The Experts below are selected from a list of 102927 Experts worldwide ranked by ideXlab platform
Xiaojun Liu - One of the best experts on this subject based on the ideXlab platform.
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broadband near perfect absorption of low Frequency Sound by subwavelength metasurface
Applied Physics Letters, 2019Co-Authors: Houyou Long, Ying Cheng, Xiaojun Liu, Chen Shao, Chen LiuAbstract:The emerging absorptive metasurface relies on arrays of structured meta-atoms with various geometries for customized Sound localization, which can significantly enhance the energy dissipation. However, most of the existing absorbers are for given frequencies at an optimal incident angle. This limitation on the working Frequency and incident angle remains a challenging obstacle for their practical applications, in addition to the perfect absorptance demand. Guided by the causality principle, a physical model is established in which the absorptive properties of such systems can be fully controlled by two simple parameters (i.e., leakage factor and loss factor) which are dictated by the geometrical properties of the underlying structures. We demonstrate a subwavelength metasurface absorber which shows near-perfect absorptance (at 95%) in a broad Frequency regime from 228 Hz to 319 Hz (wavelength λ from 12.6 to 9.0 times thickness) and even allows 93% reduction with a large incident angle of 60°. We prove that this broadband near-perfect absorption behavior stems from the tunable damping conditions, which can be achieved by coupling an ordinary ultrathin surface sponge coating with an artificial underdamped multiband absorptive system. From the view of the causality principle, the subwavelength near-perfect absorptions originate from the finite working bandwidth. As the research premise, we also demonstrate a λ/21.7-thick, 16.7%-filling ratio ultrasparse absorber with unity absorptance by modulating the displacements between uniformly sized coiled space resonators. The paradigm may pave the way for versatile devices in noise remediation engineering.
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multiband quasi perfect low Frequency Sound absorber based on double channel mie resonator
Applied Physics Letters, 2018Co-Authors: Houyou Long, Ying Cheng, Xiaojun Liu, Shuxiang GaoAbstract:Metamaterial absorbers have recently been developed to act as efficient Sound absorption components of subwavelength dimensions. However, the working Frequency has so far been mainly limited to a single narrow band. Here, we demonstrate a multiband quasi-perfect absorber constructed by a double-channel Mie resonator (DMR) in a unique configuration. By attentively tuning the leakage factor to match the loss factor at multi-order monopolar and dipolar resonances of DMR simultaneously, a series of absorptive peaks with near-unity absorptances have been achieved in both numerical simulation and the experimental measurement. Our approach gives a simple platform for extending the response of metamaterial devices from the single band to the multiband without superimposing resonant elements in multiple configurations, which allows us to envision acoustic devices with versatile applications.
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asymmetric absorber with multiband and broadband for low Frequency Sound
Applied Physics Letters, 2017Co-Authors: Houyou Long, Ying Cheng, Xiaojun LiuAbstract:We present the mechanism for the asymmetric absorption of acoustic waves in a two-port transparent waveguide system by shunting detuned Helmholtz resonators (HRs) pairs in cascade. Theoretical analysis, numerical simulations, and experimental measurements verify that Sound energy is almost totally absorbed (96.1%) at ∼373 Hz when Sound waves are incident from one side while it is largely reflected back from the opposite side by judiciously designed HRs to provide manipulated surface impedance matching/mismatching to that of air at the opposite sides of the waveguide. Thus, asymmetric acoustic absorber is achieved at a low Frequency. We have further demonstrated the flexibility of this methodology to get non-reciprocal absorption and reflectance in multiband and broadband. Our design advances the concept of asymmetric acoustic manipulation in passive two-port systems and may enable Sound-absorbing devices for more versatile applications.
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ultra sparse metasurface for high reflection of low Frequency Sound based on artificial mie resonances
Nature Materials, 2015Co-Authors: Yingchun Cheng, Chen Zhou, Baoguo Yuan, Qi Wei, Xiaojun LiuAbstract:Acoustic metamaterials offer great flexibility for manipulating Sound waves and promise unprecedented functionality, ranging from transformation acoustics, super-resolution imaging to acoustic cloaking. However, the design of acoustic metamaterials with exciting functionality remains challenging with traditional approaches using classic acoustic elements such as Helmholtz resonators and membranes. Here we demonstrate an ultraslow-fluid-like particle with intense artificial Mie resonances for low-Frequency airborne Sound. Eigenstate analysis and effective parameter retrieval show two individual negative bands in the single-size unit cell, one of which exhibits a negative bulk modulus supported by the monopolar Mie resonance, whereas the other exhibits a negative mass density induced by the dipolar Mie resonance. The unique single-negative nature is used to develop an ultra-sparse subwavelength metasurface with high reflectance for low-Frequency Sound. We demonstrate a 0.15λ-thick, 15%-filling ratio metasurface with an insertion loss over 93.4%. The designed Mie resonators provide diverse routes to construct novel acoustic devices with versatile applications.
Ying Cheng - One of the best experts on this subject based on the ideXlab platform.
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broadband near perfect absorption of low Frequency Sound by subwavelength metasurface
Applied Physics Letters, 2019Co-Authors: Houyou Long, Ying Cheng, Xiaojun Liu, Chen Shao, Chen LiuAbstract:The emerging absorptive metasurface relies on arrays of structured meta-atoms with various geometries for customized Sound localization, which can significantly enhance the energy dissipation. However, most of the existing absorbers are for given frequencies at an optimal incident angle. This limitation on the working Frequency and incident angle remains a challenging obstacle for their practical applications, in addition to the perfect absorptance demand. Guided by the causality principle, a physical model is established in which the absorptive properties of such systems can be fully controlled by two simple parameters (i.e., leakage factor and loss factor) which are dictated by the geometrical properties of the underlying structures. We demonstrate a subwavelength metasurface absorber which shows near-perfect absorptance (at 95%) in a broad Frequency regime from 228 Hz to 319 Hz (wavelength λ from 12.6 to 9.0 times thickness) and even allows 93% reduction with a large incident angle of 60°. We prove that this broadband near-perfect absorption behavior stems from the tunable damping conditions, which can be achieved by coupling an ordinary ultrathin surface sponge coating with an artificial underdamped multiband absorptive system. From the view of the causality principle, the subwavelength near-perfect absorptions originate from the finite working bandwidth. As the research premise, we also demonstrate a λ/21.7-thick, 16.7%-filling ratio ultrasparse absorber with unity absorptance by modulating the displacements between uniformly sized coiled space resonators. The paradigm may pave the way for versatile devices in noise remediation engineering.
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multiband quasi perfect low Frequency Sound absorber based on double channel mie resonator
Applied Physics Letters, 2018Co-Authors: Houyou Long, Ying Cheng, Xiaojun Liu, Shuxiang GaoAbstract:Metamaterial absorbers have recently been developed to act as efficient Sound absorption components of subwavelength dimensions. However, the working Frequency has so far been mainly limited to a single narrow band. Here, we demonstrate a multiband quasi-perfect absorber constructed by a double-channel Mie resonator (DMR) in a unique configuration. By attentively tuning the leakage factor to match the loss factor at multi-order monopolar and dipolar resonances of DMR simultaneously, a series of absorptive peaks with near-unity absorptances have been achieved in both numerical simulation and the experimental measurement. Our approach gives a simple platform for extending the response of metamaterial devices from the single band to the multiband without superimposing resonant elements in multiple configurations, which allows us to envision acoustic devices with versatile applications.
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asymmetric absorber with multiband and broadband for low Frequency Sound
Applied Physics Letters, 2017Co-Authors: Houyou Long, Ying Cheng, Xiaojun LiuAbstract:We present the mechanism for the asymmetric absorption of acoustic waves in a two-port transparent waveguide system by shunting detuned Helmholtz resonators (HRs) pairs in cascade. Theoretical analysis, numerical simulations, and experimental measurements verify that Sound energy is almost totally absorbed (96.1%) at ∼373 Hz when Sound waves are incident from one side while it is largely reflected back from the opposite side by judiciously designed HRs to provide manipulated surface impedance matching/mismatching to that of air at the opposite sides of the waveguide. Thus, asymmetric acoustic absorber is achieved at a low Frequency. We have further demonstrated the flexibility of this methodology to get non-reciprocal absorption and reflectance in multiband and broadband. Our design advances the concept of asymmetric acoustic manipulation in passive two-port systems and may enable Sound-absorbing devices for more versatile applications.
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perfect absorption of low Frequency Sound waves by critically coupled subwavelength resonant system
Applied Physics Letters, 2017Co-Authors: Houyou Long, Ying ChengAbstract:The perfect absorption (PA) for low-Frequency audible Sound waves has been achieved by critically coupling the inherent loss factor to the inherent leakage factor of a system, which is constructed by attaching a deep-subwavelength lossy resonant plate (LRP) to a backed rigid wall closely. We have certified it by using the graphical method in the complex Frequency plane. By coupling the LRP to an air cavity in front of the rigid wall, the high efficient (>80%) low-Frequency broadband absorption is obtained from 99.1 Hz to 294.8 Hz. Here, the thickness of LRP is only 1/13.5 of the relevant wavelength at 294.8 Hz. The impedance analyses further demonstrate that the impedances are perfectly matched between the system and the surrounding background medium at PA.
Han Meng - One of the best experts on this subject based on the ideXlab platform.
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small perforations in corrugated sandwich panel significantly enhance low Frequency Sound absorption and transmission loss
Composite Structures, 2017Co-Authors: Han Meng, Marieannick Galland, Mohamed Ichchou, O Bareille, F X XinAbstract:Abstract Numerical and experimental investigations are performed to evaluate the low Frequency Sound absorption coefficient (SAC) and Sound transmission loss (STL) of corrugated sandwich panels with different perforation configurations, including perforations in one of the face plates, in the corrugated core, and in both the face plate and the corrugated core. Finite element (FE) models are constructed with considerations of acoustic-structure interactions and viscous and thermal energy dissipations inside the perforations. The validity of FE calculations is checked against experimental measurements with the tested samples provided by additive manufacturing. Compared with the classical corrugated sandwich without perforation, the corrugated sandwich with perforated pores in one of its face plate not only exhibits a higher SAC at low frequencies but also a better STL as a consequence of the enlarged SAC. The influences of perforation diameter and perforation ratio on the vibroacoustic performance of the sandwich are also explored. For a corrugated sandwich with uniform perforations, the acoustical resonance frequencies and bandwidth in its SAC and STL curves decrease with increasing pore diameter and decreasing perforation ratio. Non-uniform perforation diameters and perforation ratios result in larger bandwidth and lower acoustical resonance frequencies relative to the case of uniform perforations. The proposed perforated sandwich panels with corrugated cores are attractive ultralightweight structures for multifunctional applications such as simultaneous load-bearing, energy absorption, Sound proofing and Sound absorption.
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hybrid acoustic metamaterial as super absorber for broadband low Frequency Sound
Scientific Reports, 2017Co-Authors: Yufan Tang, Han Meng, Shuwei Ren, Fengxian Xin, Lixi Huang, Tianning Chen, Chuanzeng ZhangAbstract:A hybrid acoustic metamaterial is proposed as a new class of Sound absorber, which exhibits superior broadband low-Frequency Sound absorption as well as excellent mechanical stiffness/strength. Based on the honeycomb-corrugation hybrid core (H-C hybrid core), we introduce perforations on both top facesheet and corrugation, forming perforated honeycomb-corrugation hybrid (PHCH) to gain super broadband low-Frequency Sound absorption. Applying the theory of micro-perforated panel (MPP), we establish a theoretical method to calculate the Sound absorption coefficient of this new kind of metamaterial. Perfect Sound absorption is found at just a few hundreds hertz with two-octave 0.5 absorption bandwidth. To verify this model, a finite element model is developed to calculate the absorption coefficient and analyze the viscous-thermal energy dissipation. It is found that viscous energy dissipation at perforation regions dominates the total energy consumed. This new kind of acoustic metamaterials show promising engineering applications, which can serve as multiple functional materials with extraordinary low-Frequency Sound absorption, excellent stiffness/strength and impact energy absorption.
Houyou Long - One of the best experts on this subject based on the ideXlab platform.
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broadband near perfect absorption of low Frequency Sound by subwavelength metasurface
Applied Physics Letters, 2019Co-Authors: Houyou Long, Ying Cheng, Xiaojun Liu, Chen Shao, Chen LiuAbstract:The emerging absorptive metasurface relies on arrays of structured meta-atoms with various geometries for customized Sound localization, which can significantly enhance the energy dissipation. However, most of the existing absorbers are for given frequencies at an optimal incident angle. This limitation on the working Frequency and incident angle remains a challenging obstacle for their practical applications, in addition to the perfect absorptance demand. Guided by the causality principle, a physical model is established in which the absorptive properties of such systems can be fully controlled by two simple parameters (i.e., leakage factor and loss factor) which are dictated by the geometrical properties of the underlying structures. We demonstrate a subwavelength metasurface absorber which shows near-perfect absorptance (at 95%) in a broad Frequency regime from 228 Hz to 319 Hz (wavelength λ from 12.6 to 9.0 times thickness) and even allows 93% reduction with a large incident angle of 60°. We prove that this broadband near-perfect absorption behavior stems from the tunable damping conditions, which can be achieved by coupling an ordinary ultrathin surface sponge coating with an artificial underdamped multiband absorptive system. From the view of the causality principle, the subwavelength near-perfect absorptions originate from the finite working bandwidth. As the research premise, we also demonstrate a λ/21.7-thick, 16.7%-filling ratio ultrasparse absorber with unity absorptance by modulating the displacements between uniformly sized coiled space resonators. The paradigm may pave the way for versatile devices in noise remediation engineering.
-
multiband quasi perfect low Frequency Sound absorber based on double channel mie resonator
Applied Physics Letters, 2018Co-Authors: Houyou Long, Ying Cheng, Xiaojun Liu, Shuxiang GaoAbstract:Metamaterial absorbers have recently been developed to act as efficient Sound absorption components of subwavelength dimensions. However, the working Frequency has so far been mainly limited to a single narrow band. Here, we demonstrate a multiband quasi-perfect absorber constructed by a double-channel Mie resonator (DMR) in a unique configuration. By attentively tuning the leakage factor to match the loss factor at multi-order monopolar and dipolar resonances of DMR simultaneously, a series of absorptive peaks with near-unity absorptances have been achieved in both numerical simulation and the experimental measurement. Our approach gives a simple platform for extending the response of metamaterial devices from the single band to the multiband without superimposing resonant elements in multiple configurations, which allows us to envision acoustic devices with versatile applications.
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asymmetric absorber with multiband and broadband for low Frequency Sound
Applied Physics Letters, 2017Co-Authors: Houyou Long, Ying Cheng, Xiaojun LiuAbstract:We present the mechanism for the asymmetric absorption of acoustic waves in a two-port transparent waveguide system by shunting detuned Helmholtz resonators (HRs) pairs in cascade. Theoretical analysis, numerical simulations, and experimental measurements verify that Sound energy is almost totally absorbed (96.1%) at ∼373 Hz when Sound waves are incident from one side while it is largely reflected back from the opposite side by judiciously designed HRs to provide manipulated surface impedance matching/mismatching to that of air at the opposite sides of the waveguide. Thus, asymmetric acoustic absorber is achieved at a low Frequency. We have further demonstrated the flexibility of this methodology to get non-reciprocal absorption and reflectance in multiband and broadband. Our design advances the concept of asymmetric acoustic manipulation in passive two-port systems and may enable Sound-absorbing devices for more versatile applications.
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perfect absorption of low Frequency Sound waves by critically coupled subwavelength resonant system
Applied Physics Letters, 2017Co-Authors: Houyou Long, Ying ChengAbstract:The perfect absorption (PA) for low-Frequency audible Sound waves has been achieved by critically coupling the inherent loss factor to the inherent leakage factor of a system, which is constructed by attaching a deep-subwavelength lossy resonant plate (LRP) to a backed rigid wall closely. We have certified it by using the graphical method in the complex Frequency plane. By coupling the LRP to an air cavity in front of the rigid wall, the high efficient (>80%) low-Frequency broadband absorption is obtained from 99.1 Hz to 294.8 Hz. Here, the thickness of LRP is only 1/13.5 of the relevant wavelength at 294.8 Hz. The impedance analyses further demonstrate that the impedances are perfectly matched between the system and the surrounding background medium at PA.
Jun Yang - One of the best experts on this subject based on the ideXlab platform.
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a low Frequency Sound absorbing material with subwavelength thickness
Applied Physics Letters, 2017Co-Authors: Changru Chen, Jun YangAbstract:We propose a Sound absorbing material efficient for low Frequency. This material is mainly composed of two axially coupled tubes in series, which are co-planarly coiled in a plane perpendicular to incident waves. By carefully designing the geometric parameters of the coupled tubes, we can overlap the absorption coefficient curves of each individual tube and are therefore able to broaden the Frequency bandwidth within which the absorption coefficient is larger than a designed value. A material with an absorption coefficient greater than 0.8 over a Frequency bandwidth of 36 Hz for a low Frequency of around 100 Hz can be designed, and the wavelength to thickness ratio reaches as high as 38.5. The experiment measurement with the sample made by the 3D printing technique is also conducted to validate the proposed design method. This work may stimulate the research studies on and applications for low Frequency Sound absorption.
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ultrathin low Frequency Sound absorbing panels based on coplanar spiral tubes or coplanar helmholtz resonators
Applied Physics Letters, 2014Co-Authors: Qiuquan Guo, Xiaobing Cai, Jun YangAbstract:Performance of classic Sound absorbing materials strictly depends on their thickness, with a minimum of one-quarter wavelength to reach full Sound absorption. In this paper, we report ultrathin Sound absorbing panels that completely absorb Sound energy with a thickness around one percent of wavelength. The strategy is to bend and coil up quarter-wavelength Sound damping tubes into 2D coplanar ones, and embed them into a matrix to form Sound absorbing panel. Samples have been designed and fabricated by 3D printing. Efficacies of Sound absorption by these panels were validated through good agreement between theoretical analysis and experimental measurements.
