KR20150086943A - Method and Apparatus of Cloaking for Acoustic Waves - Google Patents

Abstract

Disclosed in the present invention are a method for concealing acoustic waves and an apparatus thereof. According to an embodiment of the present invention, the method for concealing acoustic waves comprises: a step of transforming an acoustic wave transmission mathematical model into an acoustic wave concealment mathematical model corresponding to an electromagnetic wave mathematical model based on a correlation between the acoustic wave mathematical model, predetermined acoustic wave transmission, and the electromagnetic wave mathematical model, predetermined electromagnetic waves; a step of drawing target characteristics of a metamaterial using the transformed acoustic wave concealment mathematical model; and a step of arranging the metamaterial with the drawing target characteristics around an area including an object in order to shield the area from acoustic waves. The electromagnetic wave mathematical model includes a mathematical model of Maxwell′s equation. The step of transforming into the acoustic wave concealment mathematical model substitutes the acoustic wave transmission mathematical model into a relativistic coordinate space transformation method based on the Maxwell′s equation in order to transform the acoustic wave transmission mathematical model into the acoustic wave concealment mathematical model.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method and apparatus for concealing sound waves,

The present invention relates to a metamaterial, and more particularly, to a method and apparatus for blocking the transmission of a sound wave to a specific region using a meta-material and blocking a sound wave of a specific object from being transmitted to the outside.

Recent research on meta-materials has enabled microscopic and macroscopic control of electromagnetic fields [Phys.Rev.Lett. 85, 3966 (2000); Science 312,1777 (2006); Science 312, 1780 (2006)). A metamaterial is an artificial method that can not be obtained in a normal natural state. An unusual point of a metamaterial is that it has a negative refractive index, so that the light in the metamaterial warps in the opposite direction .

Using these metamaterials, it was possible to adjust the direction of the electromagnetic field freely irrespective of the source of the electromagnetic field, and to guide the object as if there were no objects [Science 312, 1777 (2006); Science 312, 1780 (2006)). This can potentially be applied to radiation shielding from strong electromagnetic field pulses (EMP) or directional electromagnetic energy.

Electromagnetic field control using metamaterials has attracted great interest in the field of novel applications such as invisibility cloak, concentrator, and refractor.

Among them, the transparency cloak is the most attractive application by hiding objects inside a given geometric shape. Transparent cloaks are based on coordinate transformations and conformal mapping of the Maxwell equations. These translucent cloaks are based on Pendry [Science 312, 1780 (2006)] and Leonhardt [Science 312, 1777 (2006) ], Respectively.

Full-wave electromagnetic simulations of cylindrical cloaks using ideal or non-ideal electromagnetic parameters have been studied and experimental implementations of cylindrical cloaks with simple parameters operating at microwave frequencies have been published.

In analyzing and designing the transparency device, it is most important to calculate the dielectric constant tensor and the transmittance tensor for the metamaterial constituting the transparent shell.

The transparency device assumes that the field line will distort the field line so that it will move away from that area in some area having a uniform field line, which is considered to be a coordinate transformation between the original Cartesian mesh and the distortion mesh .

The theoretical and experimental implementations of such a conventional translucent device have been greatly influenced by the direction of the electromagnetic wave, the polarization, and the wavelength band. "Complementary media invisibility cloak that cloaks objects at a distance outside the cloaking shell," Y. Lai, H. Chen, Z. Q. Zhang, and C. Chan, Phys. Rev. Lett. 102,93901 (2009). (Publication Date 2009.03.02) proposed a technique for improving the efficiency of an invisible cloak using complementary media, but the prior art herself indicates that the prior art is effective at a finite frequency.

An attempt to overcome these limitations and extend them to applicable theories in a more general case is described in Doyeol Ahn, Journal of Modern Optics, Volume 58, Issue 8, 2011, entitled "Calculation of Permittivity Tensors for Invisibility Devices in General Relativity" (Published on April 21, 2011) and Korean Patent Laid-Open Publication No. 10-2013-0047860 (published on March 20, 2013).

This prior art approach can be scaled by the factors obtained by coordinate transformation or optical conformal mapping techniques while maintaining the form of the Maxwell's equation that does not change in any coordinate system.

In addition, methods of calculating permittivity tensors and permeability tensors for transparency devices using electrodynamics in the framework of the theory of relativity have also been studied.

The principle ideal of the prior art is based on the fact that the propagation of electromagnetic waves in a curved space-time appears as wave traveling in an inhomogeneous effective bi-anisotropic medium , Its constitutive parameters are determined by space-time metrics.

This can express the inverse problem of transforming from a flat space-time medium to a certain curvilinear space-time, and find specific conditions for invisibility cloaking.

The above-described prior arts are limited to the transparency technique in which the object of concealment is limited to electromagnetic waves, and prior art in which an object of concealment is defined as an acoustic wave has not yet been specified.

Korean Patent Laid-Open Publication No. 10-2013-0047860 (Publication date 2013.05.09)

Doyeol Ahn, Journal of Modern Optics, Volume 58, Issue 8, 2011 (Publication date 2011.04.01) "Calculation of permittivity tensors for invisibility devices by effective medium approach in general relativity" "Complementary media invisibility cloak that cloaks objects at a distance outside the cloaking shell," Y. Lai, H. Chen, Z. Q. Zhang, and C. Chan, Phys. Rev. Lett. 102,93901 (2009). (Public date 2009.03.02)

Disclosure of Invention Technical Problem [8] The present invention has been made to solve the problems of the prior art as described above, and it is an object of the present invention to provide a method and apparatus for blocking a specific region from a sound wave using a meta-material, And to provide a sound wave concealment method and apparatus therefor.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method and apparatus for concealing a sound wave that can be handled even when the sound wave concealing target region has various geometric shapes.

It is an object of the present invention to provide a method and an apparatus capable of concealing a specific region from a sound wave irrespective of factors such as the frequency or the speed of the sound wave.

In order to achieve the above object, a sound concealment method according to an embodiment of the present invention is a method for concealing a sound wave based on a predetermined acoustic wave transfer mathematical model for sound wave transmission and a correlation of a predetermined electromagnetic wave mathematical model with respect to the electromagnetic wave, Converting the model into an acoustic concealment mathematical model corresponding to the electromagnetic wave mathematical model; Deriving a target characteristic of the meta-material using the transformed acoustic concealment mathematical model; And disposing the meta-material having the target characteristic derived to surround the region including the object, thereby blocking the region from sound waves.

Wherein the electromagnetic wave mathematical model includes a mathematical model of a Maxwell equation and the step of converting to an acoustic concealment mathematical model comprises substituting the sound wave transfer mathematical model into a relativistic coordinate space modification method based on the Maxwell equation, It can be converted into the sound wave concealment mathematical model.

The mathematical model of the Maxwell's equation may be a mathematical model of the Maxwell's equation for the elliptical coordinate system or a mathematical model of the Maxwell's equation for the bipolar coordinate system.

Converting the sound wave concealment mathematical model to the electromagnetic wave mathematical model based on a one-to-one correspondence between each term of the acoustic wave transfer mathematical model and each term of the electromagnetic wave mathematical model with respect to the two- Can be converted to the corresponding acoustic concealment mathematical model.

A sound wave concealment apparatus according to an embodiment of the present invention is a sound wave concealment apparatus for blocking a sound wave using a meta-material, wherein the meta-material has a target characteristic derived using a predetermined acoustic hiding mathematical model, Wherein the acoustic hiding mathematical model is arranged to surround an area containing an object to be subjected to acoustic wave mathematical modeling based on a correlation of a predetermined electromagnetic wave mathematical model with a predetermined acoustic wave transfer mathematical model for acoustic wave propagation, Is converted and determined from the sound wave transfer mathematical model so as to correspond thereto.

Wherein the electromagnetic wave mathematical model comprises a mathematical model of a Maxwell equation and the acoustic hiding mathematical model is transformed from the sound wave transfer mathematical model by substituting the sound wave transfer mathematical model into a relativistic coordinate space transform method based on the Maxwell equation have.

According to the present invention, a meta-material having a target characteristic derived by substituting a mathematical model for sound wave propagation into a relativistic coordinate space transformation method based on Maxwell's equation is used to block a specific region from a sound wave, Can be prevented from being transmitted to the outside.

In addition, according to the present invention, it is possible to isolate a noise source from a sound wave because the object or a specific area can be blocked from a sound wave, sound waves can be cut off to a desired area, The present invention is applicable to the reduction of the noise level in principle.

According to the present invention, even when the sound wave concealment target area has various geometric shapes such as an elliptic cylindrical shape and a bipolar cylindrical shape, the characteristics of a meta material capable of concealing sound waves can be derived.

According to the present invention, it is possible to derive the property of a meta-material that can conceal a specific region from a sound wave irrespective of factors such as frequency and speed of a sound wave.

FIG. 1 shows an example of a transparent cloak based on a method for analyzing a space-time meta-material based on general relativity.
2 is a flowchart illustrating an operation of a sound concealment method according to an embodiment of the present invention.
FIG. 3 illustrates a configuration of an acoustic wave concealment apparatus for an elliptical coordinate system according to an embodiment of the present invention.
4 shows the result of cloaking for the sound wave concealment device of FIG.
FIG. 5 shows a configuration of a sound wave concealing apparatus for a bipolar coordinate system according to an embodiment of the present invention.
6 shows a result of cloaking for the sound wave concealment apparatus of FIG.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the accompanying drawings.

Preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

However, the present invention is not limited to or limited by the embodiments. Like reference symbols in the drawings denote like elements.

Hereinafter, a method and a device for concealing a sound wave according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 6 attached hereto.

In this specification, a meta material is defined as follows. A metamaterial is used to mean a material that can artificially control or design the tensor of permittivity and permeability, or to be used as a material obtained as a result of its control or design.

When the Maxwell equations are formulated in a space-time with a finite curvature, the transparency device is based on the theoretical argument that the curvature of space-time acts as permittivity and permeability for electric and magnetic fields. do.

Specifically, the covariant Maxwell equation in general relativity theory can be expressed as Equation (1) below.

[Equation 1]

Where ε ₀ is the permittivity in free space, μ, ν, and λ represent the permittivity of each component in the 4-dimensional coordinate space component.

g denotes a determinant of a metric tensor g _占 ., J denotes a current density, and F _{占 를} denotes an electromagnetic field tensor.

The above equation (1) can be expressed in Korean Patent Laid-Open Publication No. 10-2013-0047860 (published on May 31, 2013) and "Calculation of permittivity tensors for invisibility devices by effective medium approach in general relativity", Doyeol Ahn, Journal of Modern Optics , Volume 58, Issue 8, 2011 (Published on April 21, 2011). Also, a derivation process for a plurality of equations derived from the following is also introduced in the prior art. Therefore, the present invention will be described in detail in the context of the present invention, without departing from the scope of the present invention.

At this time, the electromagnetic field tensor can be expressed by Equation (2) below. Electromagnetic tensors are described in the form of matrices for three dimensions of zero dimension (time) and space in general relativity theory.

&Quot; (2) "

Here, E means electric field, x, y, z means direction, and B means electric flux.

The contra-variant tensor H ^μν can be expressed by Equation (3) below, and Equation (3) can be defined as Equation (4) below.

&Quot; (3) "

&Quot; (4) "

Here, H denotes a magnetic field and D denotes a magnetic flux.

The above equations can be summarized as the following equations (5) and (6).

&Quot; (5) "

&Quot; (6) "

Here, [ijk] is an anti-symmetric permutation symbols (anti-symmetric permutation symbol), as defined in [xyz] = 1, μ ₀ denotes the permeability of free space, and g ^ab is the banbyeon metric tensor (a , b) component, and g _cd means (c, d) component of the covariance matrix tensor.

As can be seen from the above equation, it can be seen that the Maxwell's equation in a vacuum having a finite radius of curvature can be interpreted as a Maxwell's equation in a medium having a finite permittivity and transmittance.

FIG. 1 shows an example of a transparent cloak based on a method of analysis of space-time meta-materials based on general relativity. In the physical space, the middle empty space means a space for hiding a given object.

^' _ij로 정의하면 두 공간 사이의 변환식은 아래 <수학식 7>로 주어지며 메타 물질로 구현할 물리적 공간의 유전율 텐서(ε^ij)와 투과율 텐서(μ^ij)는 아래 <수학식 8>과 같이 표현될 수 있다.The virtual space means a space in which an empty space of the physical space is converted into a central point. Using this relationship, we can create an intuitive picture of transparent cloak using coordinate transformations between the physical space and the virtual space to realize the actual invisibility cloaking, and between the two space-time. The coordinate transformation between these two spaces can be described by a space time metric tensor ( _gμν ), and a metric tensor representing the curvilinear coordinates of the physical space

^' _ij , the conversion equation between the two spaces is given by Equation (7), and the permittivity tensor (ε ^ij ) and the permeability tensor (μ ^ij ) of the physical space to be implemented by the meta-material are expressed by Equation .

&Quot; (7) &quot;

&Quot; (8) &quot;

는

_ij를 의미하고,

^kk는 1/

_kk를 의미한다.here,

The

_ij means,

^kk is 1 /

_respectively .

However, the transparent cape implemented in this way has a disadvantage that the efficiency of transparency is maximized when the electromagnetic wave is polarized in a specific direction.

The present invention is based on papers already published by the inventors of the present invention [J. Mod. Opt. (JOSA B 30, 140-148 (2013)], and in the inventor's paper, we use the transparent cloak of electromagnetic wave A mathematical model for blocking a sound wave from a mathematical model of sound wave propagation or making a sound wave transparent by using a relativistic coordinate space transformation method based on a Maxwell equation used to implement a sound wave and deriving a sound wave concealment mathematical model, By deriving the target characteristics of the meta-material, it is necessary to make the specific region transparent from the sound wave or block the sound wave to the specific region.

2 is a flowchart illustrating an operation of a sound concealment method according to an embodiment of the present invention

Referring to FIG. 2, the method according to the present invention corresponds to a mathematical model of sound wave transmission for sound wave propagation and an electromagnetic wave mathematical model for electromagnetic wave, and a mathematical model of sound wave propagation based on the correlation between the sound wave transmission mathematical model and the electromagnetic wave mathematical model (S210, S220) into an acoustic concealment mathematical model corresponding to the electromagnetic wave mathematical model.

Here, the electromagnetic wave mathematical model may be a mathematical model of a Maxwell equation, a mathematical model of a Maxwell equation for an elliptical coordinate system or a mathematical model of a Maxwell equation for a bipolar coordinate system, and a sound wave concealment mathematical model may include a relative- Can be transformed from a sound wave transfer mathematical model by substituting a sound wave transfer mathematical model for the spatial deformation method.

The sound wave equation for the acoustic wave transfer mathematical model can be expressed as Equation (9) below.

&Quot; (9) &quot;

는 유체의 속도 벡터를 의미하고, ρ는 유체 또는 매질의 질량을 의미하고, λ는 유체 또는 매질의 체적 탄성률(bulk modulus)을 의미한다.Here, p means pressure,

Denotes the velocity vector of the fluid, ρ denotes the mass of the fluid or medium, and λ denotes the bulk modulus of the fluid or medium.

The acoustic wave equation has a one-to-one correspondence with the Maxwell equation, which is an electromagnetic wave mathematical model, and the specific polarized light in the two-dimensional case. Based on this correlation, a transparent cloak method concerning the electromagnetic wave can be used.

The sound wave equation can be expressed as Equation (10) with respect to generalized curvilinear coordinates q ₁ , q ₂ , and q ₃ .

&Quot; (10) &quot;

_i는 q_i축 방향의 단위벡터(i=1,2,3)를 의미하고, h_i는 q_i축 상의 두 점간의 거리를 나타내기 위한 메트릭을 의미한다.here

_i denotes a unit vector in the q _i axis direction (i = 1, 2, 3), and h _i denotes a metric for expressing the distance between two points on the q _i axis.

인 경우를 생각할 수 있으며, 특히 시간 하모닉(time-harmonic)인 경우 음파 방정식은 아래 <수학식 11>과 같이 나타낼 수 있다.Assuming, for convenience, symmetry about the z-axis in two dimensions, q ₃ = z, h ₃ = 1 and

In particular, in the case of time-harmonic, the sound wave equation can be expressed as Equation (11) below.

&Quot; (11) &quot;

에 대해 아래 <수학식 13>과 같이 나타낼 수 있다.The Maxwell equation for the electromagnetic field can be expressed as Equation (12) below, and a general vector field

Can be expressed as Equation (13) below.

&Quot; (12) &quot;

&Quot; (13) &quot;

Equation (14) can be obtained from Equation (12) and Equation (13) when a time harmonic is applied to a TE (transverse electric) wave (H ₁ , H ₂ , E _z ).

&Quot; (14) &quot;

When Equations (11) and (14) are compared, when the variables for the sound wave equation and the parameters for the electromagnetic wave equation have the one-to-one correspondence relationship as shown below in Equation (15) .

&Quot; (15) &quot;

The mathematical model of the sound wave can be converted into the acoustic concealment mathematical model corresponding to the electromagnetic wave mathematical model using the relational expression of Equation (15).

Thus, the present invention is not limited to the papers already published by the inventors of the present invention [J. Mod. Opt. 58, 700-710 (2011), Journal of the Korean Physical Society 60, 1349-1360 (2012), JOSA B 30, 140-148 (2013), JOSA B 30, 2148 (2013) , The sound wave can be blocked by substituting the mathematical model of sound wave transfer into the relativistic coordinate space variation method of the Maxwell equation period.

Referring again to FIG. 2, a target characteristic of a meta-material is derived using an acoustic concealment mathematical model converted from a sound wave transfer mathematical model by substituting a sound wave transfer mathematical model into a relativistic coordinate space modification method based on Maxwell's equation (S230 ).

Here, the target characteristic of the meta-material may include the density of the fluid or the mass of the medium, the volume elastic modulus of the fluid or medium, and the like.

By disposing the meta-material having the target characteristic derived by the step S230 so as to surround the area including the object, the sound wave is blocked by using the meta-material and thus the sound wave proceeding to the area including the object is blocked, It is possible to prevent the sound waves generated from the area including the object from going out to the outside (S240, S250).

The object to be used in the present invention may be a spatial concept or an object corresponding to a noise source.

As described above, in the sound concealment method according to the present invention, a mathematical model of a sound wave is substituted into a relativistic coordinate space deformation method based on Maxwell's equation, a sound wave transfer mathematical model is converted into an acoustic concealment mathematical model, and a converted sound concealment mathematical model is used By deriving the target characteristics of the meta-material, it is possible to block the sound waves using the meta-material having the derived target characteristics.

In the present invention, a sound wave concealment apparatus of an elliptical coordinate system and a bipolar coordinate system will be described as an example.

1) The sound wave concealment device of the elliptic coordinate system

FIG. 3 shows an example of a sound wave concealment apparatus using an elliptic cylindrical coordinate system. The relationship between the independent variable (u, v, z) of the elliptic coordinate system and the rectangular coordinate system (x, y, z) (16) < / RTI >

&Quot; (16) &quot;

Here, (a, 0) and (-a, 0) shown in FIG. 3 indicate focus in the elliptic coordinate system.

3, when the area to be protected is u < U ₁ and the meta-material 310 constituting the transparentizing device is U ₁ < u < U ₂ And using primed coordinates for empty curve space and time, the physical medium can be defined as Equation (17) below.

At this time, the coordinate system used may be a generalized cylindrical coordinate system.

&Quot; (17) &quot;

Here, U ₁ and U ₂ are predetermined values of a region made of a meta-material, u 'means a distance in a virtual space, u means a distance in a physical space, and v' Refers to the generalized angle or distance of the physical space, v denotes the generalized angle or distance in physical space, and z and z 'denote the distance (height) in physical space and z direction in virtual space.

Also, permittivity and permeability for realizing the elliptical cylindrical transparent cape from the effective medium approach in the general relativity theory can be expressed as Equation (18) below.

&Quot; (18) &quot;

Here, diag () denotes a diagonal matrix, and ε ⁱ _j and μ ⁱ _j can _denote permittivity tensor and permeability tensor in an elliptic cylindrical coordinate system.

Through the above Equations (15) and (18), the condition for implementing the sound wave concealment method or apparatus in the elliptic coordinate system is expressed as Equation (19) below.

&Quot; (19) &quot;

That is, as can be seen from Equation (19), it can be seen that the target characteristic for the meta-material in the elliptical coordinate system can be derived using the acoustic concealment mathematical model converted from the sound wave transfer mathematical model.

By arranging the meta-material having the target characteristic derived using Equation (19) so as to surround the target region, the target region can be protected from the sound wave.

As can be seen from the numerical analysis results shown in FIGS. 4A and 4B, the sound wave concealment method or apparatus for the elliptical coordinate system is such that a sound wave or a pressure wave traveling in the x- and y-axis directions does not reach the inner region of the elliptic cylinder Therefore, the present invention can be applied not only to isolation of a noise source but also to a source of sound waves in a desired area, and to reduce the noise level of an apartment building and noise level of a ship or a submarine.

2) Bipolar coordinate sound wave concealment device

FIG. 5 shows an example of a bipolar cylindrical coordinate system. The relationship between the independent variables (σ, τ, z) of the bipolar coordinate system and the rectangular coordinate system (x, y, z) (20) < / RTI >

&Quot; (20) &quot;

이고, τ의 범위는

이고, z의 범위는

일 수 있다.Where σ denotes the angle in the physical space or the generalized distance, τ denotes the ratio of the distance to the angle σ at any point P of the bipolar cylindrical coordinate system in the physical space, and the range of σ

, And the range of τ is

, And the range of z is

Lt; / RTI &gt;

In the case of a bipolar cylindrical cloak, the region or object region to which the object to be transparent belongs can be represented using a bipolar cylindrical coordinate system.

영역에 배치될 수 있다. 여기서, σ는 물리적 공간에서의 각도 또는 일반화된 거리를 의미하고, σ₁과 σ₂는 물리적 공간에서 미리 결정된 각도 또는 일반화된 거리를 의미한다.At this time, the object or object area to be protected is disposed at? ₁ <? <2? -? ₁ , and the meta material 510 constituting the transparency

Region. &Lt; / RTI &gt; Here,? Refers to an angle or a generalized distance in physical space, and? ₁ and? ₂ mean a predetermined angle or a generalized distance in physical space.

Therefore, the map of the bipolar cylindrical coordinate system can be defined by Equation (21) below.

&Quot; (21) &quot;

Here, σ 'denotes an angle in virtual space, σ denotes an angle in physical space, and τ and τ' denote angles σ and σ 'at any point P of the bipolar cylindrical coordinate system in physical space and virtual space to mean the ratio of the distance (d _1, d ₂₎ of the ', this is for information about the person of ordinary skill in the art bipolar coordinate system to engage in the art (https:.. // en wikipedia org / wiki / bipolar _ coordinates Etc.) and the relationship between the virtual space and the physical space in Fig. 1 can be easily understood.

Thus, the configuration parameters for the bipolar cylindrical transparency device or transparent cloak can be obtained as: < EMI ID = 22.0 >

&Quot; (22) &quot;

Where ε ⁱ _j and μ ⁱ _j are the permittivity tensor and the permeability tensor in a bipolar cylindrical coordinate system.

Through the above Equations (15) and (22), the condition for implementing the sound wave concealment method or apparatus in the elliptic coordinate system is expressed as Equation (23) below.

&Quot; (23) &quot;

That is, as can be seen from Equation (23), it can be seen that the target characteristic for the meta-material in the bipolar coordinate system can be derived by using the acoustic concealment mathematical model converted from the sound wave transfer mathematical model.

By arranging the meta-material having the target characteristic derived using Equation (23) so as to surround the target region, the target region can be protected from the sound wave.

As can be seen from the numerical analysis results shown in FIGS. 6A and 6B, the acoustic wave concealment method or apparatus for the bipolar coordinate system is a method in which a sound wave or a pressure wave traveling in the x- and y-axis directions does not reach the inner region of the bipolar cylinder Therefore, the present invention can be applied not only to isolation of a noise source but also to a source of sound waves in a desired area, and to reduce the noise level of an apartment building and noise level of a ship or a submarine.

As described above, the present invention has been described with reference to particular embodiments, such as specific elements, and specific embodiments and drawings. However, it should be understood that the present invention is not limited to the above- And various modifications and changes may be made thereto by those skilled in the art to which the present invention pertains.

Accordingly, the spirit of the present invention should not be construed as being limited to the embodiments described, and all of the equivalents or equivalents of the claims, as well as the following claims, belong to the scope of the present invention .

Claims (8)

Converting the sound wave transfer mathematical model into a sound wave concealment mathematical model corresponding to the electromagnetic wave mathematical model based on a correlation between a predetermined sound wave transfer mathematical model for the sound wave transfer and a predetermined electromagnetic wave mathematical model for the electromagnetic wave;
Deriving a target characteristic of the meta-material using the transformed acoustic concealment mathematical model; And
Disposing the meta-material having the derived target characteristic so as to surround the region including the object, and blocking the region from the sound wave
And a sound wave concealment method. The method according to claim 1,
The electromagnetic wave mathematical model
Including mathematical models of Maxwell's equations,
The step of converting to the acoustic concealment mathematical model
And converting the sound wave transfer mathematical model into the sound wave concealment mathematical model by substituting the sound wave transfer mathematical model into the relativistic coordinate space modification method based on the Maxwell equation. 3. The method of claim 2,
The mathematical model of the Maxwell equation
A mathematical model of a Maxwell's equation for an elliptical coordinate system or a mathematical model of a Maxwell's equation for a bipolar coordinate system. The method according to claim 1,
The step of converting to the acoustic concealment mathematical model
Converting the acoustic wave transfer mathematical model to the acoustic mathematical model corresponding to the electromagnetic wave mathematical model based on a one-to-one correspondence between each term of the acoustic wave mathematical model and each term of the electromagnetic wave mathematical model for two-dimensional coordinates Wherein the sound wave concealment method comprises the steps of: 1. A sound concealment apparatus for blocking a sound wave using a meta-material,
The meta-
A target acoustic wave model having a target characteristic derived by using a predetermined acoustic wave hiding mathematical model and arranged to surround an area including a target object for blocking a sound wave,
The acoustic concealment mathematical model
Is determined and converted from the sound wave transfer mathematical model to correspond to the electromagnetic wave mathematical model based on a correlation between a predetermined sound wave transfer mathematical model for the sound wave transfer and a predetermined electromagnetic wave mathematical model for the electromagnetic wave
And the sound wave shielding device. 6. The method of claim 5,
The electromagnetic wave mathematical model
Including mathematical models of Maxwell's equations,
The acoustic concealment mathematical model
Wherein the sound wave transfer mathematical model is transformed from the sound wave transfer mathematical model by substituting the sound wave transfer mathematical model into a relativistic coordinate space modification method based on the Maxwell equation. The method according to claim 6,
The mathematical model of the Maxwell equation
A mathematical model of a Maxwell's equation for an elliptical coordinate system, or a mathematical model of a Maxwell's equation for a bipolar coordinate system. The method according to claim 6,
The acoustic concealment mathematical model
Dimensional mathematical model corresponding to the electromagnetic wave mathematical model based on a one-to-one correspondence relationship between each term of the acoustic wave mathematical model and each term of the electromagnetic wave mathematical model with respect to the two-dimensional coordinate. Sound wave concealment device.

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