cavity structure and the width design parameter of the second cavity structure. The impedance between the first cavity structure and the second cavity structure is calculated by combining the volume ratio with the depth design parameter of the second cavity structure to obtain the composite impedance. The maximum wavelength value of the target frequency range is obtained. Based on the maximum wavelength value and the depth design parameters of the third cavity structure, the acoustic impedance of the third cavity structure is calculated. The composite impedance and the acoustic impedance are added together to obtain the surface acoustic impedance of the local reactor of the acoustic number theory diffuser. Finally, the reflection coefficient of the surface of the local reactor is determined based on the surface acoustic impedance. If the reflection coefficient is not within the preset range of reflection coefficient values, the candidate design parameter combination is ignored; if it is within the preset range of reflection coefficient values, the candidate design parameter combination is retained, and only the candidate design parameter combination corresponding to the maximum reflection coefficient is extracted and marked as the optimal design parameter group of the acoustic number theory diffuser.

[0013] Furthermore, in a preferred embodiment of the present invention, the construction of a three-dimensional model of an acoustic number-theory diffuser and a sound simulation field of the target application scenario, the sound diffusion simulation of the three-dimensional model of the acoustic number-theory diffuser through the sound simulation field to generate a simulated sound field distribution heatmap, and the determination of whether the local thermal transition color of the simulated sound field distribution heatmap has shifted compared with the ideal color gamut reference based on the sound diffusion requirements of the target application scenario, thereby verifying the design rationality of the acoustic number-theory diffuser, specifically includes the following steps: By inputting the optimal design parameter set into the PROE model design software for modeling analysis, a three-dimensional model of an acoustic number theory diffuser suitable for the target application scenario is constructed. Based on big data networks, sound acquisition experience cases of target application scenarios are obtained. Several historical sound environment signals of the target application scenarios in continuous time sequence are extracted through sound acquisition experience cases. Boundary element algorithm is introduced to perform energy rendering on several historical sound environment signals to obtain the sound simulation field of the target application scenario. The three-dimensional model of the acoustic number theory diffuser is imported into the sound simulation field for simulation, and the sound field changes of the three-dimensional model of the acoustic number theory diffuser are recorded when the normal incidence is recorded during the simulation to obtain multiple sets of simulated sound field diffusion data. Based on multiple sets of simulated sound field diffusion data, a sound field distribution heat map of the acoustic number theory diffuser of the composite Helmholtz resonator unit was plotted under normal incidence. This heat map was labeled as a simulated sound field distribution heat map and divided into several two-dimensional diffusion orientation blocks. Based on the acoustic diffusion requirements, the ideal sound field distribution benchmark of the acoustic number theory diffuser is extracted and specified for different two-dimensional diffusion orientation blocks when the diffuser is normally incident in the target application scenario. Based on the ideal sound field distribution benchmark, the transition color gamut specification of the ideal sound field thermodynamic gradient corresponding to different two-dimensional diffusion orientation blocks is established. If the local thermal transition color of the two-dimensional diffusion orientation block in the simulated sound field distribution heat map does not exist in the transition color gamut specification of the corresponding ideal sound field thermal gradient, then mark the two-dimensional diffusion orientation block as an offset diffusion block and obtain the number of offset diffusion blocks in the simulated sound field distribution heat map. If the quantity value is less than the preset quantity threshold, the acoustic number theory diffuser is marked as qualified; otherwise, it is marked as unqualified.

[0014] The beneficial technical effects of this invention are as follows: This invention utilizes a composite Helmholtz resonator unit method to broaden the effective diffusion frequency of traditional number-theoretical acoustic diffusers. This significantly reduces the structural design frequency of traditional number-theoretical acoustic diffusers, overcoming the limitation that they only produce sound diffusion within a limited frequency range. Simultaneously, it improves the diffusion performance of the diffuser within the effective diffusion frequency range. Secondly, this invention reduces the design volume of traditional number-theoretical acoustic diffusers. Compared to traditional number-theoretical acoustic diffusers, the volume is reduced by 20% to 45% while maintaining the same structural design frequency. This improves the space utilization in the sound quality design process within limited space, while also reducing installation requirements and increasing installation efficiency. Furthermore, the acoustic number-theoretical diffuser of this invention, based on the composite Helmholtz resonator unit, has a clear structural design method and sound diffusion theory, allowing for customized designs according to different application scenarios, thus overcoming the limitations of traditional number-theoretical acoustic diffusers. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained from these drawings without creative effort.

[0016] Figure 1This is a schematic diagram of the three-dimensional structure of the acoustic number theory diffuser; Figure 2 A schematic cross-sectional view of the second resonant cavity structures arranged in the same direction between the acoustic diffusion modules; Figure 3 A schematic cross-sectional view of the symmetrical arrangement of the second resonant cavity structures between the acoustic diffusion modules; Figure 4 This is a side view of the first type of acoustic diffusion module. Figure 5 This is a side view of the second type of acoustic diffusion module. Figure 6 This is a schematic diagram of the side structure of the third type of sound diffusion module; Figure 7 A schematic diagram of the normalized diffusion coefficient for a symmetrically arranged and assembled acoustic number theory diffuser; Figure 8 This is a schematic diagram of the polar coordinate response of the sound pressure level of this acoustic number theory diffuser at a frequency of 1250 Hz; Figure 9 This is a schematic diagram of the sound field distribution of this acoustic number theory diffuser at a frequency of 1000Hz.

[0017] The annotations in the attached figures are explained as follows: 101. Sound diffusion module; 102. Type I sound diffusion module; 103. Type II sound diffusion module; 104. Type III sound diffusion module; 105. Type IV sound diffusion module; 106. Helmholtz resonator; 107. Bottom cavity; 108. Cavity bottom plate; 109. Cavity wall plate; 201. Helmholtz resonator neck; 202. First cavity structure; 203. Second cavity structure; 204. Third cavity structure. Detailed Implementation

[0018] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner. Therefore, they only show the components related to the present invention. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0019] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the scope of protection of this application. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0020] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art will understand the specific meaning of the above terms in this application based on the specific circumstances.

[0021] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0022] like Figures 1-6 As shown, the first aspect of the present invention provides an acoustic number theory diffuser for a composite Helmholtz resonator unit, the acoustic number theory diffuser including an acoustic diffusion module 101, the acoustic diffusion module 101 including a first type of acoustic diffusion module 102, a second type of acoustic diffusion module 103 and a third type of acoustic diffusion module 104.

[0023] The sound diffusion module 101 is rectangular in shape. Multiple sound diffusion modules 101 are provided according to the actual application scenario, with a minimum of three. Multiple sound diffusion modules 101 are combined in parallel to form an acoustic number theory diffuser. The sound diffusion module 101 is an open sound receiving device. The sound diffusion module 101 includes a Helmholtz resonator unit and a bottom receiving cavity 107. The Helmholtz resonator unit is installed in the bottom receiving cavity 107, so that the whole forms a sound diffusion module 101.

[0024] It should be noted that, in different application scenarios, the acoustic number theory diffuser structure of this invention, through the composite design of introducing a Helmholtz resonator unit and a bottom receiving cavity 107 into the long rectangular sound diffusion module 101, enables each sound diffusion module 101 to not only passively scatter sound waves, but also, with the internal Helmholtz resonator unit and the bottom receiving cavity 107 coupled together, to form multiple resonant channels of different frequencies, achieving effective diffusion and absorption compensation of mid-to-low frequency sound energy, thereby achieving sound energy diffusion and equalization over a wide frequency range. Simultaneously, the number theory arrangement of multiple modules in parallel effectively overcomes the limitation of traditional quadratic remainder diffusers, which only achieve good diffusion within a limited frequency band. Furthermore, the open-type sound receiving design enhances multi-path reflection and phase perturbation after sound wave incidence, improving the diffusion uniformity of the spatial sound field. Compared with traditional acoustic diffusers, this diffuser structure has a more significant diffusion effect in terms of improving diffusion bandwidth, enhancing the uniformity of spatial sound energy distribution, and suppressing sound focusing and sound coloration. It not only broadens the effective frequency range of sound diffusion, but also significantly improves the uniformity and diffusion index of the spatial sound field. This overcomes the bottleneck of traditional quadratic remainder acoustic diffusers in terms of broadband diffusion capability and sound field consistency, and provides an efficient, adjustable and compact sound diffusion structure improvement and optimization for high-quality sound field optimization in architectural acoustic environments.

[0025] It should be noted that, compared with traditional number theory acoustic diffusers, the present invention has a significantly reduced structural volume and a relatively simple overall design, making it easy to customize and install in different application scenarios to meet sound diffusion requirements. It can reduce the volume by 20% to 45% while maintaining the same structural design frequency, and can minimize the space occupied while maintaining ideal sound quality, thus improving the space utilization rate of narrow spaces in the sound quality design process.

[0026] The Helmholtz resonator unit includes a Helmholtz resonator 106, and at least two Helmholtz resonators 106 are provided. The neck width of the neck 201 of the Helmholtz resonator is 2mm to 15mm and the neck depth is 5mm to 20mm. Multiple Helmholtz resonators 106 are arranged adjacent to each other in a longitudinal manner.

[0027] It should be noted that the multiple Helmholtz resonator necks 201 can form different resonant frequencies within the parameter range of neck width 2mm to 15mm and neck depth 5mm to 20mm, enabling the sound diffusion module 101 to generate multi-band resonance in the low-to-mid-high frequency range, thereby achieving more stable and superior broadband sound energy diffusion and multi-frequency scattering enhancement. The longitudinally arranged Helmholtz resonator structure design not only generates coupling effects and interference enhancement between the resonant units, increasing the complexity of the sound wave propagation path within the diffuser, but also increases the number of scattering interfaces per unit area, significantly improving the uniformity of sound energy distribution. The Helmholtz resonator unit of this invention effectively achieves efficient diffusion of multi-band sound waves, suppression of sound focusing and echoes, and enhancement of sound field spatiality and diffusion index, thereby obtaining excellent sound diffusion performance over a wider frequency range.

[0028] The bottom receiving cavity 107 is a trap-shaped structure extending in one direction. The width of the trap-shaped structure is 20mm to 120mm and the depth is 40mm to 350mm. The bottom receiving cavity 107 is composed of a receiving cavity bottom plate 108 and a receiving cavity wall plate 109 spliced ​​together. Receiving cavity wall plates 109 of the same specification are fixed at both ends of the receiving cavity bottom plate 108. The receiving cavity wall plates 109 and the receiving cavity bottom plate 108 are perpendicular to each other, and the receiving cavity wall plates 109 at both ends are distributed in parallel.

[0029] The cavity bottom plate 108 and the cavity wall plate 109 are both made of specific materials, including aluminum alloy, iron, wood and polymer materials. The thickness of the cavity bottom plate 108 is 5mm to 35mm, and the thickness of the cavity wall plate 109 is 1mm to 15mm.

[0030] It should be noted that this invention, by reasonably controlling the width parameter range of the bottom receiving cavity 107 to 20mm-120mm and the depth parameter range to 40mm-350mm, precisely controls the multi-level spatial modulation and phase delay of sound wave energy, effectively solving the inherent problems of narrow diffusion bandwidth and uneven sound energy distribution of traditional Schroeder diffusers. Secondly, the parallel distribution of the receiving cavity wall plates 109 at both ends forms a regular reflection interface, causing the sound waves to produce multiple reflections and interference superposition effects within the cavity, enhancing the scattering complexity and spatial distribution uniformity of the sound waves. Thirdly, by designing specific ranges of 5mm-35mm thickness for the receiving cavity bottom plate 108 and 1mm-15mm thickness for the receiving cavity wall plates 109, and selecting different materials such as aluminum alloy, iron, wood, or polymer materials, the stiffness and vibration absorption characteristics of the structure can be adjusted according to the target frequency band of the application scenario, thereby achieving directional diffusion and resonance control of sound waves of different frequencies.

[0031] In summary, the bottom cavity 109 structure of the present invention not only significantly broadens the effective operating frequency band of the sound diffuser, but also further improves the diffusion index and spatial uniformity of the sound field, effectively suppressing sound focusing and echo phenomena. It is an acoustic diffusion structure that integrates structural stability, strong adjustability and excellent broadband response.

[0032] The Helmholtz resonator unit has a first resonant cavity structure 202, and the number of the first resonant cavity structures 202 is the same as the number of Helmholtz resonators 106 constituting the Helmholtz resonator units in different sound diffusion modules 101.

[0033] A second resonant cavity structure 203 is formed between the Helmholtz resonator unit and the cavity wall plate 109. The width of the second resonant cavity structure 203 is 5mm to 20mm, and the depth is consistent with the height of the Helmholtz resonator unit set in the corresponding sound diffusion module 101.

[0034] A third resonant cavity structure 204 is formed between the Helmholtz resonator unit and the opening of the bottom receiving cavity 107. The width of the third resonant cavity structure 204 is consistent with the width of the bottom receiving cavity 107. The height of the third resonant cavity structure 204 is determined by calculation using the number theory sequence method, which includes the quadratic remainder sequence and the primitive root sequence.

[0035] It should be noted that the first resonant cavity structure 202 corresponds one-to-one with each Helmholtz resonator unit, and is used to form independent resonant channels in different frequency bands, enhancing the absorption and scattering ability of sound waves in the mid-to-low frequency range. The second resonant cavity structure 203 is set between the Helmholtz resonator unit and the cavity wall plate 109. By reasonably controlling the width range of 5mm to 20mm and the depth consistent with the unit height, the sound waves generate multi-level coupling and phase interference between the diffuser structures, thereby improving the uniformity of sound diffusion. The third resonant cavity structure 204 is located at the opening between the Helmholtz resonator unit and the bottom cavity 107. Its height is determined by the number theory sequence method of quadratic remainder sequence and primitive root sequence, which effectively overcomes the resonance limitations of traditional Schroeder diffusers with narrow frequency band and low diffusion efficiency, so that the sound wave scattering path is non-linearly distributed under mathematical laws, thus widening the diffusion frequency band.

[0036] The following is an example of this embodiment: A sequence is obtained by calculating the quadratic remainder sequence using odd prime number N=7. The result of the sequence calculation is as follows: [0, 1, 4, 2, 2, 4, 1]. The acoustic number-theoretic diffuser of the Helmholtz resonator unit designed according to this sequence includes 7 acoustic diffusion modules 101. The bottom cavity 107 of the acoustic diffusion module 101 of this 7th-order acoustic number-theoretic diffuser is made of spliced ​​wooden boards with a thickness of 10mm, forming a cavity depth of 80mm after splicing. The first cavity structure 202 inside the Helmholtz resonator unit has a height of 16.875mm and a width of 40mm. The Helmholtz resonator 106 has a width of 5mm and a depth of 5mm.

[0037] After connecting the sound diffusion modules 101 in parallel as described above, the sound diffusion modules 101 in the acoustic number theory diffuser of the resulting 7th-order composite Helmholtz resonator unit have a continuous structure along the y-axis, and the material of the diffuser unit is oak. For example... Figure 7 The diagram shown is a normalized diffusion coefficient diagram of a diffuser structure assembled in a symmetrical arrangement, as follows. Figure 8 The figure shows the polar coordinate response of the diffuser structure at a frequency of 1250 Hz. Figure 9 The sound field distribution diagram of the diffuser structure shown is at a frequency of 1000Hz.

[0038] In summary, the layered cavity coupling resonance and number theory sequence design of this invention enable the acoustic number theory diffuser to achieve the gain effect of multi-band resonance superposition, sound field phase randomization and energy uniform distribution, significantly improving the diffusion performance and spatial sound field uniformity over a wide frequency range, and overcoming the shortcomings of traditional diffusers such as limited frequency band and insufficient sound diffusion consistency.

[0039] The height of the Helmholtz resonator unit is the difference between the depth of the bottom accommodating cavity and the height of the third resonant cavity structure. When the height of the third resonant cavity structure is equal to the bottom accommodating depth, the Helmholtz resonator unit is not set in the sound diffusion module, forming a fourth type of sound diffusion module.

[0040] It should be noted that the fourth type of sound diffusion module 105 is mainly used for pure reflected sound frequency and phase perturbation. It can summarize the acoustic response types and frequency band distribution of the diffuser to meet the sound diffusion requirements of specific frequencies in actual application scenarios. In this way, it can achieve dynamic optimization of multi-band resonance, sound field response and modular adjustment, broaden the effective diffusion frequency range, and significantly enhance the uniformity of spatial sound energy distribution and sound field diffusion index.

[0041] The second resonant cavity structures between each acoustic diffusion module in the acoustic number theory diffuser are arranged in parallel in a specific arrangement, which includes a unidirectional arrangement and a symmetrical arrangement.

[0042] It should be noted that the co-directional arrangement of the second resonant cavity structure 203 enables the sound wave to form a coherent propagation path between modules, smoothly transitioning the frequency response; while the symmetrical arrangement of the second resonant cavity structure 203 enhances the multipath interference and phase perturbation of the sound wave through spatial reflection symmetry, improving the scattering complexity of the sound wave within the diffuser. The acoustic number-theory diffuser of this invention employs co-directional or symmetrical cavity structure arrangements according to different application scenarios, thereby enabling the resonance effects between each sound diffusion module 101 to be tightly coupled, forming multi-band resonance superposition and balanced sound energy distribution, thus significantly broadening the effective operating frequency range of the diffuser in application scenarios, and exhibiting superior diffusion performance compared to traditional number-theory acoustic diffusers.

[0043] After the sound diffusion modules are arranged in parallel in a specific manner, the surface trap-like structure between the first resonant cavity structure, the second resonant cavity structure, the third resonant cavity structure and the bottom receiving cavity constitutes a local reactor for the local resonance reaction and diffusion of sound.

[0044] It should be noted that the design of this local reactor enables sound waves propagating in an indoor or enclosed space to generate multi-band resonance within a single sound diffusion module 101 after normal incidence. This creates coupling interference and multipath scattering between modules, improving the uniformity and spatial distribution complexity of sound wave diffusion. The local reactor configuration of this invention allows the acoustic number-theoretic diffuser to complete efficient sound energy conversion and diffusion over a wider frequency range, effectively suppressing echoes, sound coloration, and sound focusing phenomena, and enhancing the uniformity and spatial sense of the overall sound field.

[0045] The second aspect of this invention provides a design method for an acoustic number-theoretic diffuser of a composite Helmholtz resonator unit, applicable to the acoustic number-theoretic diffuser of any of the composite Helmholtz resonator units described in any one of the claims, specifically including the following steps: The target application scenario of the acoustic number theory diffuser is obtained, and the target frequency range, expected diffusion index and sound energy uniformity index of sound diffusion are extracted based on the target application scenario. The number of sequences in the nth acoustic diffusion module is calculated by introducing the primitive root sequence, and the obstacle constraint function is preset according to the recursive arrangement rule of the sequence number from large to small. Based on the ideal diffusion boundary anchored in the structural design specification system of the Helmholtz resonator unit according to the expected diffusion index and acoustic energy uniformity index, the range of geometric variable parameters is obtained. Based on the range of geometric variable parameters, a nonlinear center search path for the acoustic number theory diffuser that fits the target application scenario is established. The nonlinear center search path is penalized based on the obstacle constraint function to determine the frequency feasible region direction that approaches the ideal diffusion boundary, and the iteration step size with the gradient of the objective function is set according to the target frequency range. The cavity size ratio and arrangement of the acoustic diffusion module are automatically iteratively updated and calculated along the feasible frequency domain according to the iteration step size, and several candidate design parameter combinations of the acoustic number theory diffuser structure are output. By combining the proposed design parameters in each set of candidate design parameters to calculate the composite impedance of the first cavity structure and the second cavity structure and the acoustic impedance of the third cavity structure, the reflection coefficient of the acoustic impedance of the local reactor surface is obtained, and the optimal design parameter set of the acoustic number theory diffuser is obtained by analyzing the reflection coefficient. A three-dimensional model of an acoustic number theory diffuser and a sound simulation field of the target application scenario are constructed. The sound diffusion of the three-dimensional model of the acoustic number theory diffuser is simulated by the sound simulation field to generate a simulated sound field distribution heat map. Based on the sound diffusion requirements of the target application scenario, it is determined whether the local thermal transition color of the simulated sound field distribution heat map has shifted compared with the ideal color gamut reference, thereby verifying the design rationality of the acoustic number theory diffuser.

[0046] It should be noted that while the acoustic number-theoretic diffuser of the composite Helmholtz resonator unit can be customized according to different application scenarios, its design still relies on manual calculation to determine precise structural parameters. This may introduce design errors due to human intervention, potentially leading to the acoustic number-theoretic diffuser product failing to achieve the expected sound diffusion across a wider frequency range in the specified application scenario. This reduces the overall performance of the acoustic number-theoretic diffuser and increases the rework rate in its manufacturing. To address this, this method first utilizes primitive root sequences to generate a spatial distribution sequence of the acoustic diffusion modules, thus forming a non-periodic but controllable spatial structure arrangement. This imbues the arrangement with mathematical randomness, enabling the acoustic diffusion modules to achieve a broadband diffusion effect in the frequency domain. This ensures that sound waves produce dispersed reflections across multiple frequency ranges, thereby achieving a balance between diffusion characteristics and uniformity, while avoiding interference peaks and valleys caused by periodic structures. Furthermore, this method pre-defines a barrier constraint function based on a descending order of sequence numbers. This barrier constraint function prevents parameter variables from approaching zero through a logarithmic penalty term, ensuring that the search path for the acoustic diffusion module parameter design always lies within the feasible domain of the specified frequency, approximating the optimal parameter values ​​at the diffusion boundary. Subsequently, the theoretical acoustic performance of the desired diffusion index and acoustic energy uniformity index is mapped to the parameter space at the structural level of the Helmholtz resonator unit, forming a nonlinear center search path leading to the optimal reference between the acoustic performance target and the structural geometric design. This nonlinear center search path provides the search range and path basis for design parameters of different structural indices (cavity width, depth, or volume) while ensuring structural physical feasibility and meeting the acoustic diffusion requirements of the target application scenario. This avoids parameter design falling into local optima, enabling the final acoustic diffusion module to achieve a global dynamic balance in terms of structure and acoustic performance.

[0047] It should be noted that penalizing the nonlinear center search path based on the obstacle constraint function applies obstacle suppression of each structural design parameter value along the nonlinear center search path using a sequence of primitive roots. Only parameter candidate directions that simultaneously satisfy both structural constraints and acoustic performance requirements are retained, thus gradually approaching the ideal diffusion boundary. This ensures that the final design parameters meet the diffusion requirements within the specified frequency range of the target application scenario. The iteration step size is a key parameter controlling the update amplitude according to the target frequency range, preventing parameter values ​​from jumping out of the target frequency range boundary and ensuring that the continuously updated parameter points remain within the frequency feasible region. Finally, by automatically iterating the cavity size ratio and arrangement of the acoustic diffusion modules along the feasible frequency domain according to the iteration step size, a series of acoustic diffusion module design parameter combinations that satisfy the broad frequency diffusion performance of the target application scenario can be obtained. An example is as follows: The acoustic diffusion modules of the acoustic number-theoretic diffuser of the 7th-order (primitive root sequence) composite Helmholtz resonator unit include four types, three of which contain Helmholtz resonator units. The first type of acoustic diffusion module consists of a unit composed of four Helmholtz resonators, where the second cavity structure has a depth of 80mm and a width of 5mm, and the third... The first type of acoustic diffusion module has a cavity depth of 0 mm. The second type consists of a unit composed of three Helmholtz resonators, with the second cavity having a depth of 60.6 mm and a width of 5 mm, and the third cavity having a depth of 19.375 mm. The third type consists of a unit composed of two Helmholtz resonators, with the second cavity having a depth of 41.25 mm and a width of 5 mm, and the third cavity having a depth of 38.75 mm. The fourth type, which does not contain a Helmholtz resonator unit, has a second cavity with a depth of 0 mm and a width of 0 mm, and a third cavity with a depth of 80 mm. All acoustic diffusion modules are arranged in the same direction.

[0048] The formula for calculating the primitive root sequence is as follows: ;

[0049] In the formula, Let n be the sequence number of the nth acoustic diffusion module. yes" The abbreviation for "" indicates the non-negative remainder. It is an odd prime number. yes The original root, and has within each diffuser cycle Sink; Furthermore, the formula for calculating the height of the third cavity structure is as follows: ;

[0050] In the formula, The height of the third cavity structure in the nth sound diffusion module. Let n be the sequence number of the nth acoustic diffusion module. The wavelength corresponding to the design frequency of the structure. It is an odd prime number; In summary, this method enables precise parameter decision-making design for the acoustic number-theoretic diffuser of a composite Helmholtz resonator unit in a specified application scenario, replacing the cumbersome steps of traditional manual design, reducing intervention bias, ensuring the design accuracy and reliability of the acoustic number-theoretic diffuser of the composite Helmholtz resonator unit, and improving the diffusion performance of the acoustic number-theoretic diffuser in the target application scenario.

[0051] Furthermore, in a preferred embodiment of the present invention, the step of combining and calculating the composite impedance of the first cavity structure and the second cavity structure and the acoustic impedance of the third cavity structure using the proposed design parameters in each set of candidate design parameter combinations to obtain the reflection coefficient of the acoustic impedance of the local reactor surface, and analyzing the reflection coefficient to obtain the optimal design parameter set of the acoustic number theory diffuser, specifically includes the following steps: Extract the height and width design parameters of the first cavity structure corresponding to the nth acoustic diffusion module in each set of candidate design parameter combinations, and extract the width and depth design parameters of the second cavity structure and the depth design parameters of the third cavity structure. The volume ratio of the first cavity structure to the second cavity structure is calculated based on the height and width design parameters of the first cavity structure and the width design parameter of the second cavity structure. The impedance between the first cavity structure and the second cavity structure is calculated by combining the volume ratio with the depth design parameter of the second cavity structure to obtain the composite impedance. The maximum wavelength value of the target frequency range is obtained. Based on the maximum wavelength value and the depth design parameters of the third cavity structure, the acoustic impedance of the third cavity structure is calculated. The composite impedance and the acoustic impedance are added together to obtain the surface acoustic impedance of the local reactor of the acoustic number theory diffuser. Finally, the reflection coefficient of the surface of the local reactor is determined based on the surface acoustic impedance. If the reflection coefficient is not within the preset range of reflection coefficient values, the candidate design parameter combination is ignored; if it is within the preset range of reflection coefficient values, the candidate design parameter combination is retained, and only the candidate design parameter combination corresponding to the maximum reflection coefficient is extracted and marked as the optimal design parameter group of the acoustic number theory diffuser.

[0052] It should be noted that the volume ratio of the first cavity structure to the second cavity structure is calculated using the following formula: ;

[0053] In the formula, The height of the first cavity structure. The width of the first cavity structure, The width of the second cavity structure.

[0054] The formula for calculating the combined impedance of the first cavity structure and the second cavity structure is as follows: ;

[0055] In the formula, The imaginary unit, Angular frequency, air density, For wave number, For the diffuser The depth of the second cavity in the acoustic diffusion module It is the ratio of the volume of the first cavity structure to the volume of the second cavity structure.

[0056] The formula for calculating the acoustic impedance of the third cavity structure is as follows: ;

[0057] In the formula, The imaginary unit, air density, The speed of sound in air. The depth of the third cavity structure in the nth acoustic diffusion module. λ is the wavelength.

[0058] The formula for calculating the surface acoustic impedance of a local reactor is shown below: ;

[0059] In the formula, The combined impedance of the first cavity structure and the second cavity structure. The impedance of the third cavity structure.

[0060] The formula for calculating the reflection coefficient of a local reactor surface is as follows: ;

[0061] In the formula, Let n be the surface reflectance coefficient of the nth diffusion module. For the local reactor surface impedance, air density, The speed of sound in air.

[0062] It should be noted that this method can calculate the surface acoustic impedance of the local reactor of the designed acoustic number-theoretic diffuser according to the proposed parameter values ​​in the candidate design parameter combination, thereby further determining its reflection coefficient capability for a specific frequency range. By analyzing the quality of the reflection coefficient, the best-performing and most reasonable diffuser design parameter set is selected, ensuring that the designed acoustic number-theoretic diffuser product can achieve better sound diffusion effects in the specified frequency range of the target application scenario. Simultaneously, it provides a test input set for subsequent simulation verification.

[0063] Furthermore, in a preferred embodiment of the present invention, the construction of a three-dimensional model of an acoustic number-theory diffuser and a sound simulation field of the target application scenario, the sound diffusion simulation of the three-dimensional model of the acoustic number-theory diffuser using the sound simulation field to generate a simulated sound field distribution heatmap, and the determination of whether the local thermal transition color of the simulated sound field distribution heatmap has shifted compared to the ideal color gamut reference based on the sound diffusion requirements of the target application scenario, thereby verifying the design rationality of the acoustic number-theory diffuser, specifically includes the following steps: By inputting the optimal design parameter set into the PROE model design software for modeling analysis, a three-dimensional model of an acoustic number theory diffuser suitable for the target application scenario is constructed. Based on big data networks, sound acquisition experience cases of target application scenarios are obtained. Several historical sound environment signals of the target application scenarios in continuous time sequence are extracted through sound acquisition experience cases. Boundary element algorithm is introduced to perform energy rendering on several historical sound environment signals to obtain the sound simulation field of the target application scenario. The three-dimensional model of the acoustic number theory diffuser is imported into the sound simulation field for simulation, and the sound field changes of the three-dimensional model of the acoustic number theory diffuser are recorded when the normal incidence is recorded during the simulation to obtain multiple sets of simulated sound field diffusion data. Based on multiple sets of simulated sound field diffusion data, a sound field distribution heat map of the acoustic number theory diffuser of the composite Helmholtz resonator unit was plotted under normal incidence. This heat map was labeled as a simulated sound field distribution heat map and divided into several two-dimensional diffusion orientation blocks. Based on the acoustic diffusion requirements, the ideal sound field distribution benchmark of the acoustic number theory diffuser is extracted and specified for different two-dimensional diffusion orientation blocks when the diffuser is normally incident in the target application scenario. Based on the ideal sound field distribution benchmark, the transition color gamut specification of the ideal sound field thermodynamic gradient corresponding to different two-dimensional diffusion orientation blocks is established. If the local thermal transition color of the two-dimensional diffusion orientation block in the simulated sound field distribution heat map does not exist in the transition color gamut specification of the corresponding ideal sound field thermal gradient, then mark the two-dimensional diffusion orientation block as an offset diffusion block and obtain the number of offset diffusion blocks in the simulated sound field distribution heat map. If the quantity value is less than the preset quantity threshold, the acoustic number theory diffuser is marked as qualified; otherwise, it is marked as unqualified.

[0064] It should be noted that the transition color gamut specification is an ideal example of a gradient jump in the thermal color of the ideal sound field diffusion distribution at adjacent time nodes. For instance, if the ideal sound field distribution of a two-dimensional diffusion directional block is 70dB at one time node and 105dB at the next time node, then the thermal chromaticity gradually transitions from red to orange and then further to yellow. If the local thermal transition color of the two-dimensional diffusion directional block in the simulated sound field distribution heatmap does not exist in the transition color gamut specification of the corresponding ideal sound field thermal gradient, it indicates that the designed acoustic number theory diffuser product has caused a local frequency diffusion shift in the sound field distribution within the target application scenario area corresponding to the two-dimensional diffusion directional block, suggesting that the acoustic number theory diffuser product may have a design flaw of varying degrees. Therefore, this method further determines whether the number of offset diffusion blocks exceeds a specified threshold. If the number is less than the preset threshold, it indicates that the acoustic mathematical diffuser product of this design causes relatively few local diffusion deviations in the target application area, suggesting a possible accidental phenomenon. This indicates that the product's parameter design is relatively qualified and can be used for acoustic diffusion within the specified frequency range of the target application. Conversely, if the number exceeds the threshold, it indicates that the product design is unqualified and does not meet the acoustic diffusion expectations of the target application. This method enables simulation testing and diffusion verification of the optimally designed acoustic mathematical diffuser, thereby ensuring the accuracy of the acoustic mathematical diffuser design verification and the reliability of product performance for composite Helmholtz resonator units. It also reduces the distortion rate and diffusion deviation in the actual application of acoustic mathematical diffusers, improving the pass rate and overall quality of customized product designs.

[0065] The above description, based on preferred embodiments of the present invention, is quite specific and detailed, but it should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. An acoustic number-theoretic diffuser for a composite Helmholtz resonator unit, the acoustic number-theoretic diffuser comprising a sound diffusion module, the sound diffusion module comprising a first type of sound diffusion module, a second type of sound diffusion module, and a third type of sound diffusion module, characterized in that: The sound diffusion module is rectangular in shape. Multiple sound diffusion modules are set according to the actual application scenario, with a minimum of three. Multiple sound diffusion modules are combined in parallel to form an acoustic number theory diffuser. The sound diffusion module is an open sound receiving device. The sound diffusion module includes a Helmholtz resonator unit and a bottom receiving cavity. The Helmholtz resonator unit is installed in the bottom receiving cavity, so that the whole forms a sound diffusion module. The Helmholtz resonator unit includes a Helmholtz resonator, and at least two Helmholtz resonators are provided. The neck width of the neck of the Helmholtz resonator is 2mm to 15mm and the neck depth is 5mm to 20mm. Multiple Helmholtz resonators are arranged adjacent to each other in a longitudinal manner. The bottom receiving cavity is a trap-shaped structure extending in one direction. The width of the trap-shaped structure is 20mm to 120mm and the depth is 40mm to 350mm. The bottom receiving cavity is composed of a receiving cavity bottom plate and a receiving cavity wall plate spliced ​​together. Receiving cavity wall plates of the same specification are fixed at both ends of the receiving cavity bottom plate. The receiving cavity wall plates are perpendicular to the receiving cavity bottom plate, and the receiving cavity wall plates at both ends are parallel to each other. The cavity bottom plate and cavity wall plate are both made of specific materials, including aluminum alloy, iron, wood and polymer materials. The thickness of the cavity bottom plate is 5mm to 35mm and the thickness of the cavity wall plate is 1mm to 15mm.

2. The acoustic number-theoretic diffuser of the composite Helmholtz resonator unit according to claim 1, characterized in that, The Helmholtz resonator unit has a first resonant cavity structure, and the number of the first resonant cavity structures is the same as the number of Helmholtz resonators constituting the Helmholtz resonator unit in different sound diffusion modules.

3. The acoustic number-theoretic diffuser of the composite Helmholtz resonator unit according to claim 2, characterized in that, A second resonant cavity structure is formed between the Helmholtz resonator unit and the cavity wall plate. The width of the second resonant cavity structure is 5mm to 20mm, and the depth is consistent with the height of the Helmholtz resonator unit set in the corresponding sound diffusion module.

4. The acoustic number-theoretic diffuser of the composite Helmholtz resonator unit according to claim 3, characterized in that, A third resonant cavity structure is formed between the Helmholtz resonator unit and the opening of the bottom receiving cavity. The width of the third resonant cavity structure is consistent with the width of the bottom receiving cavity. The height of the third resonant cavity structure is determined by calculation using the number theory sequence method, which includes the quadratic remainder sequence and the primitive root sequence.

5. The acoustic number-theoretic diffuser of the composite Helmholtz resonator unit according to claim 1, characterized in that, The height of the Helmholtz resonator unit is the difference between the depth of the bottom accommodating cavity and the height of the third resonant cavity structure. When the height of the third resonant cavity structure is equal to the bottom accommodating depth, the Helmholtz resonator unit is not set in the sound diffusion module, forming a fourth type of sound diffusion module.

6. The acoustic number-theoretic diffuser of the composite Helmholtz resonator unit according to claim 1, characterized in that, The second resonant cavity structures between each acoustic diffusion module in the acoustic number theory diffuser are arranged in parallel in a specific arrangement, which includes a unidirectional arrangement and a symmetrical arrangement.

7. The acoustic number-theoretic diffuser of the composite Helmholtz resonator unit according to claim 1, characterized in that, After the sound diffusion modules are arranged in parallel in a specific manner, the surface trap-like structure between the first resonant cavity structure, the second resonant cavity structure, the third resonant cavity structure and the bottom receiving cavity constitutes a local reactor for the local resonance reaction and diffusion of sound.

8. A method for designing an acoustic number-theoretic diffuser for a composite Helmholtz resonator unit, applied to the acoustic number-theoretic diffuser of the composite Helmholtz resonator unit as described in any one of claims 1-7, characterized in that, Specifically, the following steps are included: The target application scenario of the acoustic number theory diffuser is obtained, and the target frequency range, expected diffusion index and sound energy uniformity index of sound diffusion are extracted based on the target application scenario. The number of sequences in the nth acoustic diffusion module is calculated by introducing the primitive root sequence, and the obstacle constraint function is preset according to the recursive arrangement rule of the sequence number from large to small. Based on the ideal diffusion boundary anchored in the structural design specification system of the Helmholtz resonator unit according to the expected diffusion index and acoustic energy uniformity index, the range of geometric variable parameters is obtained. Based on the range of geometric variable parameters, a nonlinear center search path for the acoustic number theory diffuser that fits the target application scenario is established. The nonlinear center search path is penalized based on the obstacle constraint function to determine the frequency feasible region direction that approaches the ideal diffusion boundary, and the iteration step size with the gradient of the objective function is set according to the target frequency range. The cavity size ratio and arrangement of the acoustic diffusion module are automatically iteratively updated and calculated along the feasible frequency domain according to the iteration step size, and several candidate design parameter combinations of the acoustic number theory diffuser structure are output. By combining the proposed design parameters in each set of candidate design parameters to calculate the composite impedance of the first cavity structure and the second cavity structure and the acoustic impedance of the third cavity structure, the reflection coefficient of the acoustic impedance of the local reactor surface is obtained, and the optimal design parameter set of the acoustic number theory diffuser is obtained by analyzing the reflection coefficient. A three-dimensional model of an acoustic number theory diffuser and a sound simulation field of the target application scenario are constructed. The sound diffusion of the three-dimensional model of the acoustic number theory diffuser is simulated by the sound simulation field to generate a simulated sound field distribution heat map. Based on the sound diffusion requirements of the target application scenario, it is determined whether the local thermal transition color of the simulated sound field distribution heat map has shifted compared with the ideal color gamut reference, thereby verifying the design rationality of the acoustic number theory diffuser.

9. The design method of the acoustic number-theoretic diffuser of the composite Helmholtz resonator unit according to claim 8, characterized in that, The process involves calculating the combined impedance of the first and second cavity structures and the acoustic impedance of the third cavity structure using the proposed design parameters from each set of candidate design parameters. This yields the reflection coefficient of the local reactor surface acoustic impedance. Analyzing the reflection coefficient then allows for the determination of the optimal design parameter set for the acoustic number-theoretic diffuser. Specifically, this includes the following steps: Extract the height and width design parameters of the first cavity structure corresponding to the nth acoustic diffusion module in each set of candidate design parameter combinations, and extract the width and depth design parameters of the second cavity structure and the depth design parameters of the third cavity structure. The volume ratio of the first cavity structure to the second cavity structure is calculated based on the height and width design parameters of the first cavity structure and the width design parameter of the second cavity structure. The impedance between the first cavity structure and the second cavity structure is calculated by combining the volume ratio with the depth design parameter of the second cavity structure to obtain the composite impedance. The maximum wavelength value of the target frequency range is obtained. Based on the maximum wavelength value and the depth design parameters of the third cavity structure, the acoustic impedance of the third cavity structure is calculated. The composite impedance and the acoustic impedance are added together to obtain the surface acoustic impedance of the local reactor of the acoustic number theory diffuser. Finally, the reflection coefficient of the surface of the local reactor is determined based on the surface acoustic impedance. If the reflection coefficient is not within the preset range of reflection coefficient values, the candidate design parameter combination is ignored; if it is within the preset range of reflection coefficient values, the candidate design parameter combination is retained, and only the candidate design parameter combination corresponding to the maximum reflection coefficient is extracted and marked as the optimal design parameter group of the acoustic number theory diffuser.

10. The design method of the acoustic number-theoretic diffuser of the composite Helmholtz resonator unit according to claim 8, characterized in that, The construction of a three-dimensional model of an acoustic number-theory diffuser and a sound simulation field for the target application scenario, followed by sound diffusion simulation of the three-dimensional model using the sound simulation field to generate a simulated sound field distribution heatmap, and determining whether the local thermal transition colors of the simulated sound field distribution heatmap have shifted compared to the ideal color gamut reference based on the sound diffusion requirements of the target application scenario, thereby verifying the design rationality of the acoustic number-theory diffuser, specifically includes the following steps: By inputting the optimal design parameter set into the PROE model design software for modeling analysis, a three-dimensional model of an acoustic number theory diffuser suitable for the target application scenario is constructed. Based on big data networks, sound acquisition experience cases of target application scenarios are obtained. Several historical sound environment signals of the target application scenarios in continuous time sequence are extracted through sound acquisition experience cases. Boundary element algorithm is introduced to perform energy rendering on several historical sound environment signals to obtain the sound simulation field of the target application scenario. The three-dimensional model of the acoustic number theory diffuser is imported into the sound simulation field for simulation, and the sound field changes of the three-dimensional model of the acoustic number theory diffuser are recorded when the normal incidence is recorded during the simulation to obtain multiple sets of simulated sound field diffusion data. Based on multiple sets of simulated sound field diffusion data, a sound field distribution heat map of the acoustic number theory diffuser of the composite Helmholtz resonator unit was plotted under normal incidence. This heat map was labeled as a simulated sound field distribution heat map and divided into several two-dimensional diffusion orientation blocks. Based on the acoustic diffusion requirements, the ideal sound field distribution benchmark of the acoustic number theory diffuser is extracted and specified for different two-dimensional diffusion orientation blocks when the diffuser is normally incident in the target application scenario. Based on the ideal sound field distribution benchmark, the transition color gamut specification of the ideal sound field thermodynamic gradient corresponding to different two-dimensional diffusion orientation blocks is established. If the local thermal transition color of the two-dimensional diffusion orientation block in the simulated sound field distribution heat map does not exist in the transition color gamut specification of the corresponding ideal sound field thermal gradient, then mark the two-dimensional diffusion orientation block as an offset diffusion block and obtain the number of offset diffusion blocks in the simulated sound field distribution heat map. If the quantity value is less than the preset quantity threshold, the acoustic number theory diffuser is marked as qualified; otherwise, it is marked as unqualified.

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