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Related papers: Approximate Acoustic Cloaking in Inhomogeneous Iso…

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A general process is proposed to experimentally design anisotropic inhomogeneous metamaterials obtained through a change of coordinate in the Helmholtz equation. The method is applied to the case of a cylindrical transformation that allows…

Computational Physics · Physics 2019-04-15 Lucas Pomot , Cédric Payan , Marcel Remillieux , Sébastien Guenneau

Acoustic invisibility of a cloaking system in turbulent uids has been poorly understood. Here we show that evident scattering would appear in turbulent wakes owing to the submergence of a classical cloaking device. The inherent mechanism is…

Fluid Dynamics · Physics 2016-11-25 Xun Huang , Siyang Zhong

We propose a generalization of the two-dimensional eikonal-limit cloak derived from a conformal transformation to three dimensions. The proposed cloak is a spherical shell composed of only isotropic media; it operates in the transmission…

Optics · Physics 2012-03-28 Yaroslav Urzhumov , Nathan Landy , David R. Smith

Cloaks for underwater applications designed for actual submarine acoustic stealth are still far from the technological advancement needed for being put in practice. Several challenges are to be overcame such as dealing with weight or…

Classical Physics · Physics 2021-05-19 Davide Enrico Quadrelli , Gabriele Cazzulani , Simone La Riviera , Francesco Braghin

Transformation optics constructions have allowed the design of cloaking devices that steer electromagnetic, acoustic and quantum waves around a region without penetrating it, so that this region is hidden from external observations. The…

Analysis of PDEs · Mathematics 2015-09-15 Matti Lassas , Ting Zhou

This paper is concerned with the invisibility cloaking in electromagnetic wave scattering from a new perspective. We are especially interested in achieving the invisibility cloaking by completely regular and isotropic mediums. Our study is…

Mathematical Physics · Physics 2017-01-20 Jingzhi Li , Xiaofei Li , Hongyu Liu , Yuliang Wang

Hitherto acoustic cloaking devices, which conceal objects externally, have depended on the objects' characteristics. Despite previous works, we design cloaking device placed neighbor an arbitrary object and makes it invisible without the…

Applied Physics · Physics 2019-05-01 Zahra Basiri , Mohammad Hosein Fakheri , Ali Abdolali

Carpets under consideration here, in the context of pressure acoustic waves propagating in a compressible fluid, do not touch the ground: they levitate in mid-air (or float in mid-water), which leads to approximate cloaking for an object…

Optics · Physics 2010-05-19 Andre Diatta , Guillaume Dupont , Sebastien Guenneau , Stefan Enoch

Fundamental features of rotationally symmetric acoustic cloaks with anisotropic inertia are derived. Two universal relations are found to connect the radial and transverse phase speeds and the bulk modulus in the cloak. Perfect cloaking…

Fluid Dynamics · Physics 2008-02-07 Andrew N. Norris

This paper concerns the analysis of a passive, broadband approximate cloaking scheme for the Helmholtz equation in ${\mathbb R}^d$ for $d=2$ or $d=3$. Using ideas from transformation optics, we construct an approximate cloak by ``blowing…

Analysis of PDEs · Mathematics 2023-04-20 Fioralba Cakoni , Narek Hovsepyan , Michael Vogelius

The aim of this work is to derive sharp quantitative estimates of the qualitative convergence results developed in [28] for regularized full- and partial-cloaks via the transformation-optics approach. Let $\Gamma_0$ be a compact set in…

Analysis of PDEs · Mathematics 2015-08-20 Youjun Deng , Hongyu Liu , Gunther Uhlmann

Concealing objects by making them invisible to an external electromagnetic probe is coined by the term cloaking. Cloaking devices, having numerous potential applications, are still face challenges in realization, especially in the visible…

This paper is concerned with the analysis of time-harmonic electromagnetic scattering from plasmonic inclusions in the finite frequency regime beyond the quasi-static approximation. The electric permittivity and magnetic permeability in the…

Analysis of PDEs · Mathematics 2019-01-29 Hongjie Li , Shanqiang Li , Hongyu Liu , Xianchao Wang

Transformation Acoustics emerged in the mid-2000s, initiating a new paradigm of metamaterial designs. One of the most compelling designs, the invisibility cloak, holds promise for stealth and noise reduction applications in aviation.…

Applied Physics · Physics 2024-11-07 Levi T. Kaganowich , Deepak C. Akiwate , Trevor J. Cox , Olga Umnova

In this paper we propose and analyse a hybrid numerical-asymptotic boundary element method for the solution of problems of high frequency acoustic scattering by a class of sound-soft nonconvex polygons. The approximation space is enriched…

Numerical Analysis · Mathematics 2014-01-14 David P. Hewett , Simon N. Chandler-Wilde , Stephen Langdon , Ashley Twigger

Invisibility or unhearability cloaks have been made possible by using metamaterials making light or sound flow around obstacle without the trace of reflections or shadows. Metamaterials are known for being flexible building units that can…

In this paper, we consider near cloaking for the full Maxwell equations. We extend the recent results, where the quasi-static limit case and the Helmholtz equation are considered, to electromagnetic scattering problems. We construct very…

Analysis of PDEs · Mathematics 2012-12-27 Habib Ammari , Hyeonbae Kang , Hyundae Lee , Mikyoung Lim , Sanghyeon Yu

Space folding techniques based on non-monotonic transforms lead to a new class of cylindrical isotropic acoustic cloaks with a constant negative density and a spatially varying negative bulk modulus. We consider an external cloak consisting…

Computational Physics · Physics 2021-01-01 Sebastien Guenneau , Bruno Lombard , Cedric Bellis

We are concerned with the acoustic scattering problem by many small rigid obstacles of arbitrary shapes. We give a sufficient condition on the number $M$ and the diameter $a$ of the obstacles as well as the minimum distance $d$ between them…

Analysis of PDEs · Mathematics 2016-10-20 Durga Prasad Challa , Mourad Sini

We consider approximate cloaking from a regularization viewpoint introduced in [13] for EIT and further investigated in [12] [17] for the Helmholtz equation. The cloaking schemes in [12] and [17] are shown to be (optimally) within…

Analysis of PDEs · Mathematics 2015-05-30 Jingzhi Li , Hongyu Liu , Hongpeng Sun