Analogy electromagnetism-acoustics: Validation and application to local impedance active control for sound absorption

Nicolas, Laurent; Furstoss, Marc; Galland, Marie‐Annick

doi:10.1051/epjap:1998247

Cited by 8 publications

(5 citation statements)

References 8 publications

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“…In this work, we show that by choosing different Lagrangians and different representations of the acoustic fields by scalar and vector potentials (keeping the equations of motion invariant) one can derive different canonical momentum and angular-momentum densities, containing both scalar and vector degrees of freedom including non-zero spin (2). Throughout the paper, we highlight the mathematical analogy between electromagnetism and acoustics [33,7,8,4,9]. In electromagnetism, choosing representations and Lagrangians based on electric or magnetic potentials result in the canonical quantities involving only electric or magnetic fields, respectively; Eqs.…”

Section: Introductionmentioning

confidence: 99%

Acoustic versus electromagnetic field theory: scalar, vector, spinor representations and the emergence of acoustic spin

et al. 2020

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We construct a novel Lagrangian representation of acoustic field theory that accounts for the local vector properties of longitudinal (curl-free) acoustic fields. In particular, this approach describes the recently-discovered nonzero spin angular momentum density in inhomogeneous sound fields in fluids or gases. The traditional acoustic Lagrangian representation with a scalar potential is unable to describe such vector properties of acoustic fields adequately, which are however observable via local radiation forces and torques on small probe particles. By introducing a displacement vector potential analogous to the electromagnetic vector potential, we derive the appropriate canonical momentum and spin densities as conserved Noether currents. The results are consistent with recent theoretical analyses and experiments. Furthermore, by an analogy with dual-symmetric electromagnetic field theory that combines electric-and magnetic-potential representations, we put forward an acoustic spinor representation combining the scalar and vector representations. This approach also includes naturally coupling to sources. The strong analogies between electromagnetism and acoustics suggest further productive inquiry, particularly regarding the nature of the apparent spacetime symmetries inherent to acoustic fields.

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Section: Introductionmentioning

confidence: 99%

Acoustic versus electromagnetic field theory: scalar, vector, spinor representations and the emergence of acoustic spin

et al. 2020

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“…Some works thus addressed this aspect, considering the influence of incidence angles or the behavior of 3D volumes. For example, a speaker array was used to control an oblique incident plane wave [22], dipolar sources were used to damp the first modes of a small room [23], an array of hybrid cells was studied under various incidences [24], or an hybrid cell has been used to dampen a structural-acoustic coupled system [25].…”

Section: Introductionmentioning

confidence: 99%

Active Control in an Anechoic Room: Theory and First Simulations

Habault¹,

Friot²,

Herzog³

et al. 2017

Acta Acustica united with Acustica

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International audienceNoise control and source design require the measurement of sound radiation at lowfrequencies. Anechoic rooms, which are designed for this purpose, allowe cho-free measurements at medium or high frequencyb ut passive wall treatment is less effective at lowf requencya nd in practice no facility provides anechoicity below5 0Hz. This paper discusses the applicability of an active control algorithm which has been previously introduced to minimize the echoes from ascattering object to the cancellation of the lowfrequencywall echoes in an anechoic room including wall-embedded secondary sources. At first the paper discusses, in the general case then for afree half-space as amodel case, the algorithm keywhich consists in estimating the scattered acoustic pressure from total pressure measurements. Boundary Element Method computations are secondly used to simulate estimation and active control of error signals accounting for the low-frequencyscattered pressure in an anechoic room. The simulations showt hat control with af ew dozen microphones and noise sources allows al arge reduction of the noise scattered from the walls at low-frequency

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“…Acoustic pressure and particle velocity corresponded to the electric-field and the magnetic-field, respectively, and acoustic intensity corresponded to the Poynting vector ( Williams and Valdivia, 2010 ). There is also an important analogy between the acoustic properties of the acoustic medium, and the complex conductivity, permeability and permittivity of the neural tissue ( Nicolas et al, 1998 ). We obtained the relevant conductivity values from direct measurements in rodent neocortex given in the literature by layer, and across and along layers.…”

Section: Methodsmentioning

confidence: 99%

Near-field electromagnetic holography for high-resolution analysis of network interactions in neuronal tissue

Kjeldsen

Kaiser

Whittington

2015

Journal of Neuroscience Methods

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Analogy electromagnetism-acoustics: Validation and application to local impedance active control for sound absorption

Cited by 8 publications

References 8 publications

Acoustic versus electromagnetic field theory: scalar, vector, spinor representations and the emergence of acoustic spin

Acoustic versus electromagnetic field theory: scalar, vector, spinor representations and the emergence of acoustic spin

Active Control in an Anechoic Room: Theory and First Simulations

Near-field electromagnetic holography for high-resolution analysis of network interactions in neuronal tissue

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