CN115273792A - Acoustic device based on phononic crystal theory - Google Patents
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- CN115273792A CN115273792A CN202210867576.2A CN202210867576A CN115273792A CN 115273792 A CN115273792 A CN 115273792A CN 202210867576 A CN202210867576 A CN 202210867576A CN 115273792 A CN115273792 A CN 115273792A
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- 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
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- G10K11/18—Methods or devices for transmitting, conducting or directing sound
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Abstract
The invention discloses an acoustic device based on a phononic crystal theory, which adopts C-shaped scatterers to be vertically arranged in a matrix to form a phononic crystal unit cell, wherein the phononic crystal unit cell is combined with a rectangular phononic crystal super-cell structure in a triangular lattice mode, sound waves are normally incident to the phononic crystal super-cell structure from one side of the phononic crystal super-cell structure, and the topological phase of the sound waves is changed by rotating the scatterers in each area; when phononic crystals of different topological phases are combined, a topological valley polarization boundary state can be generated at an interface, and a multifunctional acoustic device can be manufactured by utilizing the directional propagation characteristic, the unidirectional propagation characteristic, the backscattering inhibition and the robustness characteristic of the self sound.
Description
Technical Field
The invention belongs to the technical field of acoustic devices, and particularly relates to an acoustic device based on a phonon crystal theory.
Background
With the development of research in the acoustic field, the regulation and control of sound waves are more and more concerned by broad learners, such as sound gathering and propagation, sound propagation path change, sound propagation path opening and closing control, and the like. The discovery of the phononic crystal brings a brand new idea for the design of the acoustic device, and accordingly, numerous scholars design various acoustic devices based on the phononic crystal theory to achieve the regulation and control of sound waves.
The acoustic device designed in the past has a complex structure and higher required precision. And in practical application, external disturbance cannot be avoided. When there is a disturbance or loss of structure, the functional efficiency of the acoustic device is reduced or even disabled. The proposed phononic crystal brings a new idea for regulating and controlling sound waves, and the characteristic of the phononic crystal has guiding significance for the design of an acoustic device. In the prior art, the phononic crystal is utilized to carry out sound gathering propagation and change the sound propagation path mainly through point defect/line defect in the phononic crystal supercell, the method has simple structure and is easy to manufacture and operate, but the sound energy loss is larger after sound waves pass through the phononic crystal, and the efficiency is lower. The unidirectional sound propagation is mainly realized by modulating time and space, wherein the method for modulating the time has a poor one-way effect due to the lower conversion rate of a nonlinear medium and the existence of a non-synergistic effect, and the method for modulating the space has a better one-way effect than the former one, but has a more complex and fixed structure.
In view of this, it is of great significance to design a high-efficiency, simple-structure and external disturbance-resistant multifunctional acoustic device by using the phononic crystal theory and combining the above functions of regulating and controlling the sound wave.
Disclosure of Invention
The technical problem to be solved by the present invention is to provide an acoustic device based on the phononic crystal theory, which is based on the phononic crystal theory to construct a two-dimensional phononic crystal supercell structure, and combines phononic crystals of different topological phases in each region of the supercell structure to generate a topological valley polarization boundary state at an interface, and utilizes the directional propagation, unidirectional propagation, backscattering inhibition and robustness characteristics of the boundary, so as to effectively regulate and control the acoustic wave.
The invention adopts the following technical scheme:
an acoustic device based on a phononic crystal theory comprises a plurality of phononic crystal unit cells, wherein the plurality of phononic crystal unit cells are arranged in a triangular lattice mode to form the acoustic device, each phononic crystal unit cell comprises a scatterer, and the scatterer is of a C-shaped structure with chiral characteristics and is vertically arranged in a matrix.
Specifically, the scatterer 1 can rotate clockwise or counterclockwise around its geometric center, and the rotation angle is α.
Further, the phononic crystal unit cell when α = -20 ° is phononic mode a; phononic crystal unit cell when α =20 ° is phononic mode B; phononic crystal unit cell when α =0 ° is phononic mode C; phonon mode a, phonon mode B, and/or phonon mode C constitute an acoustic waveguide device, an acoustic diode device, or an acoustic switching device.
Furthermore, the frequency of the phononic crystal unit cell is 9000-11000 Hz.
Further, when the angle is rotated by alpha<At the time of 0, the number of the first,
Cv=1 < 0, when rotated by an angle α>At the time of 0, the number of the first,
Cv＝1＞0，
is the topological index of the phononic crystal after the scatterer rotates anticlockwise,
for phononic crystals after clockwise rotation of the diffuserTopological index, CvThe number of grains is shown.
Specifically, the outer ring radius of the scatterer is 0.4a, the inner ring radius of the scatterer is 0.2a, and a is the lattice constant of the phononic crystal unit.
Specifically, the opening angle of the diffuser is 120 °.
Specifically, the scatterers are steel.
Specifically, the substrate is air.
Specifically, the acoustic device is a phononic crystal superlattice structure with a rectangular structure.
Compared with the prior art, the invention has at least the following beneficial effects:
the invention relates to an acoustic device based on a phononic crystal theory, which constructs a phononic crystal unit cell structure by combining a scatterer and a matrix so as to construct a phononic crystal supercell; the scatterer is in a C shape, the C shape has chiral characteristics, the phononic crystal is combined with the chiral characteristics, so that a phononic crystal unit cell has rich band gaps, the band gap frequency range is lower, more frequency range selections are provided for users to meet actual working conditions, the sound waves can be regulated and controlled only by rotating the C-shaped scatterers in all regions, the operation is simple and convenient, sound directional propagation, sound unidirectional propagation and control of opening and closing of sound wave propagation paths can be realized only by changing the topological phases of the scatterers in different regions, the combination of functions of various acoustic devices is realized, the sound energy loss in the sound wave propagation process is small, the efficiency is high, and the influence of external disturbance is small.
Further, by rotating the scatterer 1 clockwise or counterclockwise around the geometric center thereof, the topological phase of the phononic crystal can be changed, a topological valley polarization boundary state is generated, and the multifunctional acoustic device works by utilizing the characteristic. The method is simple and convenient to operate, and the functions of various acoustic devices can be switched only by controlling the rotation angle of the scatterer.
Furthermore, the rotation angles of the two phononic crystal unit-cell scatterers designed in the patent are α =20 ° and α = -20 ° respectively, which only represents one case, and in practical application, it is only required to satisfy that the rotation angles α of the two phononic crystal unit-cell scatterers are opposite to each other.
Furthermore, the frequency of the phononic crystal unit cell designed by the patent is 9000-11000 Hz, which only represents one condition, and the phononic crystal unit cell needs to be designed according to the frequency band required by the actual working condition in practical application.
Further, when the angle alpha is rotated<At the time of 0, the number of the first,
Cv=1 < 0, when rotated by an angle α>At the time of 0, the number of the first,
Cv=1 > 0. This indicates that clockwise rotation and counterclockwise rotation have opposite valley counts, and the phononic crystal combination with two opposite valley counts will have topological valley polarization boundary states at the interface according to the volume-boundary correspondence principle, and the designed acoustic device will work by using the characteristic.
Furthermore, the outer ring radius of the scatterer of the phononic crystal unit cell designed by the patent is 0.4a, the inner ring radius of the scatterer is 0.2a, a represents only one condition for the lattice constant of the phononic crystal unit cell, and the geometric dimension of the phononic crystal unit cell needs to be modified according to the frequency band required by the actual working condition in the practical application.
Furthermore, the opening angle of the diffuser of the phononic crystal unit cell designed by the patent is 120 degrees, which only represents one situation, and the geometric dimension of the phononic crystal unit cell needs to be modified according to the frequency band required by the actual working condition in the actual application.
Furthermore, the condition that the scatterer of the phononic crystal unit cell designed by the application is steel only represents one condition, and in practical application, the material attribute of the scatterer of the phononic crystal unit cell needs to be modified according to the frequency band required by the practical working condition.
Furthermore, the matrix of the phononic crystal unit cell designed by the patent represents only one condition for air, and in practical application, the matrix material attribute of the phononic crystal unit cell needs to be modified according to the frequency band required by the practical working condition.
Furthermore, the acoustic device designed by the patent is a rectangular-structure phononic crystal supercell structure which only represents one condition, and the structural shape of the phononic crystal supercell needs to be modified according to actual working conditions in practical application.
In summary, the acoustic device has the advantages of simple structure, convenient operation, high efficiency and strong robustness.
The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.
Drawings
Fig. 1 is a schematic unit cell diagram of an acoustic device of the present invention, wherein (a) is a phononic crystal initial unit cell structure, (b) is a phononic crystal unit cell structure at α =20 °, and (c) is a phononic crystal unit cell structure at α = -20 °;
FIG. 2 is a schematic view of a phononic crystal superlattice of an acoustic device of the present invention;
FIG. 3 is a band structure of a unit cell of an acoustic device of the present invention;
FIG. 4 is a diagram showing the band structure of a strip-shaped supercell composed of two kinds of phononic crystals A and B, wherein (a) is the band structure of the strip-shaped supercell, (B) is a partial enlarged view of the position P, and (c) is a partial enlarged view of the position Q;
FIG. 5 is a schematic diagram of a phononic crystal super cell of a device with an ABA structure and modified from a model according to the present invention;
fig. 6 is a numerical simulation of the sound pressure field of a sound wave with a frequency of F =10870Hz incident on the acoustic diode acoustic device from the left side;
FIG. 7 is a graph showing the variation of the transmission coefficient of sound waves at the AB linear interface and the BA linear interface with the frequency of the sound waves;
FIG. 8 is a schematic view of a phononic crystal ultrasound cell of the present invention with a modified model of acoustic waveguide device (boundary path in "Z" shape);
fig. 9 is a numerical simulation of the acoustic pressure field incident on the acoustic waveguide device from the left for a sound wave having a frequency of F =10870 Hz;
FIG. 10 is a graph showing the variation of the transmission coefficient at the BA linear interface and the BA "Z" -shaped interface with the acoustic frequency when the acoustic wave is incident on the left side, respectively;
FIG. 11 is a schematic view of an acoustic waveguide device photonic crystal ultrasound cell of the present invention with a model modified to include a defect, with inset showing a local magnification of the defect;
fig. 12 is a numerical mode of an acoustic pressure field of an acoustic wave with a frequency of F =10870Hz incident from the left side to an acoustic waveguide device including a defect state;
FIG. 13 is a schematic view of a phononic crystal ultrasound cell of an acoustic waveguide device of the present invention with the model modified to include a disordered state, with the inset showing a local enlargement of the disorder;
fig. 14 is a numerical mode of an acoustic pressure field of an acoustic wave with a frequency of F =10870Hz incident from the left side to an acoustic waveguide device including a disorder state;
fig. 15 is a graph showing the change of the transmission coefficient with respect to the acoustic wave frequency of the acoustic waveguide device including the complete acoustic waveguide device, the acoustic waveguide device including the defect state, and the acoustic waveguide device including the disorder state, in which the acoustic wave is incident on the left side, respectively;
FIG. 16 is a diagram of a phononic crystal supercell in which the model is changed to an acoustic switching device according to an embodiment of the present invention;
fig. 17 is a numerical simulation of the acoustic pressure field of an acoustic switching device capable of letting an acoustic wave with a frequency F =10870Hz enter from port 1 and exit from port 3;
fig. 18 is a numerical simulation of the acoustic pressure field of an acoustic switching device capable of emitting sound waves with a frequency of F =10870Hz from port 1 and out of port 2;
fig. 19 is a numerical simulation of the acoustic pressure field of an acoustic switching device capable of letting sound waves with a frequency of F =10870Hz enter from port 1 and exit from port 4;
fig. 20 is a numerical simulation of the acoustic pressure field of the acoustic switching device in which the acoustic wave having the frequency of F =10870Hz is incident from the port 1 and the ports 2 and 4 are simultaneously emitted.
Wherein: 1. a scatterer; 2. a substrate.
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 some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "one side", "one end", "one side", and the like indicate orientations or positional relationships based on those shown in the drawings, merely for convenience of description and simplification of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and therefore, are not to be construed as limiting the present invention. In addition, in the description of the present invention, "a plurality" means two or more unless otherwise specified.
In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
It will be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
It is also to be understood that the terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the specification of the present invention and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.
It should be further understood that the term "and/or" as used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.
Various structural schematics according to the disclosed embodiments of the invention are shown in the drawings. The figures are not drawn to scale, wherein certain details are exaggerated and possibly omitted for clarity of presentation. The shapes of various regions, layers and their relative sizes and positional relationships shown in the drawings are merely exemplary, and deviations may occur in practice due to manufacturing tolerances or technical limitations, and a person skilled in the art may additionally design regions/layers having different shapes, sizes, relative positions, according to actual needs.
The invention provides an acoustic device based on a phononic crystal theory, which is a rectangular phononic crystal super-cell structure formed by combining a triangular lattice mode, wherein a scatterer is C-shaped and can rotate clockwise or anticlockwise around a geometric center of the scatterer, the scatterer is made of steel, and a base body is made of air. The scatterers are vertically arranged in the matrix, sound waves are normally incident to the photonic crystal superlattice structure from one side of the photonic crystal superlattice structure, and the topological phases of the scatterers are changed by rotating the scatterers in all the areas. When phononic crystals of different topological phases are combined, a topological valley polarization boundary state can be generated at an interface, and a multifunctional acoustic device can be manufactured by utilizing the directional propagation characteristic, the unidirectional propagation characteristic, the backscattering inhibition and the robustness characteristic of the self sound.
Referring to fig. 1 and 2, the acoustic device based on the phononic crystal theory of the present invention is a phononic crystal supercell structure, which is rectangular and includes a plurality of unit cells arranged in a triangular lattice manner, wherein the unit cells include a scatterer 1 and a substrate 2.
The scatterer 1 of the unit cell is steel, and the matrix 2 of the unit cell is air.
The scatterer 1 is in a C shape with chiral characteristics, is vertically arranged in a matrix 2 of the unit cell to form a periodic structure, and can rotate clockwise or anticlockwise around the geometric center of the scatterer 1. The sound wave is normally incident to the photonic crystal superlattice structure from one side of the photonic crystal superlattice structure.
The lattice constant of the unit cell is a, the outer ring radius of the scatterer 1 is 0.4a, the inner ring radius of the scatterer 1 is 0.2a, and the opening angle of the scatterer 1 is 120 °.
The diffuser 1 is in the shape of a "C" which can be rotated clockwise or anticlockwise around the geometric centre by an angle α, as shown in figure 1 (b), the dark dotted line representing the positions of the upper and lower ports after the diffuser has been rotated.
For convenience of description, the unit cell structure when α = -20 ° is defined as phonon mode a;
the unit cell structure when α =20 ° is defined as phonon mode B;
the unit cell structure when α =0 ° is defined as phonon mode C.
The single cells are arranged in a triangular lattice manner and combined into a phononic crystal super-cell structure, namely the initial structure of the multifunctional acoustic device based on the phononic crystal theory, which is provided by the invention, is shown in fig. 2.
Referring to fig. 3, a dirac point is formed at a high symmetry point X in a phonon mode a, and if the scatterer 1 is rotated by 20 ° clockwise or counterclockwise around a geometric center, that is, the energy band structures of the phonon mode B and the phonon mode C are the same, the dirac point at the high symmetry point X is opened to form a band gap with a frequency range of 9000 to 11000Hz, a sound wave within the frequency band cannot propagate, a sound wave outside the frequency band can propagate, and analysis shows that α =20 ° and α = -20 ° have different topological phases, which means that a valley hall phase change occurs during the process of changing the scatterer from α =20 ° to α =20 °.
Based on a k.p disturbance method, the elastic valley Hall phase change is described by an effective Hamilton quantity near a Dirac point:
wherein v isDIs the dirac velocity, σiRepresents the pauli matrix, m represents the effective mass, represented by equation (2):
wherein, ω isiRepresents the upper and lower frequencies of the band gap, +, -represents the direction of rotation, + is clockwise, -is counter-clockwise.
The Berry curvature distribution of the first band can be known from the formula (1):
integrating the topological index to obtain an expression of the topological index:
when the rotation angles of the scatterers are opposite numbers to each other,
according to a calculation formula of the millet aging number:
when rotating by an angle alpha<At the time of 0, the number of the first,
Cv=1 < 0, when rotated by an angle α>At the time of 0, the number of the first,
Cv＝1＞0。
the results show that the topological valley polarization boundary states exist at the interface formed by two phononic crystals with opposite valley counts.
The phonon mode A and the phonon mode B are combined to form a combined unit cell, the energy band structure of the combined unit cell is shown as figure 4 (a), a solid line and a dotted line in the figure represent a topological valley polarization boundary state, the corresponding frequency range is 9000-11000 Hz, and figures 4 (B) and 4 (c) are partial enlarged images at positions P and Q respectively, and show that the topological valley polarization boundary state has sound unidirectional transmission characteristics.
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, 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 some, but not all, embodiments of the present invention. The components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be obtained by a person skilled in the art without inventive step based on the embodiments of the present invention, are within the scope of protection of the present invention.
The invention provides an acoustic device based on a phonon crystal theory, which has the working effect of an acoustic diode device, and the concrete operation is as follows: the multifunctional acoustic device is divided into an upper part and a lower part, a scatterer on the upper half part of the multifunctional acoustic device is rotated to be in a phonon mode B, a scatterer on the lower half part of the multifunctional acoustic device is rotated to be in a phonon mode A, and the multifunctional acoustic device can be constructed into an acoustic diode device.
In order to reflect the effect more intuitively, the multifunctional acoustic device is divided into three parts, the scatterers at the upper part and the lower part are rotated to be in a phonon mode A, the scatterer at the middle part is rotated to be in a phonon mode B (called as an ABA structure), as shown in fig. 5, the numerical simulation of the sound pressure field after sound pressure is applied to the right side of the multifunctional acoustic device is shown in fig. 6, and it can be seen from the figure that sound waves can be transmitted along a BA interface but an AB interface cannot pass through. The change of the transmission coefficients of the AB interface and the BA interface with the frequency is shown in fig. 7, and it can be known from the graph that in the 9000-12000 Hz frequency band range corresponding to the topological boundary state, the attenuation amplitude of the transmission coefficient of the AB interface (black solid line) is large, and the transmission coefficient of the BA interface (red dotted line) is substantially not attenuated, and the above results indicate that the multifunctional acoustic device can achieve the working effect of the acoustic diode device.
The acoustic device based on the phononic crystal theory provided by the invention has the working effect of an acoustic waveguide device, the waveguide path of the acoustic device is not limited to the following situation, and the following examples are described, and the concrete operation is as follows: the multifunctional acoustic device is divided into a left part and a right part, a scatterer of the left half part of the multifunctional acoustic device is rotated to be in a phonon mode B, a scatterer of the right half part of the multifunctional acoustic device is rotated to be in a phonon mode A, and a junction surface between the left part and the right part is in a Z shape, so that the multifunctional acoustic device can be constructed into an acoustic waveguide device as shown in fig. 8.
In order to reflect the effect more intuitively, the numerical simulation of the sound pressure field after sound pressure is applied to the right side of the multifunctional acoustic device is shown in fig. 8, and it can be known from the figure that sound waves propagate along the interface in a shape like a Chinese character 'Z', the sound pressure intensity of the whole interface is uniform, scattering is not observed at two obtuse angles, and the result shows that the multifunctional acoustic device can achieve the working effect of the sound waveguide device. The transmission coefficient of the linear BA interface in fig. 6 and the transmission coefficient of the "Z" BA interface in fig. 8 varies with frequency as shown in fig. 9, and it can be seen from the graph that there is almost no difference in the transmission curve in the range of 9000 to 11000Hz, which proves that the topological valley polarization boundary state is not scattered at the obtuse angle of the "Z" interface, and the above results show that the multifunctional acoustic device has backscattering suppression when it is an acoustic waveguide device.
Further, a scatterer defect condition and a scatterer disturbance condition are introduced around the "Z" shaped boundary path of the acoustic waveguide device, respectively, as shown in fig. 11 and 13, respectively, and the insets show partial enlarged views of the scatterer defect and the scatterer disturbance. The numerical simulations of the sound pressure field after sound pressure application to the right side of the multifunctional acoustic device in the two conditions are shown in fig. 12 and 14, respectively, and it is understood from the figures that the sound wave can still propagate along the zigzag interface. The transmission coefficient of the complete acoustic waveguide acoustic device, the transmission coefficient of the acoustic waveguide acoustic device containing the scatterer defect condition and the transmission coefficient of the acoustic waveguide acoustic device containing the scatterer disorder condition along with the change of frequency are shown in fig. 15, and it can be known from the graph that three curves are basically fitted, the defects and disorders of the scatterer basically have no influence on the sound transmission, and the above results show that when the multifunctional acoustic device is an acoustic waveguide device, the multifunctional acoustic device has robustness on the defects and disorders of the scatterer.
The acoustic device based on the phononic crystal theory provided by the invention has the working effect of an acoustic switch device, and the concrete operation is as follows: as shown in fig. 16, the horizontal and vertical interfaces (red solid lines) intersect at the center of the model, and divide the original multifunctional acoustic device into four regions, where the four input/output ports are respectively labeled with 1, 2, 3, and 4, the model center is used as a demarcation point, the horizontal boundary and the vertical boundary are divided into four channels respectively labeled with L, R, U, and D, and the working effect of the acoustic switching device is achieved by rotating the scatterers of the regions.
For a more intuitive reflection effect, the following example will now be described: applying sound pressure to the right side of the acoustic switching device, and when the upper left area and the upper right area are in a phonon mode B and the lower left area and the lower right area are in a phonon mode A, simulating the sound pressure field numerical value as shown in FIG. 17, wherein it can be seen from the figure that sound waves are incident from a port 1 and are emitted from a port 3 through a channel L and a channel R; when the upper left region is the phonon mode B and the lower left region, the upper right region and the lower right region are the phonon mode a, the numerical simulation of the sound pressure field is as shown in fig. 18, and it can be seen from the figure that sound waves are incident from the port 1 and are emitted from the port 2 through the channel L and the channel U; when the upper left area, the upper right area and the lower right area are in the phonon mode B and the lower left area is in the phonon mode a, the numerical simulation of the sound pressure field is as shown in fig. 19, and it can be seen from the figure that sound waves are incident from the port 1 and are emitted from the port 4 through the channel L and the channel D; when the upper left and right regions are phonon mode B and the lower left and right regions are phonon mode a, the numerical simulation of the sound pressure field is as shown in fig. 20, and it can be seen from the figure that sound waves are incident from port 1 and simultaneously exit from ports 2 and 4 through channels L, U and D. The above results show that the multifunctional acoustic device can achieve the working effect of the acoustic switching device.
In summary, the acoustic device based on the phononic crystal theory of the present invention only needs to rotate the rotation angle of the scatterer of the phononic crystal, and a topological valley polarization boundary state is generated at the interface of different topological phases. The multifunctional acoustic device is manufactured by utilizing the acoustic directional propagation characteristic and the acoustic unidirectional propagation characteristic of the topological valley polarization boundary state, the acoustic device combines the working effects of three acoustic devices, namely an acoustic waveguide device, an acoustic diode device and an acoustic switch device, and has the advantages of simple structure, simplicity and convenience in operation, high working efficiency, strong backscattering inhibition performance and robustness and the like.
The above-mentioned contents are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modification made on the basis of the technical idea of the present invention falls within the protection scope of the claims of the present invention.
Claims (10)
1. An acoustic device based on a phononic crystal theory is characterized by comprising a plurality of phononic crystal unit cells, wherein the plurality of phononic crystal unit cells are arranged in a triangular lattice mode to form the acoustic device, each phononic crystal unit cell comprises a scatterer (1), the scatterer (1) is of a C-shaped structure with a chiral characteristic, and the scatterer is vertically placed in a matrix (2).
2. The phononic crystal theory based acoustic device according to claim 1, wherein the scattering body 1 is rotatable around its geometrical center clockwise or counterclockwise by a rotation angle α.
3. The phononic crystal theory based acoustic device of claim 2 wherein the phononic crystal unit cell when α = -20 ° is phononic mode a; phononic crystal unit cell when α =20 ° is phononic mode B; phononic crystal unit cell when α =0 ° is phononic mode C; phonon mode a, phonon mode B, and/or phonon mode C constitute an acoustic waveguide device, an acoustic diode device, or an acoustic switching device.
4. The phononic crystal theory based acoustic device of claim 3 wherein the frequency of the phononic crystal unit cell is 9000-11000 Hz.
5. An acoustic device based on phononic crystal theory according to claim 3, characterized in that when rotated by an angle α<At the time of 0, the number of the first,
Cv=1 < 0, when rotated by an angle α>At the time of 0, the number of the first,
Cv＝1＞0，
is the topological index of the phononic crystal after the scatterer rotates anticlockwise,
is the topological index, C, of the phononic crystal after the clockwise rotation of the scatterervThe number of grains is shown.
6. The phononic crystal theory based acoustic device according to claim 1, characterized in that the outer ring radius of the scatterer (1) is 0.4a, the inner ring radius of the scatterer (1) is 0.2a, a is the lattice constant of the phononic crystal unit cell.
7. The phononic crystal theory based acoustic device according to claim 1, characterized in that the opening angle of the scatterer (1) is 120 °.
8. The phononic crystal theory based acoustic device according to claim 1, characterized in that the scatterer (1) is steel.
9. An acoustic device based on phononic crystal theory according to claim 1, characterized in that the substrate (2) is air.
10. The photonic crystal theory-based acoustic device according to any one of claims 1 to 9, wherein the acoustic device is a photonic crystal superlattice structure having a rectangular-shaped structure.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115588423A (en) * | 2022-11-23 | 2023-01-10 | 南京南大电子智慧型服务机器人研究院有限公司 | Broadband high-directivity topological sound wave radiation antenna |
| CN115826136A (en) * | 2022-11-26 | 2023-03-21 | 天津大学 | Double-bandwidth valley Hall polarization twisted-state waveguide based on triangular lattice valley photonic crystal |
| CN116318034A (en) * | 2023-03-22 | 2023-06-23 | 北京深谋科技有限公司 | Surface acoustic wave device with topology transport function and regulation and control method and application thereof |
| US20240021187A1 (en) * | 2022-07-13 | 2024-01-18 | Toyota Motor Engineering & Manufacturing North America, Inc. | Beaming sound waves using phononic crystals |
| CN115826136B (en) * | 2022-11-26 | 2024-05-14 | 天津大学 | Double-bandwidth Gu Huoer polarization twisted waveguide based on triangular lattice Gu Guangzi crystal |
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2022
- 2022-07-22 CN CN202210867576.2A patent/CN115273792A/en active Pending
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20240021187A1 (en) * | 2022-07-13 | 2024-01-18 | Toyota Motor Engineering & Manufacturing North America, Inc. | Beaming sound waves using phononic crystals |
| CN115588423A (en) * | 2022-11-23 | 2023-01-10 | 南京南大电子智慧型服务机器人研究院有限公司 | Broadband high-directivity topological sound wave radiation antenna |
| CN115826136A (en) * | 2022-11-26 | 2023-03-21 | 天津大学 | Double-bandwidth valley Hall polarization twisted-state waveguide based on triangular lattice valley photonic crystal |
| CN115826136B (en) * | 2022-11-26 | 2024-05-14 | 天津大学 | Double-bandwidth Gu Huoer polarization twisted waveguide based on triangular lattice Gu Guangzi crystal |
| CN116318034A (en) * | 2023-03-22 | 2023-06-23 | 北京深谋科技有限公司 | Surface acoustic wave device with topology transport function and regulation and control method and application thereof |
| CN116318034B (en) * | 2023-03-22 | 2023-10-27 | 北京深谋科技有限公司 | Surface acoustic wave device with topology transport function and regulation and control method and application thereof |
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