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1. Thermophone or the future of ultrasound transducers: Modelling of thermoacoustics generation in porous materials

Author

Pierre Guiraud, Stefano Giordano, Olivier Bou Matar, Philippe PERNOD, Raphael Lardat, Zhi Lin Ngoh, Dunlin Tan, Edwin Hang Tong Teo, Philippe Coquet, Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Acoustique Impulsionnelle & Magnéto-Acoustique Non linéaire - Fluides, Interfaces Liquides & Micro-Systèmes - IEMN (AIMAN-FILMS-IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Acoustique Impulsionnelle & Magnéto-Acoustique Non linéaire - Fluides, Interfaces Liquides & Micro-Systèmes - IEMN (AIMAN-FILMS - IEMN), Institut d’Électronique, de Microélectronique et de Nanotechnologie - Département Opto-Acousto-Électronique - UMR 8520 (IEMN-DOAE), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-INSA Institut National des Sciences Appliquées Hauts-de-France (INSA Hauts-De-France)-Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-INSA Institut National des Sciences Appliquées Hauts-de-France (INSA Hauts-De-France)

Subjects
[PHYS]Physics [physics], [SPI]Engineering Sciences [physics]
Abstract

International audience; Electroacoustic transducers along with piezoelectric devices are the most widely used methods for acoustic sound generation in gas and liquids. A mechanical movement of a membrane induces fluid vibration thus creating an acoustic wave. The thermoacoustic process on the other hand uses fast paces temperature variations in a sample to excite the fluid (generally air). The rapidly changing temperature generate a compression expansion of the air and thus creates an acoustical wave. Such materials are called thermophones. They were discovered in the same time period as traditional electroacoustic transducers but their limited efficiency coupled with the technological limits of fabrication prevented scientific craze at the time. In 1999 a new thermophone was presented with a significant improvement compared to the samples used a century prior. This article coupled with the newly found ease of access to complex fabrication process of nanomaterials rekindle the interest in thermoacoustic for audio purposes. In this work a thorough literature review is presented and a novel multilayer model for thermoacoustic sound generation is derived. This model was solved for plane wave, cylindrical wave and spherical wave generation. Another model based on a two temperatures hypothesis for plane wave generation is also solved to represent more accurately the generation of thick porous thermophones. An extensive analysis of those models allowed for a detailed understanding of the thermoacoustic sound generation: its strengths, weaknesses and differences with traditional speakers. Lastly, experimental investigations of porous carbon foams in partnership with CINTRA Singapore are presented. Validation of the models and insights about the handling of such flexible and lightweighted but fragile samples are presented as well at their potential applications for scientific or commercial purposes as broad band sensors.

Published
2020

2. Scattering from a finite ribbed plate with attached oscillators

Author

Charles Croënne, Anne-Christine Hladky, Fernand Léon, Farid Chati, Mai Pham Thi, Dominique Décultot, Raphael Lardat, Michel Tran-Van-Nhieu, Laurent Divay, Gérard Maze, Bertrand Dubus, Thales Research and Technology [Palaiseau], THALES, Laboratoire Ondes et Milieux Complexes (LOMC), Centre National de la Recherche Scientifique (CNRS)-Université Le Havre Normandie (ULH), Normandie Université (NU)-Normandie Université (NU), Thales Underwater Systems, Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Acoustique - IEMN, Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), THALES [France], Université Le Havre Normandie (ULH), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS), and Acoustique - IEMN (ACOUSTIQUE - IEMN)

Subjects
Materials science, Acoustics and Ultrasonics, Polymers, Optical interference, Acoustics, Phonon scattering, Gaussian processes, Near and far field, 01 natural sciences, Resonance (particle physics), Rod, 03 medical and health sciences, 0302 clinical medicine, Arts and Humanities (miscellaneous), 0103 physical sciences, Structural acoustics, Finite-element analysis, Oscilloscopes, 030223 otorhinolaryngology, 010301 acoustics, Naval research, [PHYS]Physics [physics], Scattering, Plane (geometry), Crystal optics, Finite element method, Flexural waves, Elastic modulus
Abstract

Double layer structures consisting of stainless steel and polymer rods are designed to blur and attenuate Bragg and Bloch-Floquet scattering from a periodically ribbed plate in a given frequency bandwidth. These structures can be considered as ribbed plate-spring-mass systems, the resonance frequencies of which are obtained from random and circular permutations of five basic oscillators. Analytical and finite element methods are used to find their parameters and tank tests have been carried out to ensure the accuracy of the numerical results and validate the relevance of such a model. It has been found that the typical features associated with the periodicity of the ribs are replaced by a “Christmas tree” appearance when the far field pressure backscattered from the model is displayed in the (frequency, aspect angle) plane. An analysis of backscattering patterns is presented and comparisons with Naval Research Laboratory results are made.Double layer structures consisting of stainless steel and polymer rods are designed to blur and attenuate Bragg and Bloch-Floquet scattering from a periodically ribbed plate in a given frequency bandwidth. These structures can be considered as ribbed plate-spring-mass systems, the resonance frequencies of which are obtained from random and circular permutations of five basic oscillators. Analytical and finite element methods are used to find their parameters and tank tests have been carried out to ensure the accuracy of the numerical results and validate the relevance of such a model. It has been found that the typical features associated with the periodicity of the ribs are replaced by a “Christmas tree” appearance when the far field pressure backscattered from the model is displayed in the (frequency, aspect angle) plane. An analysis of backscattering patterns is presented and comparisons with Naval Research Laboratory results are made.

Published
2018
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3. Thermoacoustic sound generation model in porous nanomaterials

Author

Pierre Guiraud, Stefano Giordano, Olivier Bou Matar, Raphael Lardat, Philippe PERNOD, Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Acoustique Impulsionnelle & Magnéto-Acoustique Non linéaire - Fluides, Interfaces Liquides & Micro-Systèmes - IEMN (AIMAN-FILMS-IEMN), Institut d’Électronique, de Microélectronique et de Nanotechnologie - Département Opto-Acousto-Électronique - UMR 8520 (IEMN-DOAE), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-INSA Institut National des Sciences Appliquées Hauts-de-France (INSA Hauts-De-France)-Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-INSA Institut National des Sciences Appliquées Hauts-de-France (INSA Hauts-De-France), Acoustique Impulsionnelle & Magnéto-Acoustique Non linéaire - Fluides, Interfaces Liquides & Micro-Systèmes - IEMN (AIMAN-FILMS - IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)

Subjects
[PHYS]Physics [physics], Thermoacoustic, Two Temperature Model, [PHYS.MECA]Physics [physics]/Mechanics [physics], Thermophone, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Porous Material, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph]
Abstract

International audience; Traditional sound generation transducers are using a magnet/coil/membrane system to induce a particle velocity boundary condition to move the air in order to produce sound. Piezoelectric devices are also electromechanical transducer that are also used for sound generation in cases where common loudspeakers fail to perform (underwater sound generation, high frequency sound generation...) However, both devices share the same limits being having a non-flexible design and no broad band sound generation (resonant behavior). The thermoacoustic principle is a novel way of generating sound. When an alternative current is applied to a nanomaterials having a high thermal conductivity and low thermal capacity, the heat profile of the material will follow accurately the electrical one. The air in the vicinity of the sample will compress and dilate due to the rapid heating and cooling, thus creating a pressure boundary condition, as opposed to a velocity one, generating a sound wave. Theoretically this principal is independent of the geometry of the sample and is broadband, ranging from a few Hertz to several Mega Hertz. This principle was known for more than a hundred years [1] but has recently gained interest due to new technologies improving the ease of fabrication and access of certain nanomaterials. In the last two decades many nanomaterials have been tested as potential thermophone sources [2] like suspended metal wires (carbon, gold, aluminum…) or carbon based material in different shapes (laser scribed, paper, sponge, nanotube forest, foam…). Nevertheless, due to the only recently gained momentum of the field and of the complex geometry of most thermophones, there is no current global theory about thermoacoustic generation. Models are approximated on a case by case basis and focus mostly on the acoustical hearing range in air. This paper will propose a novel broadband model that takes into account the complex geometry of 3D thermophones, and most specifically, foam like material. The thermal equilibrium is assumed to not be achieved inside the sample and a two temperature method will be used to analyse the 1D response of a thermophone in free field. The model's equations are based on the conservation of mass, momentum, energy in the fluid and the conservation of energy in the solid. This model will then be compared to the solution provided by one of the most recent approach for thermoacoustic generation [3] (based on a one temperature model), assuming a continuous thermophone but considering the sound propagation in the solid.

Published
2019

4. Two-temperature model for the thermoacoustic sound generation in porous materials

Author

Pierre Guiraud, Stefano Giordano, Olivier Bou Matar, Philippe PERNOD, Raphael Lardat, Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Acoustique Impulsionnelle & Magnéto-Acoustique Non linéaire - Fluides, Interfaces Liquides & Micro-Systèmes - IEMN (AIMAN-FILMS-IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Institut d’Électronique, de Microélectronique et de Nanotechnologie - Département Opto-Acousto-Électronique - UMR 8520 (IEMN-DOAE), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-INSA Institut National des Sciences Appliquées Hauts-de-France (INSA Hauts-De-France)-Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-INSA Institut National des Sciences Appliquées Hauts-de-France (INSA Hauts-De-France), and Acoustique Impulsionnelle & Magnéto-Acoustique Non linéaire - Fluides, Interfaces Liquides & Micro-Systèmes - IEMN (AIMAN-FILMS - IEMN)

Subjects
[PHYS]Physics [physics], [PHYS.MECA]Physics [physics]/Mechanics [physics], ComputingMilieux_MISCELLANEOUS, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph]
Abstract

International audience

Published
2019

5. Acoustic antenna based on fiber laser hydrophones

Author

R. Bouffaron, C. Bergogne, Martine Doisy, Gérard Roux, F.-X. Launay, and Raphael Lardat

Subjects
Nonlinear system, Signal-to-noise ratio, Materials science, Optics, Hydrophone, Fiber optic sensor, business.industry, Acoustics, Fiber laser, Antenna (radio), business, Pulse (physics), Power (physics)
Abstract

A technique to enhance the response of Brillouin distributed sensors is proposed and experimentally validated. The method consists in creating a multi-frequency pump pulse interacting with a multi-frequency continuous-wave probe. The power of each pulse at a distinct frequency is lower than the threshold for nonlinear effects, while the sensor response remains given by the total power of all pulses. Distinct frequency pulses are delayed to avoid temporal overlapping and cross-interaction; this requires to smartly reconstruct the traces before photo-detection. The method is validated in a 50 km-long sensor using 3 frequencies, demonstrating a signal-to-noise ratio enhancement of 4.8 dB.

Published
2014
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6. Interaction between a Pulsating Flow and a Perforated Membrane

Author

Bruno Koobus, Eric Schall, Jean-Fran~ois Guery, Alain Dervieux, Raphael Lardat, Charbel Farhat, Romuald Carpentier, Patrick Della Pieta, Département de Mathématiques [Montpellier], Université Montpellier 2 - Sciences et Techniques (UM2), Numerical Simulation for the Engineering Sciences (SINUS), Inria Sophia Antipolis - Méditerranée (CRISAM), Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Temex, LABORATOIRE DE THERMIQUE ENERGETIQUE ET PROCEDES (EA1932) (LATEP), Université de Pau et des Pays de l'Adour (UPPA), Simulation, modeling and analysis of heterogeneous systems (SMASH), Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Université de Provence - Aix-Marseille 1, Center for Aerospace Structures (CAS), University of Colorado [Boulder], Department of Aerospace Engineering Sciences, and Laboratoire de Génie Thermique Énergétique et Procédés (EA1932) (LATEP)

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Mathematics::Analysis of PDEs, Computational Mechanics, Shell (structure), Diaphragm (mechanical device), 01 natural sciences, 010305 fluids & plasmas, Physics::Fluid Dynamics, symbols.namesake, Inviscid flow, 0103 physical sciences, Fluid–structure interaction, Astrophysics::Solar and Stellar Astrophysics, Tube (fluid conveyance), 0101 mathematics, ComputingMilieux_MISCELLANEOUS, Mathematics, Mechanical Engineering, Mechanics, Solver, Euler equations, 010101 applied mathematics, Computational Mathematics, Amplitude, Classical mechanics, Mechanics of Materials, Modeling and Simulation, symbols, [MATH.MATH-NA]Mathematics [math]/Numerical Analysis [math.NA]
Abstract

A fully ALE 3D approach involving a Navier-Stokes solver is applied to the study of the interaction of a pulsating flow in a tube with a perforated diaphragm. We concentrate on an inviscid flow and the structure is modelled through shell elements. The effect on the first mode of the structure is examined with the study of the influence of the pulsation amplitude and of the pulsation frequency.

Published
2000
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7. Static pressure and temperature compensated wideband fiber laser hydrophone

Author

Martine Doisy, C. Bergogne, R. Bouffaron, F.-X. Launay, Raphael Lardat, and Gérard Roux

Subjects
Reduced properties, Materials science, Hydrophone, Acoustics, Fiber laser, Hydrostatic pressure, Static pressure, Wideband, Sensitivity (electronics), Low noise
Abstract

Sensitive optical hydrophone is a key component for the design of compact fully optical acoustic arrays and one major issue about this kind of sensors is their sensitivity to hydrostatic pressure and temperature. We present in this paper a compact hydrophone which is optimized for reduced temperature sensitivity and high static pressure capability. High acoustic sensitivity is obtained through wideband mechanical amplification design. Two mock-ups have been realized and the measurements show good agreements with finite-element model. We present acoustic measurements as well as measurements in environmental conditions (temperature and pressure) obtained with a low noise opto-electronic interrogation system.

Published
2013
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8. All-optical acoustic array for underwater surveillance

Author

P. Brechat, Martine Doisy, Raphael Lardat, R. Bouffaron, C. Bergogne, F.-X. Launay, Alain Mugnier, David Pureur, D. Billet, Yohann Léguillon, Gérard Roux, Stephanie Molin, and Pascal Besnard

Subjects
Optical fiber cable, Multi-mode optical fiber, Materials science, Hydrophone, business.industry, Physics::Optics, Distributed acoustic sensing, Fiber-optic communication, law.invention, Optics, law, Fiber optic sensor, Fiber optic splitter, Underwater, business
Abstract

For underwater surveillance applications, an all-optical acoustic array technology allows enhanced capabilities compared to conventional piezoelectric antenna in terms of compactness, robustness and large distance remote interrogation through small diameter optical cable. This paper presents the results obtained on a first full optical antenna panel based on an innovative wideband pressure and temperature compensated fiber laser hydrophone. The presented mock-up includes 12 fiber-laser optical hydrophones interrogated through a 4 km lead optical cable.

Published
2013
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9. FEM/BEM Analysis for SAW devices

Author

Marc Solal, Toufic Abboud, Sylvain Ballandras, Stéphane Chamaly, Vincent Laude, Raphael Lardat, Thomas Pastureaud, Jonas Ribbe, William Steichen, Pascal Ventura, Temex, Centre de Mathématiques Appliquées (CMAP), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174) (FEMTO-ST), Université de Technologie de Belfort-Montbeliard (UTBM)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS), and Ken-Ya Hashimoto

Subjects
[SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph]
Abstract

paper 3a2 (18 pages) on proceedings CD-ROM; International audience

Published
2004

10. Application of Unsteady Fluid-Structure Methods to Problems in Aeronautics and Space

Author

Eric Schall, Raphael Lardat, Alain Dervieux, Charbel Farhat, and Bruno Koobus

Subjects
Physics::Fluid Dynamics, Finite volume method, Aeronautics, business.industry, Computer science, Aerospace engineering, Computational fluid dynamics, business, Arbitrary lagrangian eulerian, Aerospace, Compressible flow, Vertex (geometry)
Abstract

We are interested by the unsteady fluid-structure coupling with a compressible fluid model performed in a cooperation between an INRIA group in CFD and the Center for Aerospace structure of University of Boulder. A particular focus is put on the fluid part, which involves the MUSCL-FEM technology relying on a vertex centered upwind finite volume formulation for unstructured tetrahedrizations, and a mesh deformation technique combined with an Arbitrary Lagrange-Euler formulation. Three typical applications will then be presented.

Published
2003
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11. Analysis of a possible coupling in a thrust inverter

Author

Raphael Lardat, Eric Schall, Bruno Koobus, Alain Dervieux, Charbel Farhat, Département de Mathématiques [Montpellier], Université Montpellier 2 - Sciences et Techniques (UM2), Numerical Simulation for the Engineering Sciences (SINUS), Inria Sophia Antipolis - Méditerranée (CRISAM), Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Temex, Laboratoire de Génie Thermique Énergétique et Procédés (EA1932) (LATEP), Université de Pau et des Pays de l'Adour (UPPA), Simulation, modeling and analysis of heterogeneous systems (SMASH), Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Université de Provence - Aix-Marseille 1, Center for Aerospace Structures (CAS), University of Colorado [Boulder], Department of Aerospace Engineering Sciences, and LABORATOIRE DE THERMIQUE ENERGETIQUE ET PROCEDES (EA1932) (LATEP)

Subjects
Computational Mechanics, Thrust, Geometry, 01 natural sciences, Compressible flow, 010305 fluids & plasmas, Physics::Fluid Dynamics, symbols.namesake, 0103 physical sciences, Fluid–structure interaction, 0101 mathematics, ComputingMilieux_MISCELLANEOUS, Mathematics, Mechanical Engineering, Mechanics, Solver, Finite element method, Euler equations, 010101 applied mathematics, Computational Mathematics, Flow (mathematics), Mechanics of Materials, Modeling and Simulation, symbols, Inverter, [MATH.MATH-NA]Mathematics [math]/Numerical Analysis [math.NA]
Abstract

We present the study of the interaction between the flow in a thrust inverter and a flap playing a central role in the flow deviation. The flow is limited by a rather closed vessel and presents acoustic modes which can be amplified by recirculations. Such modes may interfere with structural modes. The analysis is conducted with a fully ALE 3D approach involving a nonlinear compressible flow solver, coupled with a shell finite element model.

Published
2000

12. Aeroelastic coupling between a thin divergent and high pressure jets

Author

Alain Dervieux, Charbel Farhat, Eric Schall, Bruno Koobus, Raphael Lardat, Département de Mathématiques [Montpellier], Université Montpellier 2 - Sciences et Techniques (UM2), LABORATOIRE DE THERMIQUE ENERGETIQUE ET PROCEDES (EA1932) (LATEP), Université de Pau et des Pays de l'Adour (UPPA), Numerical Simulation for the Engineering Sciences (SINUS), Inria Sophia Antipolis - Méditerranée (CRISAM), Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Temex, Simulation, modeling and analysis of heterogeneous systems (SMASH), Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Université de Provence - Aix-Marseille 1, Center for Aerospace Structures (CAS), University of Colorado [Boulder], Department of Aerospace Engineering Sciences, and Laboratoire de Génie Thermique Énergétique et Procédés (EA1932) (LATEP)

Subjects
business.product_category, Computational Mechanics, Geometry, Thrust, 01 natural sciences, 010305 fluids & plasmas, symbols.namesake, 0103 physical sciences, Fluid–structure interaction, 0101 mathematics, ComputingMilieux_MISCELLANEOUS, Physics, Jet (fluid), Mechanical Engineering, Aeroelasticity, Euler equations, 010101 applied mathematics, Computational Mathematics, Coupling (physics), Rocket, Mechanics of Materials, Modeling and Simulation, High pressure, Physics::Space Physics, symbols, High Energy Physics::Experiment, business, [MATH.MATH-NA]Mathematics [math]/Numerical Analysis [math.NA]
Abstract

Rocket divergents concentrate the engine thrust on a light structure. This thrust may provoke deformations, and these deformations may influence the jet. For analysis, we formulate a coupled fluid/...

Published
2000

13. 3D Simulation of periodic surface wave inter‐digital transducer using finite element/boundary element analysis

Author

W. Steichen, Sylvain Ballandras, M. Wilm, William Daniau, Alexandre Reinhardt, and Raphael Lardat

Subjects
Physics, Surface (mathematics), Acoustics and Ultrasonics, business.industry, Acoustics, Surface acoustic wave, Boundary (topology), Finite element method, Optics, Transducer, Arts and Humanities (miscellaneous), Surface wave, Surface acoustic wave sensor, Development (differential geometry), business
Abstract

Spectacular advances have been made during the past years in the development of surface acoustic wave thanks to technology improvements but also to a strong effort in the modelling and design of such devices, taking into account their actual structure to benefit from second order effects (for instance the influence of the metal strip shape used in inter‐digital transducers on the wave propagating under periodic gratings). In this paper, we present a 2D‐periodic 3D‐simulation approach to compute the spectral response of one period of a surface wave transducer, accounting for the actual shape of the electrodes as well as realistic guiding conditions and acoustic properties of the propagation surface. The idea consists in meshing the inhomogeneous part of the transducer, i.e. the electrodes and the bus bar, as well as a thin layer of the substrate to match the finite element section with surface boundary elements simulating the acoustic contribution of the substrate (propagation and radiation). Periodic boun...

Published
2008
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14. An analytical model for piezoelectric/elastic axisymmetric bender disks radiating in water

Author

Raphael Lardat

Subjects
Physics, Coupling, Radiation impedance, Admittance, Classical mechanics, Acoustics and Ultrasonics, Arts and Humanities (miscellaneous), Differential equation, Harmonic, Mechanics, Radius, Piezoelectricity, Coupling coefficient of resonators
Abstract

Flextensional transducers have been widely studied for low frequency SONAR application due to the low celerity of the flexion wave. In this work, we will describe in detail a complete analytical model for an axisymmetric disk made of one elastic plate on which two piezoelectric disks of smaller radius have been reported on each side. The model, starting from flexural axisymmetric theory and from the piezoelectric equations, finally comprises local radiation impedance and mutual coupling with neighboring disks. In particular, we will explain the continuity conditions that are to be imposed at the external radius of the piezoelectric disk. We also show how to include a radiation force opposed and proportional to the normal velocity inside the analytical solution given by a fourth order differential equation. The described model is then able to compute a large number of parameters such as Eigen modes, harmonic admittance, radiated pressure, coupling coefficient and static and dynamic stresses. The validity o...

Published
2008
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15. Theoretical analysis of damping effects of SAW at solid/fluid interfaces

Author

Sylvain Ballandras, Thomas Pastureaud, Raphael Lardat, Alexandre Reinhardt, William Daniau, Vincent Laude, Mikael Wilm, Jean-Bernard Briot, Virginie BLONDEAU-PATISSIER, Wilfrid Boireau, Abdelkrim Khelif, Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174) (FEMTO-ST), Université de Technologie de Belfort-Montbeliard (UTBM)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS), and Temex

Subjects
[SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], ComputingMilieux_MISCELLANEOUS, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph]
Abstract

International audience

16. Theorical analysis of damping effects of SAW at solid/fluid interfaces

Author

Sylvain Ballandras, Thomas Pastureaud, Raphael Lardat, Alexandre Reinhardt, William Daniau, Vincent Laude, Mikaël Wilm, Briot, J. B., Virginie Blondeau-Patissier, Wilfrid Boireau, Abdelkrim Khelif, Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174) (FEMTO-ST), Université de Technologie de Belfort-Montbeliard (UTBM)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Université de Franche-Comté (UFC), and Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], ComputingMilieux_MISCELLANEOUS, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph]
Abstract

International audience

17. Analyse théorique et expérimentale de l'efficacité de mousse de carbone pour génération acoustique dans des milieux visqueux

Author

GUIRAUD, Pierre, Henri, Olivier Bou Matar-Lacaze, Stefano Giordano, Franck Levassort [Président], Diana-Georgiana Baltean [Rapporteur], Pierrick Lotton [Rapporteur], Juliette Pierre, Philippe Pernod, Raphael Lardat, Philippe Coquet, and Philippe Pouliguen

Subjects
Carbone, Modèle théorique, Nanomatériaux, Thermoacoustique, Génération sonore, Thermophone, Matériaux poreux

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