Acoustic material having ultra-wideband acoustic extraordinary reflection function
What is Al technical title?
Al technical title is built by PatSnap Al team. It summarizes the technical point description of the patent document.
An acoustic material and ultra-broadband technology, applied in the direction of sound-generating devices, instruments, etc., can solve problems such as complex structure and large volume
Inactive Publication Date: 2015-09-16
NANJING UNIV
View PDF1 Cites 11 Cited by
Summary
Abstract
Description
Claims
Application Information
AI Technical Summary
This helps you quickly interpret patents by identifying the three key elements:
Problems solved by technology
Method used
Benefits of technology
Problems solved by technology
[0004] The purpose of the present invention is to provide an acoustic material with a simple structure for the acoustic mat
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more
Image
Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
Click on the blue label to locate the original text in one second.
Reading with bidirectional positioning of images and text.
Smart Image
Examples
Experimental program
Comparison scheme
Effect test
Embodiment 1
[0049] Example 1: Sound Wave Redirection
[0050] see figure 2 , image 3 and Figure 4 Shown is a metasurface that produces a 45-degree reflection at normal incidence. At this time, the surface phase profile should satisfy a linear change. According to the concept of the generalized reflection law, the abnormal reflection angle is:
[0051] θ r = arcsin [ sin ( θ i ) + λ 2 π dφ dx ]
[0052] The abnormal reflection angle θ can be obtained r The relationship with the gradient g(x) of the groove depth change is:
[0053] θ r =arcsin[sin(θ i )+2g(x)]
[0054] Note that the reflection angle in Equation 3 has nothing to do with wavelength, therefore, the proposed mechanism can eliminate the depende...
Embodiment 2
[0056] Embodiment 2: Acoustic focusing:
[0057] see Figure 5 , Figure 6 and Figure 7 As shown, the numerical simulation results of acoustic wave focusing are shown, and the phase profile of the surface satisfies:
[0058] φ ( x ) = k 0 [ ( x - x 0 ) 2 + y 0 2 - x 0 2 + y 0 2 ]
[0059] Then the groove depth distribution is:
[0060] h ( x ) ...
Embodiment 3
[0062] Example 3: Curved sound field
[0063] see Figure 8 , Figure 9 and Figure 10 As shown, it shows the numerical simulation results of the bending sound field at three frequencies (7277Hz, 12128Hz, 16979Hz) under the condition of normal incidence of sound waves (the width of the groove in the sample is d=0.75cm, and the thickness of the groove wall is d 0 =0.25cm), the dotted line is the designed curved route, the curved sound field can be produced by the following phase profile:
[0064] φ ( x ) = k 0 [ ( x + r ) 2 - r 2 - r ( r x + r ...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more
PUM
Login to view more
Abstract
The invention discloses an acoustic material having an ultra-wideband acoustic extraordinary reflection function. A surface of the acoustic material is provided with different-depth grooves which are successively arranged; the widths d of the grooves are the same, wherein [lambda]>2d, and [lambda] is the wavelength of a sound wave; distances between the adjacent grooves are d<0>, wherein d>=3d<0>; and an x axis is established, and the x axis is parallel to the surface and is perpendicular to the grooves, wherein depths of the grooves are h(x) and are represented by the formula h(x). The acoustic material having the ultra-wideband acoustic extraordinary reflection function only needs incidence of one sound source and then can achieve ultra-wideband wavefront control, a traditional loudspeaker array is replaced, and a single-frequency limit of an acoustic super surface is broken through. The acoustic material can be applied to ultrasonic therapy, noise control or some special sound wave manipulation occasions.
Description
technical field [0001] The invention relates to an acoustic material with ultra-broadband acoustic supernormal reflection. Background technique [0002] Phased array technology is a commonly used technology in acoustics. Usually, loudspeaker sequences with different phases are used to form a phase profile, and the sound wave interference effect is used to achieve various functions, such as sound wave redirection, sound wave focusing, or curved sound field. And some passive methods such as acoustic metasurfaces can only work at a single frequency or narrow bandwidth. [0003] Therefore, a new acoustic material with ultra-broadband acoustic super-reflection is needed to solve the above problems. Contents of the invention [0004] The object of the present invention is to provide an acoustic material with ultra-broadband acoustic super-reflection with a simple structure, aiming at the defects of large volume and complex structure in the prior art. [0005] In order to achie...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more
Application Information
Patent Timeline
Application Date:The date an application was filed.
Publication Date:The date a patent or application was officially published.
First Publication Date:The earliest publication date of a patent with the same application number.
Issue Date:Publication date of the patent grant document.
PCT Entry Date:The Entry date of PCT National Phase.
Estimated Expiry Date:The statutory expiry date of a patent right according to the Patent Law, and it is the longest term of protection that the patent right can achieve without the termination of the patent right due to other reasons(Term extension factor has been taken into account ).
Invalid Date:Actual expiry date is based on effective date or publication date of legal transaction data of invalid patent.
Login to view more 
Login to view more