Fan-type ventilation sound insulation device and acoustic barrier based on Helmut Holtz resonance cavity

Abstract

The present invention discloses a fan-type ventilation sound insulation device and an acoustic barrier based on a Helmut Holtz resonant cavity. The fan-type ventilation sound insulation device comprises a main body and a plurality of microcavity structural units. The microcavity structural units are axially symmetrically distributed around the outside of the main body along the circumference of the main body, and the distances between adjacent microcavity structural units are the same. The microcavity structural units include resonant cavity units, narrow neck units, and small arc-shaped units. There are slots between adjacent narrow neck units, between adjacent resonant cavity units, and between narrow neck units and resonant cavity units in the microcavity structural units. The acoustic barrier is composed of a plurality of fan-type ventilation sound insulation devices arranged in a periodic manner. The fan-type ventilation sound insulation device and acoustic barrier designed by the present invention have better sound insulation effect in the low-frequency band, can achieve sound insulation at low-frequency resonant frequencies while ensuring ventilation, and have good ventilation performance, a compact structure, and are easy to process, thus having broad application prospects.

Description

Technical Field

[0001] The present invention relates to the field of a new generation of acoustic devices, in particular to a fan-type ventilation and sound insulation device based on a Helmut Holtz resonance cavity, and also to an acoustic barrier. Background Art

[0002] Low-frequency noise (ranging from 200Hz to 2000Hz) has the characteristics of long propagation distance, slow energy decay, and strong diffraction, impacting people's quality of life and working environment. Conventional sound insulation methods mostly use closed structures, such as solid walls or sound-absorbing panels. While these can block noise to a certain extent, they also hinder air circulation, hindering heat exchange and airflow. Therefore, in scenarios such as subway vents and equipment room entrances and exits, where both sound insulation and ventilation efficiency are crucial, traditional structures are difficult to meet practical requirements.

[0003] To this end, some integrated ventilation and sound insulation structural design schemes have emerged in recent years. Among them, ventilation and sound insulation structures based on the Helmholtz resonance cavity principle have attracted widespread attention because they can absorb sound waves in a specific frequency band. This type of structure mainly includes the following typical forms: (1) Planar array Helmholtz resonance structure, which attenuates specific frequency sound waves by setting a periodic resonance cavity array, but its structural volume is large, the air flow channel is narrow, and the ventilation efficiency is limited; (2) Spiral or maze acoustic structure, which uses the phase delay effect brought about by the extension of the sound wave propagation path to achieve sound insulation, but its processing is complex, the structure is large, and the low-frequency performance is still limited; (3) Folding structure design, which increases the structural length by spatial folding to obtain a lower resonance frequency, but usually brings problems such as increased air flow resistance and poor structural control accuracy.

[0004] Overall, existing ventilation and sound insulation structures still have the following problems: First, the sound insulation effect in the low-frequency range (200Hz-500Hz) is not ideal, making it difficult to meet the noise reduction requirements of practical applications; second, the ventilation efficiency is low, and it cannot achieve both sound insulation and ventilation performance; third, the structure is complex and difficult to manufacture, which is not conducive to mass engineering application. Therefore, there is an urgent need for a new ventilation and sound insulation device that has better sound insulation effect in the low-frequency range, good ventilation performance, and a compact and easy-to-manufacture structure. Summary of the Invention

[0005] The purpose of the present invention is to provide a fan-type ventilation sound insulation device and acoustic barrier based on the Helvetic Holtz resonance cavity. By optimizing the shape and structural layout of the resonance cavity, effective sound insulation in the low-frequency band is achieved while maintaining good air circulation performance, and the device has broad application prospects.

[0006] To achieve the above functions, the present invention designs a fan-type ventilation and sound insulation device based on a Helholtz resonant cavity. The fan-type ventilation and sound insulation device is fixed to a substrate, and the space within a preset range from the upper and lower surfaces of the substrate is a cavity. The fan-type ventilation and sound insulation device includes a main body 1 and a plurality of microcavity structural units. The cross-sectional shape of each microcavity structural unit is the same. The microcavity structural units are axially symmetrically arranged around the outside of the main body 1 along the circumference of the main body 1, and the distance between adjacent microcavity structural units is the same. The microcavity structural units include a resonant cavity unit 2, a narrow neck unit 3, and a small arc unit 4.

[0007] The narrow neck unit 3 is located on one side of the resonant cavity unit 2. One end of the narrow neck unit 3 is fixedly connected to the resonant cavity unit 2 via the small arc unit 4, and the other end is fixedly connected to the main body 1. The thickness of the narrow neck unit 3 is smaller than that of the resonant cavity unit 2.

[0008] There are slots between adjacent narrow-necked units 3, between adjacent resonant cavity units 2, and between the narrow-necked units 3 and the resonant cavity units 2 in the microcavity structure unit, and the small arc-shaped unit 4 is fixedly connected to the main body 1; each resonant cavity unit 2 and each slot has a certain opening angle, and the width gradually increases along the direction away from the main body 1, and the opening angle of each resonant cavity unit 2 is the same; the opening angle of the slot 5 between adjacent resonant cavity units 2, the opening angle of the slot between adjacent narrow-necked units 3, and the opening angle of the slot between the narrow-necked unit 3 and the resonant cavity unit 2 are the same.

[0009] As a preferred technical solution of the present invention: the main body 1 is cylindrical.

[0010] As a preferred technical solution of the present invention: the thickness of the main body 1 is greater than the thickness of each microcavity structural unit.

[0011] As a preferred technical solution of the present invention: along the counterclockwise direction of the main body 1, the thickness of the resonant cavity unit 2 in each microcavity structure unit increases successively.

[0012] As a preferred technical solution of the present invention: the thickness of the resonant cavity unit 2 in the microcavity structure unit is in the range of 0.24 cm to 1.9 cm.

[0013] As a preferred technical solution of the present invention: the number of the microcavity structure units ranges from 4 to 8.

[0014] As a preferred technical solution of the present invention, the slot angles between adjacent resonant cavity units 2, the slot angles between adjacent narrow neck units 3, and the slot angles between the narrow neck unit 3 and the resonant cavity unit 2 are all 2 degrees.

[0015] As a preferred technical solution of the present invention, the narrow neck unit 3 has a certain opening angle, the width gradually increases along the direction away from the main body 1, and the opening angle of each narrow neck unit 3 is the same.

[0016] As a preferred technical solution of the present invention: the angle range of the three angles of the narrow neck unit is 4 degrees to 8 degrees.

[0017] The present invention also designs an acoustic barrier, which uses the fan-type ventilation and sound insulation device based on the Helmut Holtz resonance cavity as a basic unit, splices the substrates of multiple fan-type ventilation and sound insulation devices with each other, and arranges the fan-type ventilation and sound insulation devices periodically in the horizontal and vertical directions.

[0018] Beneficial effects: Compared with the prior art, the advantages of the present invention include:

[0019] The present invention designs a fan-type ventilation sound insulation device and acoustic barrier with a Helvetic Holtz resonance cavity. By utilizing the resonance effect of a thickness-gradient microcavity structure, a low-frequency sound insulation effect can be achieved at a subwavelength scale. The acoustic barrier has good sound insulation effect and can maintain air circulation well, which is of great significance for the design and application of a new generation of acoustic devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 1 is a schematic structural diagram of a fan-type ventilation and sound insulation device based on a Helholtz resonance cavity according to an embodiment of the present invention;

[0021] Figure 1 Middle: 1. Main body; 2. Resonant cavity unit; 3. Narrow neck unit; 4. Small arc unit; 5. Empty slot;

[0022] Figure 2 is a schematic structural diagram of a microcavity structure unit provided according to an embodiment of the present invention;

[0023] Figure 3 is a perspective view of a fan-type ventilation and sound insulation device based on a Helholtz resonance cavity according to an embodiment of the present invention;

[0024] Figure 4 is a three-dimensional diagram of a microcavity structure unit provided according to an embodiment of the present invention;

[0025] Figure 5 is a distribution diagram of resonance modes in a microcavity structure at a resonance frequency of 309 Hz provided by an embodiment of the present invention;

[0026] Figure 6 is a distribution diagram of resonance modes in a microcavity structure at a resonance frequency of 376 Hz provided by an embodiment of the present invention;

[0027] Figure 7 is a distribution diagram of resonance modes in a microcavity structure at a resonance frequency of 436 Hz provided by an embodiment of the present invention;

[0028] Figure 8is a distribution diagram of resonance modes in a microcavity structure at a resonance frequency of 507 Hz provided by an embodiment of the present invention;

[0029] Figure 9 is a schematic diagram of a practical application scenario of an acoustic barrier provided according to an embodiment of the present invention;

[0030] Figure 10 3 is a transmission coefficient spectrum of the acoustic barrier provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0032] An embodiment of the present invention provides a fan-type ventilation and sound insulation device based on a Helholtz resonant cavity. The fan-type ventilation and sound insulation device is fixed on a substrate, and the space within a preset range from the upper surface and the lower surface of the substrate is a cavity. The fan-type ventilation and sound insulation device includes a main body 1 and a plurality of microcavity structural units. The main body and the microcavity structural units are resin structures, and samples can be prepared using 3D printing technology. The main body 1 is cylindrical, and the thickness of the main body 1 is greater than the thickness of each microcavity structural unit. The radius of the main body 1 ranges from 0.5 cm to 2 cm. In one embodiment, the radius of the main body 1 is 1 cm.

[0033] Each microcavity structure unit has the same cross-sectional shape, and the microcavity structure unit surrounds the outer side of the main body 1 in an axisymmetric manner along the circumference of the main body 1, and the distance between adjacent microcavity structure units is the same; the microcavity structure unit includes a resonant cavity unit 2, a narrow neck unit 3, and a small arc unit 4;

[0034] The narrow neck unit 3 is located on one side of the resonant cavity unit 2. One end of the narrow neck unit 3 is fixedly connected to the resonant cavity unit 2 via the small arc unit 4, and the other end is fixedly connected to the main body 1. The thickness of the narrow neck unit 3 is smaller than that of the resonant cavity unit 2.

[0035] Along the counterclockwise direction of the main body 1, the thickness of the resonance cavity unit 2 in each microcavity structure unit increases successively; there are slots between adjacent narrow neck units 3, between adjacent resonance cavity units 2, and between the narrow neck units 3 and the resonance cavity units 2 in the microcavity structure unit to form an air channel, and the small arc-shaped unit 4 is fixedly connected to the main body 1; each resonance cavity unit 2 and each slot has a certain opening angle, and the width gradually increases along the direction away from the main body 1, and the angle of each resonance cavity unit 2 is the same; the angle of the slot 5 between adjacent resonance cavity units 2, the angle of the slot between adjacent narrow neck units 3, and the angle of the slot between the narrow neck unit 3 and the resonance cavity unit 2 are the same.

[0036] The number of the microcavity structure units ranges from 4 to 8; the thickness of the resonance cavity unit 2 in the microcavity structure unit ranges from 0.24 cm to 1.9 cm.

[0037] The angles of the slots 5 between adjacent resonant cavity units 2, the angles of the slots between adjacent narrow neck units 3, and the angles of the slots between the narrow neck unit 3 and the resonant cavity unit 2 are all 2 degrees.

[0038] The narrow neck unit 3 has a certain opening angle, and the width gradually increases along the direction away from the main body 1. The opening angle of each narrow neck unit 3 is the same, and the opening angle range of the narrow neck unit 3 is 4 degrees to 8 degrees.

[0039] Reference Figure 1 In one embodiment, the number of microcavity structural units is 8, wherein the angle of the narrow neck unit 3 is 4 degrees, the angle of each resonant cavity unit 2 is 37 degrees, the angle of the slot 5 between adjacent resonant cavity units 2, the angle of the slot between adjacent narrow neck units 3, and the angle of the slot between a narrow neck unit 3 and a resonant cavity unit 2 are 2 degrees; the resonant cavity unit 2 is a trapezoid with a non-parallel upper and lower bases. Figure 1 In the equation, w represents the side length of the substrate, h3 represents the distance between the edge of the substrate and the microcavity structure unit, l 1 represents the length of the narrow neck unit 3. In one embodiment, l 1=2.5cm; r is the radius of the body 1.

[0040] Reference Figure 2 One end of the narrow neck unit 3 is connected to the hypotenuse of the resonant cavity unit 2 through a small arc unit 4. The length of the small arc unit 4 is h4. In one embodiment, h4=0.5mm. The thickness of the small arc unit 4 is the same as that of the main body 1.

[0041] Reference for the stereogram of the fan-type ventilation and sound insulation device based on the Helmut Holtz resonance cavity Figure 3 , the stereogram of the microcavity structure unit is referenced Figure 4 , Figure 3 In the embodiment, the thickness of the main body 1 is 2h1, the distance between the top surface of the main body 1 and the top surface of the cavity, and the distance between the bottom surface of the main body 1 and the bottom surface of the cavity are both 2h1, and the thickness of the entire cavity is 6h1; Figure 4 In the embodiment, the thickness of the narrow neck unit 3 is 2h2. In one embodiment, h2=0.3 cm. The thicknesses of the resonant cavity units 2 in the counterclockwise direction along the circumference of the main body 1 are 2d0, 2d1, 2d2, 2d3, 2d4, 2d5, 2d6, and 2d7 respectively.

[0042] In one embodiment, d0 to d7 are respectively: 、 、 、 、 、 、 、 .

[0043] The microcavity structure unit design is the key to achieving subwavelength multi-frequency resonance in the present invention, and a single microcavity structure unit supports multiple low-order resonance modes at the same time, which is of fundamental importance for realizing the design of omnidirectional ventilated acoustic barrier structures in the low-frequency band.

[0044] The fan-type ventilation sound insulation device designed in this invention operates as follows: When sound waves enter a microcavity structure unit with a gradient thickness, the resonant cavity units 2 of varying thickness excite low-order resonant modes at their corresponding frequencies, thereby absorbing and dissipating the sound wave energy, achieving multi-band sound wave suppression. Because these units possess subwavelength characteristics, they can achieve multi-frequency sound isolation within a relatively small structural scale. The resonant cavity unit 2 is responsible for the primary storage and resonance of sound energy, the narrow-necked unit 3 restricts air exchange and enhances resonant coupling, and the small arc-shaped unit 4 serves as a transitional connection and maintains a continuous air channel.

[0045] Figures 5 to 8 These are the resonance mode distribution diagrams in the microcavity structure at resonance frequencies of 309Hz, 376Hz, 436Hz, and 507Hz respectively.

[0046] The embodiment of the present invention also provides an acoustic barrier, which uses the fan-type ventilation and sound insulation device based on the Helmut Holtz resonance cavity as a basic unit, splices the substrates of multiple fan-type ventilation and sound insulation devices together, and arranges the fan-type ventilation and sound insulation devices in a periodic arrangement in the horizontal and vertical directions. Figure 9 , the transmission coefficient spectrum of the acoustic barrier refers to Figure 10 .

[0047] In summary, the present invention proposes a fan-type ventilation sound insulation device and acoustic barrier based on the Helmut Holtz resonance cavity, the core of which lies in a microcavity structural unit with a thickness gradient feature. The structure consists of a plurality of resonance cavity units distributed in the circumferential direction of the main body. Each resonance cavity unit gradually changes its cavity thickness in the circumferential direction while maintaining the symmetry of the overall structure, so that different units have different effective resonance lengths and cavity volumes. This angular thickness gradient design enables a single subwavelength structural unit to simultaneously excite low-order resonance modes at multiple frequency points, thereby achieving multi-band or even wide-band sound wave suppression capabilities. By finely controlling the cavity length, width and cavity thickness, efficient sound energy capture performance can be obtained at a smaller structural scale, with significant sound insulation effect. In addition, the structure adopts a hollow ventilation design, which effectively suppresses low-frequency noise while maintaining natural air circulation. It is suitable for practical scenarios such as urban traffic air ducts, subway entrances and exits, and ventilation equipment rooms that have high requirements for ventilation and sound insulation performance. Numerical simulations and emulation results demonstrate that the structure achieves stable acoustic energy suppression across multiple low-frequency bands, and its sound insulation peak can be flexibly adjusted by adjusting geometric parameters. The invention also offers excellent scalability and customizability. Users can customize the desired sound insulation performance and ventilation capacity by adjusting parameters such as the number of resonant cavity units, their angular distribution, and the thickness gradient, depending on the target frequency range. This provides a novel and efficient solution for the design of multi-band broadband sound insulation devices.

[0048] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the scope of knowledge possessed by ordinary technicians in this field without departing from the spirit of the present invention.

Claims

1. A fan-type ventilation and sound insulation device based on a Helmut Holtz resonance cavity, characterized in that: The fan-type ventilation sound insulation device is fixed on a substrate, and the space within a preset range from the upper surface and the lower surface of the substrate is a cavity; the fan-type ventilation sound insulation device comprises a main body (1), and a plurality of microcavity structure units; the cross-sectional shapes of the microcavity structure units are the same, the microcavity structure units are arranged around the outside of the main body (1) in an axisymmetric manner along the circumference of the main body (1), and the distances between adjacent microcavity structure units are the same; the microcavity structure units comprise a resonant cavity unit (2), a narrow neck unit (3), and a small arc unit (4); The thin neck unit (3) is located on one side of the resonant cavity unit (2), one end of the thin neck unit (3) is fixedly connected to the resonant cavity unit (2) via the small arc unit (4), and the other end is fixedly connected to the main body (1), and the thickness of the thin neck unit (3) is smaller than that of the resonant cavity unit (2); There are slots between adjacent narrow neck units (3), between adjacent resonant cavity units (2), and between the narrow neck units (3) and the resonant cavity units (2) in the microcavity structure unit; each resonant cavity unit (2) and each slot has a certain opening angle, and the width gradually increases along the direction away from the main body (1), and the angle of the opening angle of each resonant cavity unit (2) is the same; the angle of the slot (5) between adjacent resonant cavity units (2), the angle of the slot between adjacent narrow neck units (3), and the angle of the slot between the narrow neck unit (3) and the resonant cavity unit (2) are the same.

2. The fan-type ventilation and sound insulation device based on the Helmut Holtz resonance cavity according to claim 1, characterized in that: The main body (1) is cylindrical.

3. The fan-type ventilation and sound insulation device based on the Helmut Holtz resonance cavity according to claim 1, characterized in that: The thickness of the main body (1) is greater than the thickness of each microcavity structural unit.

4. The fan-type ventilation and sound insulation device based on the Helmut Holtz resonance cavity according to claim 1, characterized in that: Along the counterclockwise direction of the main body (1), the thickness of the resonance cavity unit (2) in each microcavity structure unit increases in sequence.

5. The fan-type ventilation and sound insulation device based on the Helmut Holtz resonance cavity according to claim 4, characterized in that: The thickness of the resonant cavity unit (2) in the microcavity structure unit ranges from 0.24 cm to 1.9 cm.

6. The fan-type ventilation and sound insulation device based on the Helmut Holtz resonance cavity according to claim 1, characterized in that: The number of the microcavity structural units ranges from 4 to 8.

7. The fan-type ventilation and sound insulation device based on the Helmut Holtz resonance cavity according to claim 1, characterized in that: The angles of the slots (5) between adjacent resonant cavity units (2), the slot angles between adjacent narrow neck units (3), and the slot angles between the narrow neck unit (3) and the resonant cavity unit (2) are all 2 degrees.

8. The fan-type ventilation and sound insulation device based on the Helmut Holtz resonance cavity according to claim 1, characterized in that: The narrow neck unit (3) has a certain opening angle, and its width gradually increases in the direction away from the main body (1), and the opening angle of each narrow neck unit (3) is the same.

9. The fan-type ventilation and sound insulation device based on the Helmut Holtz resonance cavity according to claim 8, characterized in that: The angle range of the narrow neck unit (3) is 4 degrees to 8 degrees.

10. An acoustic barrier, comprising: a fan-type ventilation and sound insulation device based on a Helmut Holtz resonator according to any one of claims 1 to 9 as a basic unit; substrates of a plurality of fan-type ventilation and sound insulation devices are spliced together; and the fan-type ventilation and sound insulation devices are periodically arranged and distributed in the horizontal and vertical directions.

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