Approximate Results of Acoustic Impedance for a Cosine-Shaped Horn

Arenas, Jorge P.; Crocker, Malcolm J.

doi:10.1006/jsvi.2000.3062

Cited by 10 publications

(12 citation statements)

References 17 publications

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“…15,16 The numerical values were calculated with the boundary element method (BEM) using Virtual.Lab.Acoustics, in which the air is set as a homogeneous medium with density and velocity of the sound. The boundary condition of velocity is exerted at the center of the tube's bottom in a circular area with radius same as the diaphragm of the loudspeaker used in the tests.…”

Section: Application Of the Probes In The Pipe And Hornmentioning

confidence: 99%

“…[10][11][12][13] However, the experimental method was not be affected by this, but it also had the potential to give precise values of the radiation resistance in a frequency ranges. Arenas et al [14][15][16] has studied the experimental method of measuring the acoustic radiation resistance with good results obtained. Even though some studies have been conducted, [14][15][16][17][18][19] such as the there is no other research work on the accuracy of the experimental results and the optimal size of the experimental device with its applicable frequency range.…”

Section: Introductionmentioning

confidence: 99%

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Probes Design and Experimental Measurement of Acoustic Radiation Resistance

Wang¹,

Xiang²

2017

IJAV

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An experimental method used to measure radiation resistance was developed, which was based on a lumped parameter model. Three probes (devices for measuring acoustical radiation resistance) were designed, and the test system was built. To verify the accuracy of the experimental results and to find the application frequencies range for each of the probes, self-resistance and cross-resistance measurements of baffled circular pistons were conducted. The results show that this method is a practical way to obtain the acoustical resistance and that the probe with a 57 mm speaker can obtain resistance values in the frequency range from 260 Hz to 1700 Hz. The probe with a 50 mm speaker, on the other hand, presents resistance in the frequency range from 460 Hz to 1900 Hz; the range of 700 Hz to 2600 Hz is for the probe with a 40 mm loudspeaker. To verify the actual application effects, experiments measuring the resistance of a horn were performed. The results show that the measuring system with three probes can be used to predict acoustical resistance of various structures with high accuracy in a convenient and simple way.

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Section: Application Of the Probes In The Pipe And Hornmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Probes Design and Experimental Measurement of Acoustic Radiation Resistance

Wang¹,

Xiang²

2017

IJAV

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“…Due to the influence of the mass density law and the stiffness law, large material thickness is generally required to achieve the sound absorption in low-frequency region for traditional sound-absorbing materials such as microperforated sound absorbers and porous fiber materials. [1][2][3][4][5] Furthermore, the sound-absorption effect will not improve when the material thickness increases to a certain extent. As a result, the traditional sound-absorption structures have great limitations in practical engineering application because of its large thickness.…”

Section: Introductionmentioning

confidence: 99%

A Compact Tunable Broadband Acoustic Metastructure with Continuous Gradient Spiral Channels

Liang

et al. 2023

Adv Eng Mater

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Sound‐absorbing structures, an effective measure to reduce vibration and noise, have always been the desirable research hotspot in scientific and engineering communities. However, the mutual restriction between ultrathin thickness and broadband sound absorption is the key issue that hinders its development. Herein, a compact tunable broadband acoustic metastructure with continuous gradient spiral channels is presented, which has the ultrathin thickness and can efficiently realize low‐frequency broadband sound absorption. Coiled‐up individual absorbers are introduced to constitute the acoustic metastructure. The continuous gradient spiral channels are formed by successively decreasing the effective spiral length of labyrinthine cavity to achieve efficient broadband sound absorption. It is showed in the results that the sound‐absorption metastructure coupled with eight individual absorbers maintains the excellent broadband sound‐absorption effect over 0.8 in the frequency range of 487–930 Hz and a deep subwavelength thickness of 37 mm. In addition, the highly efficient low‐frequency broadband sound absorption can be implemented in the target range of 480–990 Hz through optimizing the adjustable parameters such as the effective spiral length, cross‐section height, orifice radius, and the coupling number of single absorbers. Herein, inspirations and threads are provided for the compact tunable broadband sound‐absorption design of acoustic metastructures.

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“…[3] Sound absorption is a commonly used noise attenuation strategy, which is used extensively for sound field control in various enclosed or semi-enclosed spaces. [4,5] Widely used sound-absorbing materials include porous fiber materials, [6,7] porous foam materials, [8,9] or structures such as micro-perforated plate absorbers, [10,11] can directly transform sound into viscosity thermal or elastic strain energy for dissipation. However, porous sound absorbing materials not only cannot bear the load, but also need a thick layer to absorb low-frequency sound waves.…”

Section: Introductionmentioning

confidence: 99%

Ultrathin Space‐Shift Phase‐Coherent Cancellation Metasurface for Broadband Sound Absorption

Ma,

Zhang,

Wang

et al. 2023

Small Methods

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A space‐shift phase‐coherent cancellation acoustic metasurface is developed, which can achieve broadband low‐frequency sound absorption via ultra‐thin integrated structure composed of multiple units with weak absorption capability. Through a space‐shift design of the channel length, the large‐size required in the thickness direction for low‐frequency absorption is transferred into an extremely ultra‐thin space layer. The units with gradient channel length are compactly arranged in an ultra‐thin layer through space folding, a coplanar sound absorption metasurface component with working bandwidth exceeding an octave and thickness of only λ/25 to λ/57 is obtained. As the construction of a special double‐hole “bridge” layout, even if the elements are sparsely distributed, strong coupling interactions between the units can sustain. When a certain local phase relationship is satisfied, the coherent cancellation of sound energy can be achieved, so as to reduce the sound reflection and scattering, and enhance the absorption performance. Therefore, from the perspective of phase relationship among units, the present work provides more clear physical image and intuitive theoretical explanation for achieving excellent broadband sound absorption through parallel superposition of multiple units with weak absorption capability. The proposed ultra‐thin sound absorbing metasurface can satisfy the thickness limitations and absorption performance requirements in most equipment.

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Approximate Results of Acoustic Impedance for a Cosine-Shaped Horn

Cited by 10 publications

References 17 publications

Probes Design and Experimental Measurement of Acoustic Radiation Resistance

Probes Design and Experimental Measurement of Acoustic Radiation Resistance

A Compact Tunable Broadband Acoustic Metastructure with Continuous Gradient Spiral Channels

Ultrathin Space‐Shift Phase‐Coherent Cancellation Metasurface for Broadband Sound Absorption

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