Honeycomb-shaped hollow wideband ventilation sound insulation structure and design method thereof

Abstract

The present application relates to the technical field of noise control, in particular to a honeycomb-shaped hollow broadband ventilation sound insulation structure. It comprises a plurality of periodically arranged ventilation sound insulation units; each unit comprises: at least one central honeycomb-shaped ventilation opening; the central honeycomb-shaped ventilation opening contains a plurality of connecting narrow lanes with the same size and shape; an embedded cavity is in communication with the ventilation area located at the center through the connecting narrow lanes; the overall cross section of the ventilation sound insulation unit is square; the ventilation area is a regular hexagonal honeycomb structure; the wall thickness of the ventilation sound insulation unit and the ventilation area is the same; sound waves are incident from the central honeycomb-shaped ventilation opening, a part of which directly passes through the structure, and a part of which enters the embedded cavity from the connecting narrow lanes. The present application can flexibly adjust and control the resonance frequency and the sound insulation bandwidth by adjusting the length of the narrow lane and the thickness of the cavity. By designing a series of multi-layer structure units, the sound insulation bandwidth can be further widened and the overall sound insulation effect can be improved.

Description

Technical Field

[0001] This invention relates to the field of noise control technology, and in particular to a honeycomb-shaped hollowed-out broadband ventilation and sound insulation structure. Background Technology

[0002] Noise pollution is one of the most significant environmental problems we face today. Traditional sound insulation structures, such as thick partition walls or double-layered panels, rely primarily on mass laws or spatial enclosure mechanisms, making them insufficient for modern building sound insulation, ventilation systems for electronic equipment, or noise control devices. The emergence and development of acoustic metamaterials and metasurfaces offer new solutions to the conflict between ventilation and sound insulation. While existing ventilated sound insulation structures can achieve good sound insulation at specific frequencies, they still have significant limitations in balancing low-frequency broadband performance, structural thickness, and ventilation efficiency. In particular, most structures require substantial structural thickness to achieve broadband sound insulation, or at the cost of sacrificing ventilation efficiency. Furthermore, the acoustic performance of existing structures is typically fixed after design and manufacturing, making it difficult to flexibly adjust to the needs of actual applications. Structural complexity is also a major factor restricting their practical application and promotion; complex internal structures not only increase manufacturing difficulty and cost but also limit their practical application and promotion. Therefore, ventilated sound insulation structures still face limitations in balancing low-frequency broadband performance, structural thickness, and ventilation efficiency. Summary of the Invention

[0003] The purpose of this invention is to address the problems existing in the background technology by proposing a honeycomb-shaped hollowed-out broadband ventilation and sound insulation structure.

[0004] The technical solution of the present invention, in its first aspect, provides a honeycomb-shaped hollowed-out wide-band ventilation and sound insulation structure, comprising a plurality of periodically arranged ventilation and sound insulation units; each unit includes: At least one central honeycomb-shaped vent; the central honeycomb-shaped vent includes a plurality of connecting narrow channels of the same size and shape; An embedded cavity is connected to a centrally located ventilation area via the connecting narrow passage; The ventilation and sound insulation unit has a square cross-section with a side length of A; the ventilation area has a regular hexagonal honeycomb structure with a side length of a; the ventilation and sound insulation unit and the ventilation area have the same wall thickness of t. Sound waves enter through the central honeycomb-shaped vent, with some passing directly through the structure and others entering the embedded cavity through the connecting narrow channel.

[0005] Preferably, within the sound insulation operating frequency band, the pressure between the central ventilation area and the embedded cavity is anti-symmetrically distributed and phase-opposite; The sound pressure at the narrow passage exhibits a transitional mode: that is, the part near the central honeycomb vent shows a positive pressure phase, while the part near the embedded cavity shows a negative pressure phase; forming a Fano-like resonance effect, achieving ultra-wideband ventilation and sound insulation.

[0006] Preferably, in the periodically arranged ventilation and sound insulation units, each unit has the same geometric dimensions, and the number of units arranged is determined according to the actual application requirements.

[0007] Preferably, the length of the connecting narrow channel is w, the thickness is H, and the width d is calculated using the following formula: ; In the formula, a is the side length of the regular hexagonal honeycomb structure of the ventilation area, w is the length of the connecting narrow channel, and t is the wall thickness of the ventilation area.

[0008] Preferably, the cross-sectional area S of the embedded cavity is calculated using the following formula: ; In the formula, A is the side length of the ventilation and sound insulation unit, and a is the side length of the regular hexagonal honeycomb structure in the ventilation area; The thickness of the embedded cavity is L, and its volume is... The total structural thickness is the same as the thickness of the connecting narrow passage, both being H, and is calculated according to the following formula: .

[0009] Preferably, the connecting narrow channel is equivalent to acoustic quality and acoustic resistance, while the embedded cavity is equivalent to acoustic compliance; Several connecting narrow channels are all connected to a common embedded cavity; in the acoustic-electric analog equivalent circuit, the acoustic quality and acoustic resistance of several channels are equivalent to being connected to the same acoustic compliance.

[0010] Preferably, when multiple periodically arranged ventilation and sound insulation units are arranged in a single layer, they are used to achieve narrow-band high-efficiency sound insulation and broadband ventilation and sound insulation at the resonant frequency.

[0011] Preferably, when multiple periodically arranged ventilation and sound insulation units are arranged in series at intervals along the sound propagation direction in multiple layers, it is used to expand the sound insulation bandwidth and improve the overall broadband sound insulation performance. Multiple units are spaced D apart, and each unit layer has a different cavity thickness L and narrow channel length w.

[0012] A second aspect of the present invention provides a design method for a honeycomb-shaped perforated broadband ventilation and sound insulation structure, used to design the aforementioned ventilation and sound insulation structure. The ventilation and sound insulation structure is suitable for ventilation noise control applications, including traffic noise barriers and air conditioning noise control. The ventilation rate Q of the ventilation and sound insulation structure is freely set according to actual needs and determined by the following formula:

[0013] In the formula, S is the cross-sectional area of ​​the embedded cavity, and A is the side length of the ventilation and sound insulation unit; When designing the basic unit, first determine the value of ventilation rate Q, then design the appropriate positive direction unit side length A according to the requirements of target noise frequency band, size limit, etc., then determine the side length a of the honeycomb ventilation opening according to the formula of relationship between ventilation rate and structural size, and then determine the length w of the connecting narrow channel (2) and the thickness L of the embedded cavity (3); While keeping A and a constant, the resonant frequency and sound insulation bandwidth of the ventilation and sound insulation unit are controlled by adjusting the length w of the connecting narrow channel (2) and the thickness L of the embedded cavity (3). When setting the w parameter, the limitation of the side length a needs to be considered to ensure that the width d of the narrow channel is appropriate. When w increases, the resonant frequency and the corresponding sound insulation working frequency band shift to lower frequencies, and the overall sound insulation amount does not change significantly. When L increases, the resonant frequency and the corresponding sound insulation working frequency band shift to lower frequencies, and the overall sound insulation amount is also improved.

[0014] Compared with the prior art, the present invention has the following beneficial technical effects: 1. In this invention, the ventilation and sound insulation unit consists of a central honeycomb-shaped ventilation opening containing three narrow channels and an embedded cavity, which are connected by the narrow channels. The narrow channels are semi-open necks, forming a Helmholtz-like resonator with the cavity, which can achieve a layer-by-layer sound attenuation effect; 2. The ventilation and sound insulation unit not only exhibits narrow-band high sound insulation performance near the resonant frequency, but also has ultra-wideband sound insulation performance; 3. By adjusting the size of the narrow channel and the thickness of the cavity, the sound insulation operating frequency band can be adjusted; 4. By designing a multi-layer unit structure with different operating frequencies in series, the sound insulation bandwidth can be expanded and the overall broadband sound insulation performance can be improved.

[0015] 5. The honeycomb hollow structure designed in this invention has key structural dimension adjustment parameters (narrow channel size and cavity thickness) that are exposed and visible. It has the characteristics of simple structure and easy processing and manufacturing, and is suitable for promotion and application in practical engineering applications. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the unit structure and periodic array arrangement of the present invention; Figure 2 This is a cross-sectional view of the structural unit of the present invention, including the direction of sound wave propagation and the structural parameters of the structural layer; Figure 3 This is a cross-sectional view of the multilayer series unit distribution of the present invention; Figure 4 This is an experimental diagram of the sound insulation test using the four-microphone method with acoustic impedance tubes according to the present invention. Figure 5 This is a diagram of the test sample for the present invention; Figure 6 This is a frequency-sound insulation curve of a unit simulation result in an embodiment of the present invention. Figure 7 This is a frequency-sound insulation curve of the simulation results of the three-unit series connection in an embodiment of the present invention.

[0017] Reference numerals in the attached drawings: 1. Central honeycomb-shaped vent; 2. Connecting narrow channel; 3. Embedded cavity; 4. First multi-layer interval; 5. Second multi-layer interval; 6. First series unit; 7. Second series unit; 8. Third series unit. Detailed Implementation Example

[0018] like Figure 1 As shown, the honeycomb-shaped perforated broadband ventilation and sound insulation structure proposed in this embodiment includes multiple periodically arranged ventilation and sound insulation units; each unit includes: At least one central honeycomb-shaped vent 1; the central honeycomb-shaped vent 1 includes several connecting narrow channels 2 of the same size and shape; an embedded cavity 3, which is connected to the ventilation area located at the center through the connecting narrow channels 2; the overall cross-section of the ventilation and sound insulation unit is square with a side length of A; the ventilation area is a regular hexagonal honeycomb structure with a side length of a; the wall thickness of the ventilation and sound insulation unit and the ventilation area are the same, with a wall thickness of t; sound waves are incident from the central honeycomb-shaped vent 1, part of which passes directly through the structure, and part of which enters the embedded cavity 3 through the connecting narrow channels 2.

[0019] In this embodiment, within the sound insulation operating frequency band, the pressure between the central ventilation area and the embedded cavity 3 is anti-symmetrically distributed and in opposite phase; the sound pressure at the connecting narrow channel 2 presents a transition mode: that is, the part near the central honeycomb vent 1 shows a positive pressure phase, and the part near the embedded cavity 3 shows a negative pressure phase; forming a Fano-like resonance effect, achieving ultra-wideband ventilation and sound insulation.

[0020] This embodiment discloses a honeycomb-shaped perforated broadband ventilation and sound insulation structure for achieving ultra-wideband sound insulation under ventilation conditions. The structure consists of an array of multiple identical honeycomb-shaped perforated units. Each unit comprises a central honeycomb-shaped vent containing three narrow channels and an embedded cavity, connected by these narrow channels. This structure is based on a Fano-like resonance mechanism: a portion of the sound wave, as a broadband "continuous state," passes directly through the ventilation channel; another portion, as a narrowband "discrete state," enters the cavity and generates strong resonance. When excited at the resonant frequency, the two sound waves generate a phase difference of π radians and undergo destructive interference, thereby forming a high sound insulation peak near that frequency.

[0021] The unit exhibits both high sound insulation performance and effective broadband sound insulation capabilities at resonance. By adjusting the key parameters—narrow channel length *w* and embedded cavity thickness *L*—the resonant frequency and operating bandwidth of the structure can be effectively controlled. To further extend the sound insulation bandwidth, multiple units with different resonant frequencies can be arranged in series along the sound propagation direction. Through synergistic coupling of multiple layers of units, the overall broadband sound insulation performance can be enhanced. In one preferred embodiment, in the periodically arranged ventilation and sound insulation units, each unit has the same geometric dimensions, and the number of units arranged is determined according to the actual application requirements.

[0022] The length of the connecting narrow passage 2 is w, and its thickness is H; the width d is calculated using the following formula: ; In the formula, a is the side length of the regular hexagonal honeycomb structure of the ventilation area, w is the length of the connecting narrow channel 2, and t is the wall thickness of the ventilation area.

[0023] The cross-sectional area S of the embedded cavity 3 is calculated using the following formula: ; In the formula, A is the side length of the ventilation and sound insulation unit, and a is the side length of the regular hexagonal honeycomb structure in the ventilation area; The thickness of the embedded cavity 3 is L, and its volume is... The total thickness of the structure is the same as the thickness of connecting narrow passage 2, both being H, and is calculated according to the following formula: .

[0024] The connecting narrow channel 2 is equivalent to acoustic quality and acoustic resistance, while the embedded cavity 3 is equivalent to acoustic compliance; Several connecting narrow channels 2 are all connected to a common embedded cavity 3; in the acoustic-electric analog equivalent circuit, the acoustic quality and acoustic resistance of several channels are equivalent to being connected to the same acoustic compliance.

[0025] The resonant frequency and sound insulation bandwidth of the ventilation and sound insulation unit can be controlled by adjusting the length w of the connecting narrow channel 2 and the thickness L of the embedded cavity 3. The maximum value of the narrow channel length w is limited by the side length a of the honeycomb shape, and it should not be too small, ensuring that the narrow channel width d>0 within a reasonable parameter range. If W is too large, d>0 must be ensured. Increasing w can adjust the structure to shift the resonant frequency to a lower frequency; increasing L can shift the resonant frequency of the unit to a lower frequency while improving the sound insulation in the wide range. When multiple periodically arranged ventilation and sound insulation units are set up in a single layer, both narrow-band high-efficiency ventilation and sound insulation and wide-band ventilation and sound insulation at the resonant frequency can be achieved.

[0026] To further clarify the technical solution of this embodiment, the technical effect of this embodiment is verified through analytical derivation, numerical simulation, parameter optimization, and experimental verification, as follows: like Figure 2 The figure shown is a cross-sectional view of the single-layer structure of the present invention, consisting of a central honeycomb-shaped vent containing three narrow channels and an embedded cavity. The sound propagation direction and airflow direction are indicated by the arrows in Figure 2.

[0027] Set the geometric parameters and dimensions of the designed structure, as shown in Table 1: Table 1 Geometric Parameter Dimension Table

[0028] Simulation results show that the unit resonates at 1410 Hz, with a peak sound insulation level (STL) exceeding 35 dB, and maintains an average STL of approximately 10 dB across the ultra-wideband frequency range of 1330-2500 Hz, demonstrating excellent broadband sound insulation performance. The structure is only 23 mm thick. Example

[0029] like Figure 3 As shown, the honeycomb-shaped hollow broadband ventilation and sound insulation structure proposed in this embodiment differs from that in Embodiment 1. In this embodiment, multiple periodically arranged ventilation and sound insulation units are arranged in series at intervals along the sound propagation direction to achieve the expansion of the sound insulation bandwidth and the improvement of the overall broadband sound insulation performance. The multi-layer interval 4 between the multiple units is D, and each layer of units has a different cavity thickness L and narrow channel length w.

[0030] To achieve wider bandwidth noise control, the sound insulation bandwidth is broadened, and the overall broadband sound insulation performance is improved. Three units are arranged in series along the sound incident direction to form a multi-layer structure. The three units (first series unit 6, second series unit 7, and third series unit 8) are arranged at a certain interval D, connected by the first multi-layer interval 4 and the second multi-layer interval 5, where D = 2mm. Figure 3 As shown in Table 2, while keeping other parameters consistent with Example 1, the cavity thickness L and narrow channel length w (n=1, 2, 3) of each layer unit were adjusted to have different values. Table 2 Geometric Parameter Dimension Table

[0031] This multi-layered structure achieves a 30% ventilation rate, a total thickness of 53mm, and an average sound insulation of over 15dB in the 1100–2500 Hz range, thus realizing ultra-wideband ventilation and sound insulation.

[0032] We used COMSOL Multiphysics 6.2 software to perform frequency domain simulation analysis on the designed ventilation and sound insulation unit to analyze its sound insulation performance. Because the impedance of solids and air differs significantly by orders of magnitude, we simplified the solid part as an acoustic hard boundary and only simulated the air domain. We set the air density... speed of sound The air domain was set as a pressure acoustic physics field. In the simulation, the incident sound wave was set as a plane wave with an amplitude of 1 Pa, propagating along the positive x-axis. The incident and exit ends of the model were both set as plane wave radiation boundary conditions.

[0033] The transmission coefficient T and reflection coefficient R of a sound wave can be expressed as:

[0034] in For the incident sound intensity, This refers to the transmitted sound intensity. This represents the reflected sound intensity. In the simulation model, the corresponding sound intensity value can be measured by setting boundary probes.

[0035] Sound energy transfer loss STL (dB)

[0036] Experimental verification: To further verify the sound insulation performance of the proposed ventilation and sound insulation structure, the sound transmission loss (STL) was measured using the acoustic impedance tube four-microphone method. A schematic diagram of the experimental setup is shown below. Figure 4 As shown. To match the 102 mm × 102 mm cross-sectional size of the square test acoustic impedance tube, a 2×2 multi-array unit sample was fabricated. The 3D printed sample is shown below. Figure 5 As shown.

[0037] The experimental data and simulation results agree well, proving the effectiveness and reliability of the design method of this invention. The provided design scheme is complete and feasible, and can guide practical engineering applications.

[0038] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited thereto. Various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention.

Claims

1. A honeycomb-shaped perforated wide-band ventilation and sound insulation structure, characterized in that, It includes multiple periodically arranged ventilated and soundproof units; each unit includes: At least one central honeycomb vent (1); the central honeycomb vent (1) includes several connecting narrow channels (2) of the same size and shape. An embedded cavity (3) is connected to a central ventilation area via the connecting narrow channel (2); The ventilation and sound insulation unit has a square cross-section with a side length of A; the ventilation area has a regular hexagonal honeycomb structure with a side length of a; the ventilation and sound insulation unit and the ventilation area have the same wall thickness of t. Sound waves enter from the central honeycomb-shaped vent (1), part of which passes directly through the ventilation and sound insulation structure, and part of which enters the embedded cavity (3) through the connecting narrow channel (2); Within the sound insulation operating frequency band, the pressure between the central ventilation area and the embedded cavity (3) is anti-symmetrically distributed and phase-opposite; The sound pressure at the narrow passage (2) presents a transitional mode: that is, the part near the central honeycomb vent (1) shows a positive pressure phase, and the part near the embedded cavity (3) shows a negative pressure phase; forming a Fano-like resonance effect, achieving ultra-wideband ventilation and sound insulation.

2. The honeycomb-shaped perforated wide-band ventilation and sound insulation structure according to claim 1, characterized in that, In the periodically arranged ventilation and sound insulation units, each unit has the same geometric dimensions, and the number of units arranged is determined according to the actual application requirements.

3. The honeycomb-shaped perforated wide-band ventilation and sound insulation structure according to claim 1, characterized in that, The length of the connecting narrow passage (2) is The thickness is H; the width d is calculated using the following formula: ； In the formula, a is the side length of the regular hexagonal honeycomb structure of the ventilation area, w is the length of the connecting narrow channel (2), and t is the wall thickness of the ventilation area.

4. The honeycomb-shaped perforated wide-band ventilation and sound insulation structure according to claim 1, characterized in that, The cross-sectional area S of the embedded cavity (3) is calculated using the following formula: ； In the formula, A is the side length of the ventilation and sound insulation unit, and a is the side length of the regular hexagonal honeycomb structure in the ventilation area; The thickness of the embedded cavity (3) is ,volume The total thickness of the structure is the same as the thickness of the connecting narrow channel (2), both being H, and is calculated according to the following formula: 。 5. A honeycomb-shaped perforated wide-band ventilation and sound insulation structure according to claim 1, characterized in that, The ventilation and sound insulation structure is suitable for ventilation noise control applications, including traffic noise and air conditioning noise.

6. The honeycomb-shaped perforated wide-band ventilation and sound insulation structure according to claim 1, characterized in that, The connecting narrow channel (2) is equivalent to acoustic quality and acoustic resistance, while the embedded cavity (3) is equivalent to acoustic compliance; Several connecting narrow channels (2) are all connected to a common embedded cavity (3); in the acoustic-electric analog equivalent circuit, the acoustic quality and acoustic resistance of several channels are equivalent to being connected to the same acoustic compliance.

7. A honeycomb-shaped perforated wide-band ventilation and sound insulation structure according to claim 1, characterized in that, When multiple periodically arranged ventilation and sound insulation units are set up in a single layer, they are used to achieve narrow-band high-efficiency sound insulation and broadband ventilation and sound insulation at the resonant frequency.

8. A honeycomb-shaped perforated wide-band ventilation and sound insulation structure according to claim 1, characterized in that, When multiple periodically arranged ventilation and sound insulation units are connected in series at intervals along the sound propagation direction and arranged in multiple layers, it is used to expand the sound insulation bandwidth and improve the overall broadband sound insulation performance. Multiple units, spaced D apart, with each unit layer having a different cavity thickness. and narrow passage length .

9. A design method for a honeycomb-shaped perforated wide-band ventilation and sound insulation structure, used to design the ventilation and sound insulation structure according to any one of claims 1-8, characterized in that, The ventilation rate Q of the ventilation and sound insulation structure can be freely set according to actual needs and is determined by the following formula: ； In the formula, S is the cross-sectional area of ​​the embedded cavity, and A is the side length of the ventilation and sound insulation unit; When designing the basic unit, first determine the value of ventilation rate Q, then design the appropriate positive direction unit side length A according to the target noise frequency band and size limitation requirements, then determine the side length a of the honeycomb ventilation opening according to the formula of the relationship between ventilation rate and structural size, and then determine the length w of the connecting narrow channel (2) and the cavity thickness L of the embedded cavity (3); While keeping A and a constant, the resonant frequency and sound insulation bandwidth of the ventilation and sound insulation unit are controlled by adjusting the length w of the connecting narrow channel (2) and the cavity thickness L of the embedded cavity (3). When setting the w parameter, the limitation of the side length a needs to be considered to ensure that the width d of the narrow channel is appropriate. When w increases, the resonant frequency and the corresponding sound insulation working frequency band shift to lower frequencies, and the overall sound insulation amount does not change significantly. When the cavity thickness L increases, the resonant frequency and the corresponding sound insulation working frequency band shift to lower frequencies, and the overall sound insulation amount is also improved.

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