CN115234739A - Hollow pipeline sound insulation device based on generalized Snell's law - Google Patents
Hollow pipeline sound insulation device based on generalized Snell's law Download PDFInfo
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- 238000009413 insulation Methods 0.000 title claims abstract description 73
- 238000005516 engineering process Methods 0.000 claims abstract description 5
- 239000007787 solid Substances 0.000 claims description 25
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- 238000010146 3D printing Methods 0.000 claims description 4
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L55/00—Devices or appurtenances for use in, or in connection with, pipes or pipe systems
- F16L55/02—Energy absorbers; Noise absorbers
- F16L55/033—Noise absorbers
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L55/00—Devices or appurtenances for use in, or in connection with, pipes or pipe systems
- F16L55/02—Energy absorbers; Noise absorbers
- F16L55/033—Noise absorbers
- F16L55/0336—Noise absorbers by means of sound-absorbing materials
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Abstract
The invention discloses a hollow pipeline sound insulation device based on the generalized Snell's law, which comprises sound insulation parts symmetrically arranged on the inner wall of a pipeline, wherein the sound insulation parts are formed by cascading acoustic super-surface units formed by a plurality of cavities with different depth sizes; the super surface unit of acoustics include that inside is the fretwork, the bottom leaves the gap, has the cuboid structure of certain thickness, the position and the phase gradient of super surface unit of every acoustics make the sound wave take place to reflect when passing through the pipeline. The acoustic super-surface unit sample piece is designed by utilizing a super-surface technology based on the generalized Snell's law, and the sound waves are modulated by utilizing the phase gradient, so that the sound waves are abnormally reflected, the energy is limited in the pipeline, and the sound insulation effect is achieved.
Description
Technical Field
The invention relates to the technical field of acoustic low-frequency sound insulation, in particular to a hollow pipeline sound insulation device based on generalized Snell's law.
Background
The existing engineering enterprise pipeline system is complex, and is necessary to control the pipeline noise in order to reduce noise pollution and protect the physical and mental health of residents around the enterprise. The pipeline low-frequency noise reduction has urgent application requirements in practical engineering, and particularly has significance in the field of acoustics when sound insulation with wider working bandwidth is realized in a low-frequency band. Control of pipe noise can be initiated from three aspects: noise sources, propagation paths, reception environments; the methods for reducing noise can be roughly divided into two methods, namely active noise reduction and passive noise reduction. Actively reducing noise by a human hand from a noise source, and generating sound with the same frequency spectrum as the noise but opposite phase through an external sound source to offset the noise; passive noise reduction addresses noise through material and construction techniques from two other aspects. The sound in the pipeline is noisy and the pipeline system is complex, the noise reduction effect is difficult to ensure by using active noise reduction, and the manufacturing cost is higher, so the noise is controlled by a passive noise reduction method.
The existing method for solving the pipeline noise mainly comprises the steps of wrapping a pipeline by using a sound insulation material, or building a sound-absorbing chamber by using a sound absorption material, or connecting a silencer in series between two pipelines. The material is used for wrapping the pipeline to influence the heat dissipation of the pipeline and has a less ideal sound insulation effect on the low-frequency band, and the silencer is high in cost and troublesome to install and maintain. Therefore, new technical means are introduced to explore the pipeline noise reduction.
The acoustic metamaterial has super strong regulation and control capability on sound waves, and can enable the sound waves to be abnormally reflected and refracted, so that special application requirements are met, but certain problems still exist for some common metamaterials, such as: the volume is large, the manufacturing cost is high, and the working bandwidth is narrow.
Disclosure of Invention
The invention provides a hollow pipeline sound insulation device based on the generalized Snell's law; the acoustic super-surface unit can be used for realizing the lightness and thinness of the material, the thickness can reach the sub-wavelength scale, and the acoustic wave is controlled by regulating and controlling the phase of the microstructure; the transportation of the medium in the pipeline can not be influenced; the technical problem can be effectively solved.
The invention is realized by the following technical scheme:
a hollow pipeline sound insulation device based on generalized Snell's law comprises sound insulation parts symmetrically arranged on the inner wall of a pipeline, wherein the sound insulation parts are formed by cascading acoustic super-surface units formed by a plurality of cavities with different depth sizes; the super surface unit of acoustics include that inside is the fretwork, the bottom leaves the gap, has the cuboid structure of certain thickness, the position and the phase gradient of super surface unit of every acoustics make the sound wave take place to reflect when passing through the pipeline.
Further, the acoustic metamaterial unit is made of weak anisotropic acoustic metamaterial, the acoustic metamaterial unit comprises a solid structure and a background fluid, and the equivalent mass density and the bulk modulus of the acoustic metamaterial are distributed in an anisotropic mode.
Furthermore, the sound insulation part is made of a plurality of acoustic super-surface units with different phase gradients, the sound insulation part comprises a solid structure and a background medium, and the depth size and the phase gradient of a cavity of each acoustic super-surface unit are different.
Further, the solid structure of the acoustic super-surface unit has a phase gradient of:
wherein, theta r Is the angle of reflection, theta i For the angle of incidence, λ is the wavelength of the acoustic wave and d φ/dx is the phase gradient.
Furthermore, the solid structure of the acoustic super-surface unit is formed by cascading a plurality of different super-surface units, wherein the middle part of the solid structure is hollow, the depth dimension d of the cavity is different, a w gap is reserved at the bottom of the solid structure, the thickness of the solid structure is t, and the cuboid is formed.
Further, the length of the solid structure of the acoustic super-surface unit is 60 cm, the adjustable region of the cavity depth dimension d is 4 mm to 49 mm, the gap w reserved at the bottom is 1 mm, and the thickness t is 1 mm.
Furthermore, the solid structure of the acoustic super-surface unit is made of ABS or photosensitive resin.
Furthermore, the solid structure of the acoustic super-surface unit is processed and manufactured by adopting a 3D printing technology.
Furthermore, the acoustic super-surface units are cascaded to form the super-surface sound insulation part, and when sound waves enter the acoustic super-surface units attached to the inner wall, the phase of the sound waves changes suddenly at an interface acted by the sound waves, so that reflection is formed.
Advantageous effects
Compared with the traditional prior art, the hollow pipeline sound insulation device based on the generalized Snell's law provided by the invention has the following beneficial effects:
(1) The technical scheme is based on the generalized Snell's law, the acoustic super-surface units are cascaded to form the super-surface sound insulation part, the part occupies about 1/8 of the pipe diameter, sound waves are modulated by utilizing phase gradients, the phases of the sound waves are suddenly changed at the interface of the acoustic super-surface units acting on the sound waves, the sound waves are abnormally reflected, energy is limited in the pipeline, and therefore the sound insulation effect is achieved.
(2) The technical scheme can be used for pipelines with large low-frequency noise, and limits sound energy to the middle of the sample piece arranged on the inner wall of the pipeline, so that the aim of low-frequency sound insulation of the pipeline is fulfilled. This scheme has compromise the characteristics at low frequency channel sound insulation bandwidth broad, prints quick forming technology by 3D and makes, is convenient for be applied to pipe-line system, does not influence its inside medium circulation.
Drawings
FIG. 1 is a diagram of the basic mechanism of the present invention.
Fig. 2 is a schematic view showing the sound-proof member of the present invention installed inside a hollow duct.
Fig. 3 is a schematic view of the overall structure of the present invention.
Fig. 4 is a schematic solid structure diagram of an acoustic super-surface unit according to the present invention.
FIG. 5 is a phase diagram of an acoustic super-surface unit according to the present invention.
FIG. 6 is a graph of acoustic energy at 800Hz in accordance with the present invention.
Fig. 7 is a graph of acoustic transmission curves for the theory and the entity of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.
Example 1:
a hollow pipeline sound insulation device based on generalized Snell's law comprises sound insulation parts symmetrically arranged on the inner wall of a pipeline, wherein the sound insulation parts are formed by cascading acoustic super-surface units formed by a plurality of cavities with different depth sizes; the super surface unit of acoustics include that inside is the fretwork, the bottom leaves the gap, has the cuboid structure of certain thickness, the super surface unit of every acoustics position and phase gradient make the sound wave take place to reflect when passing through the pipeline.
The key of sound wave reflection lies in the phase change, and sound waves are abnormally reflected through the phase gradient change of the sound insulation part, so that sound energy is gathered in the pipeline. The position of each acoustic super-surface unit corresponds to the phase gradient of the sound insulation device, and all the acoustic super-surface units are cascaded to form the phase gradient required by sound wave reflection, so that abnormal reflection of the sound wave is realized.
As shown in fig. 1, this is the sound insulation mechanism of the present solution. When the sound waves are incident to the sound insulation part, the sound waves are reflected according to the designed reflection path, and the sound energy is gathered inside the pipeline, so that the aim of low-frequency sound insulation is fulfilled. The sound insulation device for the hollow pipeline realizes the phase change by controlling the depth size of the cavity, and meanwhile, the hollow design does not influence the circulation of media in the pipeline.
In particular embodiments, the acoustic super-surface units are phase-diverse. The acoustic metamaterial unit is made of weak anisotropic acoustic metamaterial and comprises a solid structure and background fluid, and the equivalent mass density and the bulk modulus of the acoustic metamaterial are in anisotropic distribution. Namely: the sound insulation part is made of a plurality of acoustic super-surface units with different phase gradients and comprises a solid structure and a background medium, the depth sizes of cavities of the acoustic super-surface units are different, and the depth sizes of the cavities of the acoustic super-surface units are different, so that the phase gradients of the acoustic super-surface units are changed.
The invention applies the generalized Snell's law to design the phase gradient of the super surface to control the reflection direction of the sound wave, so that the sound energy is gathered in the pipeline, and the effect of low-frequency sound insulation is achieved. The volume of the designed acoustic super-surface unit is small, occupies about 1/8 of the volume of an experimental pipeline, and is manufactured by using a 3D printing technology, so that the cost is low.
According to the generalized Snell's law, the phase gradient of the solid structure of the acoustic super-surface unit satisfies the following relation:
wherein, theta r Is angle of reflection, theta i And the angle of incidence or reflection of the sound wave is considered to be an included angle with the normal line of the super surface.
In the design, some parameters (mass density or bulk modulus, etc.) of the material are not changed, and only the phase distribution of the material is changed to obtain a more ideal reflection effect, so that the process of designing the device becomes simple and easy.
According to the phase distribution of the acoustic super-surface units, the acoustic super-surface units formed by the cavities with different depth sizes are cascaded, and the designed sound insulation part is obtained after cascading, namely the arrangement of the super-surface units of the sound insulation part is controlled by phase gradient.
In order to obtain the sound insulation part with better sound insulation capacity and wider bandwidth in the low-frequency band, the acoustic super-surface units are cascaded, the cascade order is arranged according to the phase distribution of the design units, the phase distribution is determined by the cavity depth size of the acoustic super-surface units, as shown in fig. 2, the length of the sound insulation part is 60 cm, the length of a single acoustic super-surface unit shown in fig. 3 is 5 cm, the opening gap w is 1 mm, the thickness t is 1 mm, and the adjustment range of the cavity depth size d is 4 mm to 49 mm.
The phase of the acoustic super-surface unit structure directly influences the reflection condition of sound waves when the sound waves pass through the sound insulation part, and the change of the phase is related to the depth dimension d parameter of a cavity in the acoustic super-surface unit structure. The scheme can realize the sound insulation effect with the bandwidth of 500Hz to 1600Hz through cascading designed acoustic super-surface units, as shown in figure 5, the sound energy can not be transmitted to the other side of the pipeline through a sound insulation part theoretically at 800Hz, and figure 7 shows that the designed device has better sound insulation quantity from 500Hz to 1600Hz theoretically and experimentally.
The super surface unit of acoustics adopts common ABS or photosensitive resin as raw and other materials, processes through 3D printing technique and makes, the accurate shaping of being convenient for.
The sound insulation of the designed frequency band can be realized by applying the method in the scheme, as shown in fig. 2, the sound insulation parts are symmetrically arranged on the inner wall of the pipeline, when sound waves pass through the sound insulation parts, abnormal reflection can occur due to the change of the phase, and the sound energy is limited in the pipeline, so that the sound insulation purpose is achieved. Fig. 3 is an example to illustrate the design process of the low-frequency sound-proof device.
Firstly, the functional effects of the hollow pipeline sound insulation device are clear: under the condition of not influencing the medium circulation in the pipeline, the sound insulation device has better sound insulation and working bandwidth in a low-frequency band. In order to achieve the effect, according to the generalized Snell's law, the sound insulation device has a phase jump when sound waves act, so that the sound waves are abnormally reflected. By designing the super-surface units with different frequency points, considering the frequency bands adjacent to the designed frequency points during design, and cascading the super-surface units and the frequency bands, the sound insulation device with ideal sound insulation effect in the range of 500Hz to 1600Hz can be obtained.
In order to verify the implementation effect of the sound insulation device, COMSOL MUTIPHYSICS simulation software is applied to the implementation case to simulate the device, and the device is verified through experiments to obtain a sound transmission curve chart shown in figure 7, which shows that the designed sound insulation device has a good sound insulation effect in a range from 500Hz to 1600Hz, and simultaneously shows that a designed sample piece has the advantage of broadband operation in low frequency. The simulation result is better matched with the trend of the experimental result, and the correctness of the embodiment is verified.
The material object experiment result is consistent with the trend of the simulation calculation result, and the designed hollow pipeline sound insulation device has better sound insulation effect within the frequency band range of 500Hz to 1600 Hz.
The specific processing and preparation process of the hollow pipeline sound insulation device based on the generalized Snell's law is as follows:
(1) And deducing and calculating the phase distribution of the acoustic super-surface units based on the generalized Snell's law to obtain phase parameters of a required reflection angle, and cascading the designed acoustic super-surface units to obtain device parameters, structural parameters and geometric model distribution for a target area.
(2) And establishing a three-dimensional entity model by using the obtained structural parameters and the geometric model in SOLIDWORKS software, exporting the file type which can be used for a 3D printer, and processing the file type by the 3D printer to obtain a finished product.
(3) And carrying out subsequent treatment on the printed finished product of the sound insulation device, wherein the subsequent treatment mainly comprises standing, curing, polishing, cascading and the like.
(4) In order to verify the functional correctness of the hollow pipeline sound-insulating device, a numerical simulation and experimental verification comparison mode can be carried out by sampling, and the preparation is finished when the trend of the obtained experimental data is matched with that of the simulation data, namely when the sound-insulating effect is better from 500Hz to 1600 Hz.
Compared with the prior art, the invention has the advantages that:
(1) The sound insulation device is hollow and is arranged on the inner wall of the pipeline, so that the circulation of internal media is not influenced;
(2) The device has better sound insulation effect in the frequency range of 500Hz to 1600 Hz;
(3) The device does not need to adopt a complex active electronic system, has a small volume of a super-surface structure, and is easy to use in a pipeline;
(4) The sound insulation device can realize a flow preparation process by the preparation method without using a complex theoretical mechanism;
(5) The sample preparation of the invention can adopt common solid structure materials and has the characteristics of low manufacturing cost and good practicability.
Claims (9)
1. The utility model provides a cavity type pipeline sound arrester based on generalized snell's law which characterized in that: the sound insulation component is formed by cascading acoustic super-surface units formed by a plurality of cavities with different depth sizes; the super surface unit of acoustics include that inside is the fretwork, the bottom leaves the gap, has the cuboid structure of certain thickness, the position and the phase gradient of super surface unit of every acoustics make the sound wave take place to reflect when passing through the pipeline.
2. The hollow pipeline sound insulation device based on the generalized Snell's law according to claim 1, wherein: the acoustic metamaterial unit is made of weak anisotropic acoustic metamaterial and comprises a solid structure and background fluid, and the equivalent mass density and the bulk modulus of the acoustic metamaterial are in anisotropic distribution.
3. The hollow type pipe sound insulation device based on the generalized Snell's law according to claim 1 or 2, wherein: the sound insulation part is made of a plurality of acoustic super-surface units with different phase gradients, and comprises a solid structure and a background medium, wherein the cavity depth size and the phase gradients of the acoustic super-surface units are different.
4. The hollow pipeline sound insulation device based on the generalized Snell's law according to claim 3, wherein: the solid structure of the acoustic super-surface unit has the phase gradient as follows:
wherein, theta r Is angle of reflection, theta i For the angle of incidence, λ is the wavelength of the acoustic wave and d φ/dx is the phase gradient.
5. The hollow pipeline sound insulation device based on the generalized Snell's law according to claim 2 or 4, wherein: the solid structure of the acoustic super-surface unit is formed by cascading a plurality of different super-surface units, wherein the middle of the solid structure is hollow, the depth dimension d of a cavity is different, a w gap is reserved at the bottom of the solid structure, and the thickness of the solid structure is t.
6. The hollow pipeline sound insulation device based on the generalized Snell's law according to claim 5, wherein: the length of the solid structure of the acoustic super-surface unit is 60 cm, the adjustable area of the depth dimension d of the cavity is 4 mm to 49 mm, the gap w reserved at the bottom is 1 mm, and the thickness t is 1 mm.
7. A hollow pipeline sound insulation device based on generalized Snell's law according to any one of claims 1, 2, 4 and 6, wherein: the solid structure of the acoustic super-surface unit is made of ABS or photosensitive resin as raw materials.
8. The hollow pipeline sound insulation device based on the generalized Snell's law according to claim 7, wherein: the solid structure of the acoustic super-surface unit is processed and manufactured by adopting a 3D printing technology.
9. The hollow pipeline sound insulation device based on the generalized Snell's law according to claim 7, wherein: the acoustic super-surface units are cascaded to form a super-surface sound insulation part, and when sound waves enter the acoustic super-surface units attached to the inner wall, the phases of the sound waves are suddenly changed at an interface acted with the sound waves to form reflection.
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| CN2022105314531 | 2022-05-16 | ||
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4296831A (en) * | 1979-05-23 | 1981-10-27 | Coal Industry (Patents) Limited | Acoustic liner for attenuating noise |
| CN105845122A (en) * | 2016-03-22 | 2016-08-10 | 南京大学 | Ultrathin bi-directional sound obstruction channel |
| CN105895074A (en) * | 2016-04-11 | 2016-08-24 | 南京大学 | Acoustic unidirectional hyper surface |
| EP3093391A1 (en) * | 2015-05-11 | 2016-11-16 | 4Silence B. V. | Sound-proofing utility, especially a sound-attenuating unit |
| US20170138042A1 (en) * | 2014-07-22 | 2017-05-18 | Korea Advanced Institute Of Science And Technology | Wall And Floor Structure For Reducing Inter-Floor Noise |
| CN208565863U (en) * | 2018-07-05 | 2019-03-01 | 青岛海尔中央空调有限公司 | A kind of pipeline silencer and air-conditioning |
| US20190115002A1 (en) * | 2017-10-16 | 2019-04-18 | The Hong Kong University Of Science And Technology | Sound absorber with stair-stepping structure |
| CN111933106A (en) * | 2020-07-15 | 2020-11-13 | 广东工业大学 | Sound wave reflection regulation and control device based on ultrasonic surface |
-
2022
- 2022-07-19 CN CN202210852604.3A patent/CN115234739A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4296831A (en) * | 1979-05-23 | 1981-10-27 | Coal Industry (Patents) Limited | Acoustic liner for attenuating noise |
| US20170138042A1 (en) * | 2014-07-22 | 2017-05-18 | Korea Advanced Institute Of Science And Technology | Wall And Floor Structure For Reducing Inter-Floor Noise |
| EP3093391A1 (en) * | 2015-05-11 | 2016-11-16 | 4Silence B. V. | Sound-proofing utility, especially a sound-attenuating unit |
| CN105845122A (en) * | 2016-03-22 | 2016-08-10 | 南京大学 | Ultrathin bi-directional sound obstruction channel |
| CN105895074A (en) * | 2016-04-11 | 2016-08-24 | 南京大学 | Acoustic unidirectional hyper surface |
| US20190115002A1 (en) * | 2017-10-16 | 2019-04-18 | The Hong Kong University Of Science And Technology | Sound absorber with stair-stepping structure |
| CN208565863U (en) * | 2018-07-05 | 2019-03-01 | 青岛海尔中央空调有限公司 | A kind of pipeline silencer and air-conditioning |
| CN111933106A (en) * | 2020-07-15 | 2020-11-13 | 广东工业大学 | Sound wave reflection regulation and control device based on ultrasonic surface |
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