0000000000540159

AUTHOR

Emmanuel Gourdon

showing 2 related works from this author

Sound absorption prediction of linear damped acoustic resonators using a lightweight hybrid model

2019

International audience; A lightweight numerical method is developed to predict the sound absorption coefficient of resonators whose cross-section dimensions are significantly larger compared to the viscous and thermal boundary layer’s thicknesses. This method is based on the boundary layer theory and on the perturbations theory. According to the perturbations theory, in acoustical domains with large dimensions, the fluid viscosity and thermal conductivity only affect the boundary layers. The model proposed in this article combines the lossless Helmholtz wave equation derived from a perfect fluid hypothesis, with viscosity and thermal conductivity values of a real fluid to compute the sound …

PhysicsAcoustics and UltrasonicsComputation efficiencyNumerical analysisAcousticsResonance absorbersDissipationWave equation01 natural sciences7. Clean energy[PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph]010305 fluids & plasmasBoundary layer theoryViscothermal lossesBoundary layersymbols.namesakeViscosityNoise reduction coefficientResonatorHelmholtz free energy0103 physical sciencessymbolsSound absorptionAcoustic modeling010301 acousticsApplied Acoustics
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Experimental analysis of acoustical properties of irregular cavities using laser refracto-vibrometry

2018

International audience; In this paper, the Scanning Laser Doppler Vibrometer (SLDV) is used to measure acoustic pressure in small regions of cavities for the study of acoustical localization. It is shown that this optical method leads to interesting information on localized acoustical modes inside irregular cavities, which are very difficult to observe using conventional microphone measurements. Indeed, localization regions are often of comparable size or even smaller than a typical microphone which can make this type of sensor intrusive. The SLDV is used to measure sound pressure after deriving the refracto-vibrometry method from its standard use. Data are obtained in a large area with a h…

Materials scienceAcoustics and UltrasonicsMicrophonebusiness.industryAcousticsAcoustic localizationIrregular cavitiesLaser01 natural scienceslaw.invention[PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph]010309 opticsResonatorNoise reduction coefficientOpticsQuality (physics)law0103 physical sciencesAcoustic dampingRefracto-vibrometrySound pressurebusiness010301 acousticsImage resolutionEnergy (signal processing)
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