WO2019182213A1 - Dispositif d'absorption de son - Google Patents

Dispositif d'absorption de son Download PDF

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Publication number
WO2019182213A1
WO2019182213A1 PCT/KR2018/011196 KR2018011196W WO2019182213A1 WO 2019182213 A1 WO2019182213 A1 WO 2019182213A1 KR 2018011196 W KR2018011196 W KR 2018011196W WO 2019182213 A1 WO2019182213 A1 WO 2019182213A1
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Prior art keywords
sound
sound absorbing
helmholtz resonators
helmholtz
hole
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PCT/KR2018/011196
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English (en)
Korean (ko)
Inventor
전원주
유현빈
Original Assignee
한국과학기술원
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Priority claimed from KR1020180031540A external-priority patent/KR20190109893A/ko
Priority claimed from KR1020180109256A external-priority patent/KR102116466B1/ko
Application filed by 한국과학기술원 filed Critical 한국과학기술원
Publication of WO2019182213A1 publication Critical patent/WO2019182213A1/fr

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    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/172—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using resonance effects

Definitions

  • the present invention relates to a sound absorbing device, and more particularly, to an ultra-thin sound absorbing device capable of absorbing one or more frequencies at a high sound absorption rate.
  • Efficiently reducing ambient noise is an important consideration in everyday life or in industrial settings. Sound absorption methods used in many industrial sites to reduce noise generated in various mechanical facilities, etc. can be divided into porous type, resonance type and plate type sound absorbing types.
  • Porous sound absorption method improves sound absorption rate at specific frequency and broadband frequency by adopting appropriate material with high sound absorption performance.
  • Resonance type and plate type sound absorption method partially absorb sound absorption rate at specific frequency by modifying internal structure of sound absorbing material. It's a way to improve.
  • One aspect of the present invention is to provide a sound absorbing device that is thin and absorbs noise of one or more frequencies at a high sound absorption rate.
  • Sound absorbing device a plurality of Helmholtz resonators arranged on a plane, each of the plurality of Helmholtz resonators, the neck portion of a predetermined thickness through which the hole in the thickness direction; And a chamber part connected to the neck and provided with an inner space in which sound waves are communicated through the hole, and having a different resonance frequency from at least one of the adjacent Helmholtz resonators.
  • a partition wall may be provided in the inner space of at least one of the plurality of Helmholtz resonators to guide the traveling direction of the sound waves.
  • Each of the plurality of Helmholtz resonators may have at least one of a size of the adjacent Helmholtz resonator and the hole, a thickness of the neck portion, and a volume of the inner space.
  • the plurality of Helmholtz resonators may have a square pillar shape of the same size, and four Helmholtz resonators may be arranged in a lattice form to form one flaw cell, and the plurality of sound absorbing cells may be arranged in a lattice form on the plane.
  • the size of the holes may be differently formed between the Helmholtz resonators in which the surfaces of the four Helmholtz resonators contact each other.
  • the four Helmholtz resonators may be formed to have different sizes of the holes.
  • the four Helmholtz resonators may have the same volume as the volume of the inner space and the thickness of the neck.
  • the sound absorption cell may have two or more sound absorption frequencies.
  • the partition wall is formed with an opening through which the sound wave can pass, and in the Helmholtz resonator provided with the partition wall, a path of the sound wave traveling through the inner space by the inner surface of the chamber part and the partition wall may be defined.
  • the partition may be guided so that the traveling direction of the sound wave is changed at least once.
  • the plurality of Helmholtz resonators are eight Helmholtz resonators, some of which are different from each other in the length of the path of the sound waves, the eight Helmholtz resonators adjacent to each other to form a single sound-absorbing cell of the square column shape,
  • the sound absorbing cells may be arranged in a lattice form on the plane.
  • the eight Helmholtz resonators may have the shape of a polygonal column having the same height, and the holes may have different sizes.
  • Two Helmholtz resonators of each of the eight Helmholtz resonators may be arranged adjacently to form four square pillars of the same size, and the four square pillar shapes may be adjacent to form the sound absorbing cell.
  • the eight Helmholtz resonators may have a length of at least three different paths of the sound wave.
  • the sound absorption cell may have four or more sound absorption frequencies.
  • the partition wall extends in the thickness direction, and partitions the internal space in the same area on the plane, and the path of the sound wave may be connected through the opening.
  • the plane may be perpendicular to the direction of incident sound waves, and the holes may be arranged to face the sound waves.
  • each of the plurality of Helmholtz resonators may be smaller than the wavelength of the sound wave.
  • the sound waves may have different phases reflected from adjacent Helmholtz resonators and may cause destructive interference.
  • noise can be absorbed at a high sound absorption rate.
  • the partition structure which extends the path of a sound wave is formed in a Helmholtz resonator, and it can exhibit a high flaw rate while making thickness very thin.
  • FIG. 1 is a perspective view of a scratch device according to an embodiment of the present invention.
  • FIG. 2 is a perspective view of a sound absorbing cell constituting the sound absorbing device according to the first embodiment of the present invention.
  • FIG. 3 is a perspective view of the Helmholtz resonator constituting the sound absorbing cell of FIG.
  • FIG. 4 is a front view of a sound absorbing cell constituting the sound absorbing device according to the first embodiment of the present invention.
  • FIG. 5 is a graph showing the sound absorption performance of the sound absorbing device according to the first embodiment of the present invention.
  • FIG. 6 is a front view of a sound absorbing cell constituting the sound absorbing device according to the second embodiment of the present invention.
  • 7 and 8 are graphs showing the scratching performance of the sound absorbing device according to the second embodiment of the present invention.
  • FIG. 9 is a perspective view of a sound absorbing cell constituting the sound absorbing device according to the third embodiment of the present invention.
  • FIG. 10 is a perspective view illustrating a Helmholtz resonator constituting the sound absorbing cell of FIG. 9.
  • FIG. 11 is a front view of a sound absorbing cell constituting the sound absorbing device according to the third embodiment of the present invention.
  • FIG. 12 is a graph showing sound absorption performance of the sound absorbing device according to the third embodiment of the present invention.
  • FIG. 14 is a front view of a sound absorbing cell constituting the sound absorbing device according to the fourth embodiment of the present invention.
  • 15 to 17 are perspective views illustrating a Helmholtz resonator constituting the sound absorbing cell of FIG. 14.
  • FIG. 18 is a graph showing sound absorption performance of the sound absorbing device according to the fourth embodiment of the present invention.
  • FIG. 19 is a perspective view of a sound absorbing cell constituting the sound absorbing device according to the fifth embodiment of the present invention.
  • 20 to 23 are perspective views illustrating a Helmholtz resonator constituting the sound absorbing cell of FIG. 19.
  • FIG. 24 is a graph showing sound absorption performance of the sound absorbing device according to the fifth embodiment of the present invention.
  • FIG. 25 is a perspective view of a sound absorbing cell constituting the sound absorbing device according to the sixth embodiment of the present invention.
  • FIG. 26 is a perspective view illustrating a Helmholtz resonator constituting the sound absorbing cell of FIG. 25.
  • FIG. 27 is a front view illustrating the Helmholtz resonator of FIG. 26.
  • FIG. 1 is a perspective view of a scratch device according to an embodiment of the present invention.
  • a sound absorbing device 100 includes a plurality of sound absorbing cells C arranged two-dimensionally on a plane, and has a thin panel or board. ) Form.
  • the sound absorbing cell C may be a basic unit, and the plurality of sound absorbing cells C may be continuously arranged adjacent to each other in the x-axis and y-axis directions with reference to FIG. 1.
  • the plurality of sound absorption cells C may be arranged in a lattice form on an xy plane perpendicular to the incident sound wave.
  • the sound absorbing device 100 of the present invention is not limited to being composed of a plurality of sound absorbing cells C, and the sound absorbing device 100 is formed of only one sound absorbing cell C instead of the plurality of sound absorbing cells C. It may be configured.
  • the sound absorbing cell C may be composed of a plurality of Helmholtz resonators arranged on a plane.
  • Helmholtz Resonator is a device that absorbs sound by resonating air at a specific frequency. It has a closed shape with a neck and is absorbed by frictional heat loss when air enters and exits through a small hole through the neck.
  • the Helmholtz resonator may include a neck having a predetermined thickness through which a hole is passed, and a chamber part connected to the neck to provide an inner space, and the neck part and the chamber part may be integrally formed.
  • the hole may be disposed toward the sound source for generating sound waves, the sound waves may pass through the hole formed in the neck of the Helmholtz resonator to proceed to the interior space of the chamber.
  • Helmholtz resonators are well known to those skilled in the art, and thus will not be described in more detail.
  • the plurality of Helmholtz resonators constituting the sound absorbing cell (C) may be arranged adjacently so that there is no space therebetween, as shown in Figure 1, the sound absorbing cell (C) in the form of a square column Can be formed.
  • each of the plurality of Helmholtz resonators arranged on the plane may be arranged to have a different resonance frequency from the adjacent Helmholtz resonators.
  • the resonance frequency is determined by the following equation (f is the resonance frequency, v is the speed of sound waves, A is the area of the hole, V is the volume of the inner space, and l is the length of the hole).
  • each of the plurality of Helmholtz resonators includes at least one size and a neck of the adjacent Helmholtz resonator and the hole 125. At least one of the thickness (length in the z-axis direction) of 122 (see FIG. 3) and the volume of the space 126 (see FIG. 3) may be arranged differently.
  • the front and the rear define a direction closer to the sound source that generates sound waves, and the rear and rearward directions.
  • a detailed structure of the sound absorbing device 100 and various sound absorbing effects thereof will be described.
  • the structure of the sound absorbing cell constituting the sound absorbing device 100 will be described mainly, and the plurality of sound absorbing cells C are two-dimensionally arranged on a plane in all embodiments.
  • FIG. 2 is a perspective view of a sound absorbing cell constituting the sound absorbing device according to the first embodiment of the present invention.
  • the plurality of Helmholtz resonators 120 constituting the sound absorbing cell C1 may be arranged in a lattice form on a plane.
  • the plurality of Helmholtz resonators 120 may be arranged in a lattice form on a plane perpendicular to the incident sound wave S so that the reflectance may be zero at a specific frequency of the incident sound wave S.
  • the hole 125 of the Helmholtz resonator 120 may be arranged toward the incident sound wave S. That is, in FIG.
  • the plurality of Helmholtz resonators 120 are arranged in the x-axis and y-axis directions on the xy plane perpendicular to the incident sound wave S.
  • the hole 125 of the resonator 120 may face the z-axis direction.
  • the sizes of the holes 125 may be differently disposed between the Helmholtz resonators adjacent in at least one direction among the plurality of Helmholtz resonators 120 arranged on the plane.
  • the sizes of the holes 125 may be formed differently between Helmholtz resonators adjacent in two axes (x-axis, y-axis) perpendicular to each other on a plane (xy plane) perpendicular to the incident sound wave S. .
  • the sound absorbing device 100 may select and absorb a specific frequency by adjusting the size of the holes 125 of the Helmholtz resonators 120 adjacent to each other, and increase one or more specific frequencies.
  • the sound absorption can be defected, the detailed structure of the sound absorption cell C1 will be described below.
  • a plurality of sound absorbing cells C1 composed of four Helmholtz resonators 120 have a lattice shape, for example, FIG. 1. It may be configured to have a structure arranged adjacent to the x-axis and y-axis directions in the. That is, the sound absorbing device 100 is a form in which the sound absorbing cells C1 are continuously arranged on a plane, with the fault cell C1 composed of four Helmholtz resonators 120 as a basic unit.
  • the Helmholtz resonator 120 may have a size smaller than the wavelength of the sound wave S (subwavelength scale).
  • the length of one side of the Helmholtz resonator 120 that is, the thickness of the Helmholtz resonator 120 (H, see FIG. 2) and the length and width of the horizontal and vertical (D / 2, see FIG. 2) is a sound wave (S) It may be smaller than the wavelength of.
  • S sound wave
  • a high scratch effect can be exhibited in a small space.
  • by reducing the thickness H of the Helmholtz resonator 120 it is possible to function as a meta-surface by attaching a thin-shaped panel-shaped flaw device 100 to the wall.
  • FIG. 3 is a perspective view of the Helmholtz resonator constituting the sound absorbing cell of FIG.
  • the Helmholtz resonator 120 has a neck portion 122 having a predetermined thickness through which the hole 125 penetrates, and a space 126 continuously connected to the rear of the neck portion 122 to communicate with the hole 125. It may include the chamber portion 124 is provided. Accordingly, sound waves incident from the outside may enter the internal space through the hole 125.
  • the Helmholtz resonator 120 may have a polygonal column shape, and a cross section of the Helmholtz resonator 120 in a direction parallel to the plane where the Helmholtz resonator 120 is arranged may have a polygonal shape.
  • the Helmholtz resonator 120 may have a rectangular parallelepiped shape.
  • the neck 122 and the chamber 124 may be integrally formed to form a rectangular parallelepiped.
  • the sound absorbing cell C1 may be formed by arranging four Helmholtz resonators in contact with each other.
  • the shape of the Helmholtz resonator 120 is not limited to the shape of a rectangular parallelepiped, but may also be in the form of an oblique column.
  • the structure of the Helmholtz resonator 120 having a rectangular parallelepiped shape will be described.
  • the neck 122 and the space 126 through which the hole 125 of a predetermined length (or thickness) 1 is pierced are described.
  • the chamber unit 124 having a) may be integrally formed.
  • the hole 125 has a circular cross section of a predetermined size, extends to connect the space 126 inside and outside the Helmholtz resonator 120 with each other, and may have a predetermined diameter 2r.
  • the space 126 is connected to the rear end of the hole 125 so as to communicate with the hole 125, and the chamber 124 may have a predetermined thickness, so that the space 126 corresponds to the shape of the chamber 124. It may have a rectangular parallelepiped shape.
  • the space 126 may have a rectangular parallelepiped shape of horizontal (x-axis length), vertical (y-axis length), and depth (z-axis length), respectively, g, a, and b.
  • the shape of the space 126 is not limited to the rectangular parallelepiped, and may be formed in various shapes having a predetermined volume.
  • the chamber portion 124 is a rectangular parallelepiped shape
  • the neck portion 122 may be formed in a columnar shape, for example, a cylinder protruding on one surface of the rectangular parallelepiped. .
  • the Helmholtz resonator 120 may have a square pillar shape. Accordingly, when the sound absorbing device 100 is viewed from the front (z-axis direction), the sound absorbing cell C1 is also square, and the sound absorbing device 100 may be formed in a lattice form in which square sound absorbing cells C1 are continuously arranged. .
  • the cross section of the Helmholtz resonator 120 may be a square having a length D / 2
  • the cross section of the flaw cell C1 may be a square having a length D of one side.
  • the sound absorbing device 100 forms a different size of the hole 125 of the Helmholtz resonator 120 and the Helmholtz resonator 120 having a different size of the hole 125 on the x-axis or By arranging in the y-axis direction, it is possible to exhibit a high defect rate for one or more specific frequencies.
  • the arrangement of the Helmholtz resonators 120 having different sizes of the holes 125 and the relationship between the holes 125 and the defect frequencies are described. It explains in detail.
  • FIG. 4 is a front view of a sound absorbing cell constituting the sound absorbing device according to the first embodiment of the present invention
  • Figure 5 is a graph showing the sound absorption performance of the sound absorbing device according to the first embodiment of the present invention.
  • the Helmholtz resonators constituting the sound-absorbing cell (C1) in FIG. 4 is shown with reference numeral 120, four Helmholtz resonators may be referred to as the first to fourth Helmholtz resonators, respectively, as needed in the following description; , 120-1 ⁇ 120-4.
  • the holes 125 are also divided by the same reference numerals, and may be referred to as needed in the following description. This division method is equally applicable to the description of other embodiments.
  • two types of Helmholtz resonators 120-1 and 120-2 having different sizes of holes 125 are arranged to form one sound absorbing cell ( C1) may be configured. That is, the size of the holes 125-1 and 125-2 may be the same between the Helmholtz resonators arranged in the diagonal direction when viewed from the front among the four Helmholtz resonators constituting one sound absorbing cell C1. That is, the size of the holes may be arranged differently between the Helmholtz resonators in contact with each other.
  • the sound waves S incident toward the sound absorbing device 100 are Helmholtz resonators, that is, holes having different sizes in the x-axis or y-axis direction.
  • the phases reflected by the Helmholtz resonators can be reversed at certain frequencies.
  • destructive interference may be generated, whereby a sound absorption effect may be exerted.
  • the diameters of the holes of the first Helmholtz resonator 120-1 and the second Helmholtz resonator 120-2 which are adjacent in the x-axis or y-axis direction and have different sizes of holes are respectively
  • a perfect sound absorption effect can be exhibited at a specific frequency when the following Equation 1 is satisfied.
  • r 1 is the radius of the hole 125-1 of the first Helmholtz resonator 120-1
  • r 2 is the radius of the hole 125-2 of the second Helmholtz resonator 120-2.
  • Equation 2 the sound absorption frequency f peak at which perfect sound absorption is satisfied satisfies Equation 2 below.
  • a 19mm
  • b 25mm
  • g 19mm
  • l 14mm
  • D 41mm
  • H 40mm
  • r 1 2.85mm
  • FIG. 5 is a graph showing a reflection coefficient (R MS ) and a sound absorption coefficient (a MS ) of a flaw device 100 designed as described above to absorb sound waves having a frequency of 700 Hz through a numerical analysis model. It can be seen that a high sound absorption effect of more than% is exhibited.
  • R MS reflection coefficient
  • a MS sound absorption coefficient
  • a perfect sound absorbing effect can be exhibited with respect to one specific frequency.
  • a high sound absorbing effect can be achieved with respect to two or more frequencies.
  • FIGS. 7 and 8 are graphs showing the flaw performance of the sound absorbing device according to the second embodiment of the present invention.
  • the four types of Helmholtz resonators 220-1, 220-2, 220-3, and 220-4 with different sizes of the holes 225 are provided.
  • one sound absorbing cell (C2) By arranging one sound absorbing cell (C2) can be configured. That is, the four Helmholtz resonators 220-1, 220-2, 220-3, and 220-4, which constitute one sound absorbing cell C2, are holes 225-1, 225-2, 225-3, and 225, respectively. -4) may be formed differently in size.
  • the sound waves S incident toward the sound absorbing device 100 are respectively reflected in a phase at which the phases reflected between adjacent Helmholtz resonators in the x-axis direction. They may be opposite to each other or destructive interference may occur.
  • sound waves having one target frequency are adjusted by adjusting the diameters of the holes of the two types of Helmholtz resonators 220-1 and 220-2 arranged on the upper portion of the sound absorbing cell C2. It can completely absorb the sound, and by adjusting the diameter of the holes of the two other types of Helmholtz resonators 220-3, 220-4 arranged in the lower portion of the sound absorbing cell (C2) it can completely absorb sound waves having different target frequencies. That is, by adjusting the sizes of the holes of the four Helmholtz resonators 220-1, 220-2, 220-3, and 220-4, which constitute the sound absorbing cell C2, two different frequencies can be completely absorbed. have.
  • the Helmholtz resonators located above the sound absorbing cell C2 and adjacent in the x-axis direction are referred to as a first Helmholtz resonator 220-1 and a second Helmholtz resonator 220-2, respectively.
  • the diameters of the holes of the first Helmholtz resonator 220-1 and the second Helmholtz resonator 220-2 are 2r 1 and 2r 2 , respectively, the target frequencies satisfying the above-described equations 1 and 2 can be obtained.
  • the diameter of the hole, ie r 1 , r 2 can be obtained.
  • the values of r 1 , r 2 , r 3 and r 4 can be optimized. More specifically, the diameter of the hole of each Helmholtz resonator can be completely absorbed by the optimization algorithm so that the sound absorption coefficient of the sound absorption cell calculated for the two target frequencies is maximized. At this time, the initial value of the diameter of the hole can be set to the diameter of the hole of the four Helmholtz resonators obtained through the above equations (1) and (2).
  • the objective function used in the optimization algorithm may be set to maximize the sound absorption coefficient of the sound absorption cell, or may be set to minimize the difference between the acoustic impedance of the outer medium and the effective acoustic impedance of the sound absorption cell.
  • the sequential quadratic programming (SQP) method may be used for the optimization algorithm, but the present invention is not limited thereto, and various well-known methods may be used.
  • FIG. 7 is a graph of calculating the reflection coefficient (R MS ) and the absorption coefficient (a MS ) through a numerical analysis model of a flaw device 100 designed to absorb sound waves of two frequencies, 400 Hz and 600 Hz. It can be seen that the high sound absorption effect of more than 95% is exhibited at each of the two desired frequencies 400Hz and 600Hz.
  • the sound absorption may be efficiently performed at two or more frequencies or a wide frequency band according to the sound absorption frequency.
  • the two desired frequencies for sound absorption are 400Hz and 500Hz
  • FIG. 8 is a graph of calculating the reflection coefficient (R MS ) and the absorption coefficient (a MS ) through a numerical analysis model of a flaw device 100 designed to absorb sound waves of two frequencies, 400 Hz and 500 Hz. It can be seen that a high sound absorption effect of more than 95% is exhibited at 400Hz and 500Hz respectively.
  • the size of the holes of the four Helmholtz resonators 220-1, 220-2, 220-3, and 220-4 constituting the intake cell C2 can be adjusted differently so as to be effective in two or more frequencies or a wide frequency band.
  • the sound absorbing device 100 of the present invention can be designed to absorb sound.
  • the present invention is not limited thereto, and a sound absorbing device having the same effect by adjusting at least one of the size of the hole, the thickness of the neck, and the volume of the inner space, which are factors influencing the resonance frequency of the Helmholtz resonator, is provided. Can be implemented.
  • the sound absorption apparatus 100 which exhibits the same effect can be comprised.
  • At least one inner space of the plurality of Helmholtz resonators constituting the sound absorbing cell C may be provided with a partition wall for guiding a traveling direction of sound waves entering the inner space. have. Accordingly, it is possible to extend the path of the sound waves, so that the thickness of the sound absorbing device can be implemented to be thin.
  • the partition is provided in the following description. In the following description, features that are common to the first and second embodiments described above will be omitted and description will be given focusing on differences.
  • FIG. 9 is a perspective view of a sound absorbing cell constituting the sound absorbing device according to the third embodiment of the present invention
  • FIG. 10 is a perspective view showing a Helmholtz resonator constituting the sound absorbing cell of FIG. 9, and
  • FIG. It is a front view of the sound absorption cell which comprises the sound absorption apparatus which concerns on 3rd Example.
  • the path of sound waves traveling through the inner space of the Helmholtz resonator is shown by a thick solid arrow, and the partition wall is darkly shown. This illustrated method was similarly applied to the drawings of the other embodiments.
  • the sound absorbing device 100 has a sound absorbing cell C3 based on a sound absorbing cell C3 including four Helmholtz resonators 320. It is a form arrange
  • the square column-shaped sound absorbing cell C3 may be configured with four Helmholtz resonators 320 having a square pillar shape.
  • the inner space may have a square pillar shape and may be horizontal (x-axis direction). Length), length (y-axis length), and thickness (z-axis length) may be 2a, 2a, and b, respectively.
  • the shape of the inner space is not limited to the square pillar, and may be formed in various shapes having a predetermined volume.
  • the Helmholtz resonator 320 constituting the sound absorbing cell C3 is continuously connected to the neck 122 having a predetermined thickness through which the hole 325 penetrates and the rear of the neck 122. It includes a chamber portion 324 is provided with an internal space in communication with the outside through the sound source. Accordingly, sound waves incident from the outside may enter the internal space through the hole 325.
  • At least one of the plurality of Helmholtz resonators 320 may include a partition wall in an inner space.
  • a partition wall 327 may be provided in an inner space of each of the four Helmholtz resonators 320 constituting the sound absorbing cell C3.
  • the partition wall 327 partitions the inner space of the Helmholtz resonator 320 and may exert an effect of extending the path of sound waves traveling in the inner space. According to the exemplary embodiment of the present invention, the traveling direction of the sound wave may be guided at least once by the partition wall 327.
  • the partition wall 327 partitions the inner space of the Helmholtz resonator 320 in the same volume, and may partition the inner space in the same area based on the xy plane, and an opening through which sound waves can pass. 329 may be formed.
  • the inner space may also have a square pillar shape.
  • the partition wall 327 is formed in a cross shape in which two planes intersect to form an inner space of the same volume. It can be divided into four square columnar spaces.
  • an opening portion 329 may be formed at an end side of the partition wall 327. Accordingly, the path of the sound wave may be bent and changed several times by the partition wall 327 and the opening part 329. .
  • the sound waves pass through the four spaces divided by the partition wall 327 sequentially through the opening portion 329, so that the path of the sound waves is lower than that without the partition wall 327. Can be extended.
  • the path of the sound waves traveling through the inner space by the inner surface of the chamber part 324 and the partition wall 327 is defined, and the structure and the opening of the partition wall 327 are defined.
  • the thermal viscous effect is increased by the partition wall 327, so that the low sound absorption frequency can be absorbed at a high flaw rate.
  • the thickness of the thermal viscous boundary layer for the movement of air in the inner space is not negligible compared to the size of the inner space. Since the thermal viscosity dissipation effect on the sound propagation in the space inside the Helmholtz resonator 320 is dominant. As a result, the effective sound velocity (v in the above formula) traveling through the inner space is reduced, resulting in a smaller resonance frequency. Accordingly, it is possible to obtain a high sound absorption effect while having a lower sound absorption frequency than an unpartitioned Helmholtz resonator with the same volume. That is, by making the effective sound velocity small by the partition 327 and lengthening the path
  • the four Helmholtz resonators 320 constituting the sound absorbing cell (C3) are all provided with a partition of the same structure, the length of the path of the sound waves may be all the same.
  • the first Helmholtz resonators 320-1 (see FIG. 11) are illustrated, but the second to fourth Helmholtz resonators 320-2 to 320-4 may also have a partition having the same structure.
  • the third embodiment it is possible to extend the path of the sound waves through the partition wall 327, while exhibiting the same sound absorption effect as compared with the sound absorption cell C3 composed of a Helmholtz resonator without the partition wall 327
  • the thickness of the sound absorbing cell C3 can be made thinner.
  • the partition wall 327-2 of the second Helmholtz resonator 320-2 has a structure symmetrical to the partition wall 327-1 of the first Helmholtz resonator 320-1 and the xz plane, and also has a first structure.
  • the partitions 327-1 and 327-2 of the two Helmholtz resonators 320-1 and 320-2 are structures symmetrical to the partition walls of the third and fourth Helmholtz resonators 320-3 and 320-4 and the yz plane. Can be.
  • the position of the hole 325 may be arranged in the same symmetrical structure.
  • the thinner the Helmholtz resonator 320 should be in order to have a high sound absorption rate. It has a thickness and high sound absorption at broadband frequencies.
  • the four Helmholtz resonators 320-1, 320-2, 320-3, and 320-4 that make up the sound absorbing cell C3 are holes 325-1 and 325-2, respectively. , 325-3 and 325-4) may have different sizes, and the volume of the inner space and the thickness of the neck may be the same. That is, by adjusting the sizes of the holes of the four Helmholtz resonators 320-1, 320-2, 320-3, and 320-4 constituting the sound absorbing cell C3, a plurality of specific frequencies can be absorbed at a high sound absorption rate. .
  • the size of the holes 325-1 and 325-2 of 2), that is, the values of r 1 and r 2 are adjusted to completely absorb sound waves having one target frequency, and the third and fourth Helmholtz adjacent to each other.
  • the size of the holes 325-3 and 325-4 of the resonators 320-3 and 320-4, that is, r 3 and r 4 may be adjusted to completely absorb sound waves having another target frequency. have.
  • the values of r 1 , r 2, r 3 , and r 4 can be adjusted through an optimization algorithm such that the difference between the impedance in the sound absorbing device 100 calculated for the two target frequencies and the impedance of the outside air is minimized. . This is as described in the foregoing embodiment.
  • the experimental values represent the results of the specimens produced by 3D printing through impedance tube experiments.
  • the sound absorbing device 100 exhibits a high sound absorbing effect at a plurality of frequencies.
  • the sound absorbing coefficient (a MS) at two frequencies of 300 Hz and 400 Hz is shown. ) Is 0.95 or more, it can be seen that the sound absorption of 95% or more.
  • the thickness of the sound absorbing device is 1 / 24.4 times the incident wavelength.
  • FIG. 13 is a perspective view of a sound absorbing cell constituting the sound absorbing device according to the fourth embodiment of the present invention
  • FIG. 14 is a front view of the sound absorbing cell constituting the sound absorbing device according to the fourth embodiment of the present invention
  • 15 to 17 are perspective views illustrating a Helmholtz resonator constituting the sound absorbing cell of FIG. 14.
  • the sound absorbing device includes a sound absorbing cell C4 composed of eight Helmholtz resonators 420, and the sound absorbing cell C4 is continuous on a plane. It is arranged as.
  • a square column-shaped sound absorbing cell C4 may be configured of eight Helmholtz resonators 420 having a polygonal pillar shape having the same height and having various bottom surfaces.
  • the sound absorbing cell C4 may include four pairs of Helmholtz resonators 420, and are arranged adjacent to each other such that there is no space therebetween to form a square sound absorbing cell C4. can do.
  • the four pairs of Helmholtz resonators 420 constituting the sound absorbing cell C4 may be formed in different sizes of the holes 425. More precisely, the size of the holes 425 may be formed differently between the paired Helmholtz resonators 420, and the size of the holes 425 may be adjusted so that the phases of the reflected sound waves are reversed. Thereby, a high sound absorption effect can be exhibited with respect to a some frequency.
  • the path length of the sound wave in the inner space is the same.
  • the structure of the partition wall 429 provided in the inner space may be the same between the pair of Helmholtz resonators 420.
  • it may have a structure of a hole and a location of a hole symmetrical in the xz plane.
  • the third and fourth Helmholtz resonators 420-3 and 420-4 which are different from the paired first and second Helmholtz resonators 420-1 and 420-2 are sound waves.
  • the lengths of the paths may be different from each other, and thus, sound absorption for the wideband frequency may be realized.
  • the thinner the target sound absorption frequency (or the longer the wavelength of sound waves) the thicker the Helmholtz resonator 420 should be in order to have a high sound absorption rate. The same effect as the thickness of 420 becomes thick can be exhibited.
  • the first and second Helmholtz resonators 420-1 and 420-2 have a hexagonal column having a 'L' shape at the bottom thereof, and a path of sound waves may be extended by the partition wall.
  • the third and fourth Helmholtz resonators 420-3 and 420-4 have a rectangular columnar shape that can be in contact with the concave side surfaces of the first and second Helmholtz resonators 420-1 and 420-2, There may be no bulkhead.
  • the first Helmholtz resonator 420-1 is provided with a partition 427-1 in an internal space, and the partition 427-1 partitions an internal space of the first Helmholtz resonator 420-1. Two planes perpendicular to each other may be coupled to each other, and the openings 429-1 may be formed at ends of opposite directions.
  • the length of the sound wave in the thickness direction (z-axis direction) is the third Helmholtz without the partition shown in FIG.
  • the first and second Helmholtz resonators 420-1 and 420-2 can exhibit a high sound absorption effect at a low frequency
  • the third and fourth Helmholtz resonators 420-3 and 420-4 have a high frequency. High sound absorption effect can be achieved.
  • a Helmholtz resonator having different lengths of sound wave paths in one sound absorbing cell C4 by including a Helmholtz resonator having different lengths of sound wave paths in one sound absorbing cell C4, a high sound absorbing effect can be obtained even when the target sound absorption frequency is large. . In other words, it can exhibit a high sound absorption effect at a wide band frequency.
  • the fifth to eighth Helmholtz resonators 420-5 to 420-8 may have a rectangular pillar shape of the same size, and may have the same path of sound waves.
  • a partition of the same structure may be provided in the interior space.
  • a partition 427-5 is provided in an inner space of the fifth Helmholtz resonator 420-5, and is located far from the hole 425-5 at an end of the partition 427-5. Openings 429-5 may be formed at the ends of the direction.
  • the sound wave passing through the hole 425-5 progresses in the z-axis direction, and the traveling direction is changed through the opening portion 429-5 to proceed in the -z-axis direction, so that the path length of the sound wave is extended.
  • the traveling direction is changed through the opening portion 429-5 to proceed in the -z-axis direction, so that the path length of the sound wave is extended.
  • the fifth to eighth Helmholtz resonators 420-5 to 420-8 have shorter sound paths than the first and second Helmholtz resonators 420-1 and 420-2, but the third and fourth Helmholtz resonators Compared to the resonators 420-3 and 420-4, it may have a longer path of sound waves. That is, the plurality of Helmholtz resonators 420 constituting the sound absorption cell C4 may have paths of at least three different sound waves, and may have at least four sound absorption frequencies (see FIG. 18 to be described below). Accordingly, according to the fourth embodiment, it can be implemented to enable a high sound absorption rate for the frequency of the broadband.
  • the first and second Helmholtz resonators 420-1 which are adjacent to each other in FIGS. 13 and 14, 420-2) is designed to completely absorb sound waves having a first target frequency by adjusting the sizes of the holes 425-1 and 425-2, that is, the values of r 1 and r 2 .
  • the size of the holes 425-3 and 425-4 of the Helmholtz resonators 420-3 and 420-4, that is, r 3 and r 4 can be adjusted to completely absorb sound waves having the second target frequency. Can be.
  • the size of the holes 425-5 and 425-6 of the fifth and sixth Helmholtz resonators 420-5 and 420-6 are adjusted to have a third target frequency.
  • Designed to completely absorb sound waves and by adjusting the size of the holes (425-7, 425-8) of the seventh and eighth Helmholtz resonators (420-7, 420-8) adjacent to each other, that is, r 7 , r 8 It can be designed to completely absorb sound waves having a fourth target frequency.
  • r 1 , r 2 through optimization algorithms such that the difference between the impedance in the sound absorbing device 100 and the impedance of the outside air is minimized.
  • r 3 , r 4 , r 5 , r 6 You can adjust the r 7 and r 8 values.
  • FIG. 18 is a graph showing sound absorption performance of the sound absorbing device according to the fourth embodiment of the present invention.
  • the sound absorbing device 100 according to the fourth embodiment of the present invention exhibits high sound absorption at four frequencies, and includes four frequencies of 300 Hz, 400 Hz, 500 Hz, and 600 Hz. Since the sound absorption coefficient (a MS ) is 0.95 or more, it can be seen that the sound absorption rate of 95% or more can be exhibited. In addition, it can be confirmed that the sound absorbing device 100 according to the fourth embodiment of the present invention is effective for a wideband frequency. A frequency bandwidth capable of exhibiting a sound absorption rate of 50% or more is 36 Hz and 300 Hz target frequencies based on a 300 Hz target frequency. The reference is 44 Hz and 500 Hz. The target frequency is 55 Hz and 600 Hz.
  • the target frequency is 52 Hz.
  • the thickness of the sound absorbing device is 1 / 23.4 times the incident wavelength. Therefore, while implementing a sound absorbing device having a thin thickness similar to the third embodiment, it is possible to implement a sound absorbing device 100 exhibiting a high sound absorption rate for more frequencies and broadband frequencies than the third embodiment.
  • FIG. 19 is a perspective view of a sound absorbing cell constituting the sound absorbing device according to the fifth embodiment of the present invention
  • FIGS. 20 to 23 are perspective views illustrating a Helmholtz resonator constituting the sound absorbing cell of FIG. 19.
  • the sound absorbing device includes a sound absorbing cell C5 composed of eight Helmholtz resonators 520, and the sound absorbing cell C5 includes eight Helmholtz resonators.
  • Two Helmholtz resonators of 520 are arranged adjacent to each other to form four square pillars of the same size, and the four square pillars are arranged adjacent to form a square-shaped sound absorption cell C5. have.
  • the sound absorbing cell C5 may include four pairs of Helmholtz resonators 520, and are arranged adjacent to each other so that there is no space therebetween to form a square sound absorbing cell C5. can do.
  • the four pairs of Helmholtz resonators 520 constituting the sound absorbing cell C5 may have different volumes of internal space. More precisely, a pair of Helmholtz resonators may have the same internal space, but different pairs of Helmholtz resonators may have different internal volumes. Thereby, a high sound absorption effect can be exhibited with respect to a some frequency.
  • the path length of the sound wave in the inner space may be the same.
  • the structure of the partition wall 527 provided in the inner space may be the same between the pair of Helmholtz resonators.
  • it may have a structure of a hole and a location of a hole symmetrical in the xz plane.
  • the neck portion of the Helmholtz resonator 520 in which the internal space is not formed is more than only a part of the front of the Helmholtz resonator 520.
  • the hole 525 is formed in a portion, and the remaining portion may be formed in the inner space without extending the neck portion.
  • the length of the z-axis direction of the inner space directly connected to the hole 525-1 is b, but the z-axis direction of the inner space of the upper position (y-axis direction) of the hole 525-1. The length of becomes b + l.
  • the resonators 520-5 and 520-6 and the seventh and eighth Helmholtz resonators 520-7 and 520-8 may have different path lengths of sound waves, and thus, sound absorption for broadband frequencies may be realized. have. That is, by appropriately arranging a plurality of Helmholtz resonators with different paths of sound waves, high sound absorption can be exhibited for multiple frequencies and wideband frequencies.
  • the first Helmholtz resonator 520-1 has an irregular shape in which a part of a square pillar is divided, and a path of sound waves may be extended by a partition wall.
  • the third Helmholtz resonator 520-3 may be in contact with the concave side surface of the first Helmholtz resonator 520-1, and the first Helmholtz resonator 520-1 and the third Helmholtz resonator 520- 3) may be arranged adjacent to each other to form a square pillar.
  • the fifth Helmholtz resonator 520-5 is an irregular shape in which part of the square pillar is divided, and is different from the first Helmholtz resonator 520-1.
  • the structure may be formed differently from the first Helmholtz resonator 520-1.
  • the seventh Helmholtz resonator 520-7 may be in contact with the concave side of the fifth Helmholtz resonator 520-5, and the fifth Helmholtz resonator 520-5 and the seventh Helmholtz resonator 520- 7) may be arranged adjacent to each other to form a square pillar.
  • two Helmholtz resonators of the eight Helmholtz resonators constituting the sound absorption cell C5 are arranged adjacent to each other to form four square pillar shapes of the same size, and the four square pillar shapes. May be arranged adjacent to each other to form the sound absorption cell.
  • the Helmholtz resonators 420 constituting the sound absorbing cell C4 have the same thickness (the length in the z-axis direction), and two Helmholtz resonators adjacent to each other have the square pillar in the x-axis.
  • the shape of the Helmholtz resonator constituting the sound absorbing cell can be more variously compared with the above-described fourth embodiment, so that the design freedom is high, and thus the length of the path of the sound wave is more precisely. I can adjust it.
  • the difference between target sound absorption frequencies can be reduced, thereby wideband frequency.
  • High sound-absorption effect can be clearly seen at. That is, the plurality of Helmholtz resonators 520 constituting the sound absorbing cell C5 may have four different sound wave paths and may have four sound absorption frequencies.
  • the sound absorbing device 100 In the case of designing the sound absorbing device 100 according to the fifth embodiment of the present invention, it is optimized to minimize the difference between the impedance of the sound absorbing device 100 and the impedance of the outside air in the same manner as described in the previous embodiment.
  • the algorithm r 1 , r 2 , r 3 , r 4 , r 5 , r 6 You can adjust the r 7 and r 8 values.
  • FIG. 24 is a graph showing sound absorption performance of the sound absorbing apparatus according to the fifth embodiment of the present invention.
  • the sound absorbing device 100 according to the fifth embodiment of the present invention exhibits a high sound absorption effect at four frequencies, and includes four frequencies of 375 Hz, 425 Hz, 472 Hz, and 536 Hz. Since the sound absorption coefficient (a MS ) is 0.95 or more, it can be seen that the sound absorption rate of 95% or more can be exhibited. In addition, it can be seen that the sound absorbing device 100 according to the fifth embodiment of the present invention is very effective for a wideband frequency.
  • the frequency bandwidth capable of exhibiting a sound absorption rate of 50% or more is 344 Hz to 533 Hz, which is a total of 209 Hz. .
  • the thickness of the sound absorbing device relative to the incident wavelength is 1 / 18.5 times. Therefore, although the thickness is slightly thicker than that of the fourth embodiment, it is possible to implement the sound absorbing device 100 which exhibits a high sound absorption rate for a much wider frequency band.
  • FIG. 25 is a perspective view of a sound absorbing cell constituting the sound absorbing device according to the sixth embodiment of the present invention.
  • FIG. 26 is a perspective view showing a Helmholtz resonator constituting the sound absorbing cell of FIG. 25, and
  • FIG. 27 is a perspective view of FIG. Front view showing a Helmholtz resonator.
  • the sound absorbing device includes a sound absorbing cell C6 including four Helmholtz resonators 620, and based on the fault cell C6 as a basic unit.
  • the sound absorbing cells C6 are continuously arranged on a plane.
  • the square column-shaped sound absorbing cell C6 may be configured with four Helmholtz resonators 620 having the same size as the square column having a smaller height than the size of the bottom surface.
  • the sound absorbing cell C6 may include four Helmholtz resonators 620, and are arranged adjacent to each other so that there is no space therebetween to form a square sound absorbing cell C6. Can be.
  • the four Helmholtz resonators 620 constituting the sound absorbing cell (C6) may be formed in all different sizes of the holes 625. More precisely, the size of the hole 625 can be adjusted so that the phase of the sound waves reflected between two adjacent Helmholtz resonators 620 or two paired Helmholtz resonators is reversed. Thereby, a high sound absorption effect can be exhibited with respect to a some frequency.
  • the four Helmholtz resonators 620 constituting the sound absorbing cell C6 may have the same length of the path of sound waves in the internal space.
  • the four helmholtz resonators 620 constituting the sound absorbing cell C6 may have the same structure of the partition wall 629 provided in the internal space.
  • each of the four Helmholtz resonators 620 may be formed with a partition 629 so that the path of the sound waves traveling in the inner space is rounded.
  • a sound absorbing device of very thin thickness.
  • the length of the path of the sound wave can be extended while increasing the thermal viscous effect through the partition structure.
  • the z-axis of the Helmholtz resonator 620 is increased while increasing the area.
  • the thickness of the direction may be reduced, and the partition 629 may be configured to have a path of sound waves on the xy plane. Through this, it is possible to minimize the thickness of the sound absorbing device while maximizing the effect of extending the path of sound waves.
  • the first Helmholtz resonator 620-1 has a square pillar shape having a height smaller than that of the bottom surface, and the path of the sound wave is extended by the partition wall 627-1.
  • the partition wall 627-1 may be formed to partition the inner space of the first Helmholtz resonator 620-1 to the same area or to partition the inner space into a lattice shape.
  • the partition wall 627 so that the sound wave incident to the hole 625-1 proceeds in a path of turning in a direction away from the hole 625-1 with respect to the hole 625-1 with respect to the xy plane.
  • a plurality of openings 629-1 may be formed at ⁇ 1).
  • the partition wall 627-1 is in the form of a flat plate extending in the thickness direction (z-axis direction), and as shown in FIG. 27, in the x-axis and y-axis directions with respect to the xy plane. Alternately, it may be in a form of bending multiple times. That is, the opening 629-1 may be disposed in the partition wall 627-1 so as to induce a path in which sound waves turn round. Accordingly, the sound waves incident on the hole 625-1 may not travel in the z-axis direction, which is the thickness direction, but may travel in a path that is alternately bent several times in the x- and y-axis directions.
  • the partition wall 627-1 extends in the x-axis and y-axis directions to partition the internal space in a lattice form based on the xy plane, wherein the opening portion 629- 1) may be formed in a form in which the intermediate wall 627-1 extending in the x- and y-axis directions is emptied so as not to be continuously connected.
  • the path of the sound wave may rotate around the xy plane in a counterclockwise or clockwise direction.
  • the path of the sound waves traveling through the inner space of the first Helmholtz resonator 620-1 may be maximized, and thus the thickness of the first Helmholtz resonator 620-1 may be designed to be very thin.
  • the more partitioned the partition 627-1 partitions the internal space the greater the thermal viscosity effect and the longer the path of the sound waves, and thus, the higher the sound absorption rate at the same target frequency.
  • the thickness of the sound absorbing device 100 may be implemented to be thinner.
  • a partition wall having the same structure as that of the first Helmholtz resonator 620-1 may be provided.
  • a pair of Helmholtz resonators may have a structure of a partition and a position of a hole symmetrical on the x-axis.
  • the partition 627-2 of the second Helmholtz resonator 620-2 has a structure that is symmetrical to the partition 627-1 of the first Helmholtz resonator 620-1 and the x-axis, and the first and the second
  • the partitions 627-1 and 627-2 of the Helmholtz resonators 620-1 and 620-2 may have a structure symmetrical to the partition walls and the y-axis of the third and fourth Helmholtz resonators 620-3 and 620-4. .
  • the third and fourth Helmholtz resonators 620- are designed to completely absorb sound waves having a single target frequency by adjusting the magnitudes of 625-1 and 625-2, that is, r 1 and r 2 .
  • the size of the holes 625-3 and 625-4, ie, r 3 and r 4 , of 3 and 620-4 may be adjusted to completely absorb sound waves having another target frequency.
  • the values of r 1 , r 2, r 3 , and r 4 can be adjusted through an optimization algorithm such that the difference between the impedance in the sound absorbing device 100 calculated for the two target frequencies and the impedance of the outside air is minimized. Is the same as in the above-described embodiment.
  • the sound-absorbing device 100 in accordance with a sixth embodiment of the present invention may determine that exert a high sound absorption effect at a plurality of frequencies, 200 Hz, 250 Hz two kinds of sound absorption coefficient at a frequency (a MS ) Is 0.95 or more, it can be seen that the sound absorption of 95% or more.
  • the thickness of the sound absorbing device 100 can be greatly reduced, and the sound absorbing device 100 has a thickness of 1 / 73.7 times compared to the incident wavelength on the basis of 196 Hz, which is the lowest frequency having a sound absorption rate of 80% or more. Accordingly, similar to the third embodiment, it can be seen that the sound absorption device 100 having a very high sound absorption rate for the dual frequency can be implemented compared to the third embodiment.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
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  • Building Environments (AREA)
  • Soundproofing, Sound Blocking, And Sound Damping (AREA)

Abstract

Un dispositif d'absorption de son selon un mode de réalisation de la présente invention comprend une pluralité de résonateurs de Helmholtz disposés sur un plan, chacun parmi la pluralité de résonateurs de Helmholtz : comprenant une partie col, qui a une épaisseur prédéterminée et à travers laquelle un trou s'étend dans la direction d'épaisseur, et une partie chambre, qui est reliée à la partie col et a un espace intérieur avec lequel des ondes sonores communiquent à travers le trou ; et ayant une fréquence de résonance différente de celle d'un résonateur de Helmholtz adjacent.
PCT/KR2018/011196 2018-03-19 2018-09-20 Dispositif d'absorption de son WO2019182213A1 (fr)

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CN111105774A (zh) * 2019-10-29 2020-05-05 同济大学 亥姆霍兹共振器及基于其的低频宽带吸声降噪结构
CN111696507A (zh) * 2020-06-01 2020-09-22 西安交通大学 一种阻尼层修饰的水下吸声内插管式亥姆霍兹共鸣腔结构
CN111696508A (zh) * 2020-06-01 2020-09-22 西安交通大学 一种粗糙内插管式亥姆霍兹共振吸声结构
CN111696504A (zh) * 2020-06-01 2020-09-22 西安交通大学 一种花瓣形内插管式水下亥姆霍兹共鸣腔结构
CN112103975A (zh) * 2020-09-11 2020-12-18 南京大学 一种基于共鸣器kagome阵列的声学拓扑储能结构
CN112669802A (zh) * 2020-12-11 2021-04-16 南京光声超构材料研究院有限公司 吸声结构及吸声装置
CN113096626A (zh) * 2021-03-30 2021-07-09 南京光声超构材料研究院有限公司 静音箱
CN113362799A (zh) * 2021-03-29 2021-09-07 浙江工业大学 声波导中宽频带声能量的定向传播和局部化控制方法
CN113362796A (zh) * 2021-05-10 2021-09-07 西安交通大学 一种双向粗糙内插管式亥姆霍兹共振吸声结构
CN113393827A (zh) * 2021-06-08 2021-09-14 北京航空航天大学 一种改变吸声频率的主/被动控制Helmholtz共振器
US11867139B1 (en) 2022-06-17 2024-01-09 Blue Origin, Llc Multi-volume acoustic resonator for rocket engine

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Cited By (17)

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Publication number Priority date Publication date Assignee Title
CN111105774A (zh) * 2019-10-29 2020-05-05 同济大学 亥姆霍兹共振器及基于其的低频宽带吸声降噪结构
CN111696507B (zh) * 2020-06-01 2023-03-28 西安交通大学 一种阻尼层修饰的水下吸声内插管式亥姆霍兹共鸣腔结构
CN111696507A (zh) * 2020-06-01 2020-09-22 西安交通大学 一种阻尼层修饰的水下吸声内插管式亥姆霍兹共鸣腔结构
CN111696508A (zh) * 2020-06-01 2020-09-22 西安交通大学 一种粗糙内插管式亥姆霍兹共振吸声结构
CN111696504A (zh) * 2020-06-01 2020-09-22 西安交通大学 一种花瓣形内插管式水下亥姆霍兹共鸣腔结构
CN111696508B (zh) * 2020-06-01 2023-03-28 西安交通大学 一种粗糙内插管式亥姆霍兹共振吸声结构
CN111696504B (zh) * 2020-06-01 2023-03-28 西安交通大学 一种花瓣形内插管式水下亥姆霍兹共鸣腔结构
CN112103975A (zh) * 2020-09-11 2020-12-18 南京大学 一种基于共鸣器kagome阵列的声学拓扑储能结构
CN112669802A (zh) * 2020-12-11 2021-04-16 南京光声超构材料研究院有限公司 吸声结构及吸声装置
CN113362799B (zh) * 2021-03-29 2022-03-18 浙江工业大学 声波导中宽频带声能量的定向传播和局部化控制方法
CN113362799A (zh) * 2021-03-29 2021-09-07 浙江工业大学 声波导中宽频带声能量的定向传播和局部化控制方法
CN113096626A (zh) * 2021-03-30 2021-07-09 南京光声超构材料研究院有限公司 静音箱
CN113362796A (zh) * 2021-05-10 2021-09-07 西安交通大学 一种双向粗糙内插管式亥姆霍兹共振吸声结构
CN113362796B (zh) * 2021-05-10 2024-05-24 西安交通大学 一种双向粗糙内插管式亥姆霍兹共振吸声结构
CN113393827A (zh) * 2021-06-08 2021-09-14 北京航空航天大学 一种改变吸声频率的主/被动控制Helmholtz共振器
CN113393827B (zh) * 2021-06-08 2022-05-10 北京航空航天大学 一种改变吸声频率的主/被动控制Helmholtz共振器
US11867139B1 (en) 2022-06-17 2024-01-09 Blue Origin, Llc Multi-volume acoustic resonator for rocket engine

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