Ici vous trouverez les présentations issues des Conférences COMSOL à travers le monde. Réalisées par des utilisateurs de COMSOL Multiphysics, ces présentations explorent tous les domaines actuels d'innovation. Les applications couvrent pratiquement tous les secteurs industriels et impliquent des phénomènes électriques, mécaniques, fluidiques et chimiques. Utilisez la recherche rapide pour trouver les présentations les plus intéressantes dans votre domaine d'intérêt.
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COMSOL-News-Magazine-2017-Special-edition-acoustics
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Multiphysics Modeling of Sound Absorbing Fibrous Materials

T. G. Zielinski [1]
[1] Institute of Fundamental Technological Research, Polish Academy of Sciences, Warsaw, Poland

Many of fibrous materials are very good sound absorbers, because the acoustic waves, which propagate in air and penetrate a fibrous layer, interact with the fibers so that the wave energy is dissipated. The dissipation is related to some viscous and thermal effects occurring on the micro-scale level. On the macroscopic level, a fibrous medium can be treated as an effective inviscid fluid, ...

Dynamic Structural Modelling of Wind Turbines Using COMSOL Multiphysics

C. Van der Woude, and S. Narasimhan
University of Waterloo, Waterloo, ON, Canada

This paper presents a study of a wind turbine subjected to wind and seismic loading, carried out using COMSOL Multiphysics. The dynamic properties and response of wind turbine structures are of interest, as recent developments in wind energy have led to the design and construction of increasingly large and flexible turbine structures. A typical turbine structure model was created in COMSOL and ...

FEM Simulation for ‘Pulse-Echo’ Performances of an Ultrasound Imaging Linear Probe

L. Spicci[1]
[1]Esaote SpA, Florence, Italy

Pulse-echo FEM simulation is seldom found in literature for ultrasound imaging array probes, since the complete modeling of such device is extremely complicated. Nevertheless, the 2D FEM described in the present work was successful, thanks to the following design procedure (see figure): Two piezoacoustic models were employed, one for transmission of the pressure wave into the acoustic domain, ...

Simulation of Acoustic Energy Harvesting Using Piezoelectric Plates in a Quarter-Wavelength Straight-Tube Resonator

B. Li[1], J.H. You[1]
[1]Southern Methodist University, Dallas, TX, USA

An acoustic energy harvesting mechanism at low frequency (~200 Hz) using lead zirconate titanate (PZT) piezoelectric cantilever plates placed inside a quarter-wavelength straight-tube resonator has been studied using COMSOL Multiphysics 4.3 and compared with experimental data. When the tube resonator is excited by an incident wave at its acoustic eigenfrequency, an amplified acoustic resonant ...

A Multiphysics Approach to the Design of Loudspeaker Drivers

R. Magalotti [1]
[1] B&C Speakers, Bagno a Ripoli, Italy

Loudspeaker drivers are energy transducers: their main goal is to efficiently convert electrical energy to acoustic energy (sound), through the movement of mechanical parts. As such, they are prime candidates for the application of multiphysics methods and tools. The talk will outline the growing set of tools that COMSOL Multiphysics® software puts in the hands of the loudspeaker designer; ...

CMUT Based Free Membrane Intra-Cardiac Volumetric Blood Flow-Meter

P. Priya [1], B. D. Pant [2],
[1] Birla Institute of Technology and Science Pilani, Pilani, Rajasthan, India
[2] CSIR-Central Electronics Engineering Research Institute, Pilani, Rajasthan, India

In this paper, a free membrane is used as a receiver to increase the capacitance and therefore the resolution of the flow meter. For the current application, from the wavelength of sound wave in soft tissue (c= 1540 m/s) the resolution was calculated to be 0.48 mm. This gives the first Eigen frequency of the capacitive structure according to which the poly silicon membrane was designed. After ...

Prediction of Noise Generated by Electromagnetic Forces in Induction Motors - new

M. K. Nguyen[1], R. Haettel[2], A. Daneryd[2]
[1]KTH, Stockholm, Sweden
[2]ABB Corporate Research,Västerås, Sweden

Induction motors, as any other industrial products, have to comply with various requirements on noise levels. Therefore, it is essential to use an appropriate prediction tool to verify and optimize the design of an induction motor with respect to the acoustic performances. The paper will focus on the prediction of the magnetic noise generated and radiated by a specific motor. The challenge is ...

Modeling Scattering from Rough Poroelastic Surfaces Using COMSOL Multiphysics®

A. Bonomo[1], M. Isakson[1]
[1]Applied Research Laboratories, The University of Texas at Austin, Austin, TX, USA

COMSOL Multiphysics® is used to address the problem of acoustic scattering from one-dimensional rough poroelastic surfaces. The poroelastic sediment is modeled following the Biot-Stoll formulation. The rough surfaces are generated using a modified power law spectrum. Both monostatic and bistatic scattering strengths are calculated. These results are compared with more conventional scattering ...

Solid Rocket Motor Combustion Instability Modeling in COMSOL Multiphysics® Software

S. R. Fischbach [1][2],
[1] Jacobs ESSSA Group, NASA Marshall Space Flight Center, Huntsville, AL, USA
[2] Qualis Corporation, Huntsville, AL, USA

Combustion instability modeling of Solid Rocket Motors (SRM) remains a topic of active research. Many rockets display violent fluctuations in pressure, velocity, and temperature originating from the complex interactions between the combustion process, acoustics, and steady-state gas dynamics. Recent advances in defining the energy transport of disturbances within steady flow-fields have been ...

Acoustic Wave Propagation in Water Filled Buried Polyethylene Pipes - new

T. Graf[1], T. Gisler[1], P. Sollberger[1], O. Schaelli[1]
[1]School of Engineering and Architecture, Lucerne University, Horw, Switzerland

Axisymmetric acoustic waves propagating along buried water pipes have been investigated by FEM and experimentally. Universal dispersion relations of the fundamental mode were obtained as a function of the standard dimension ratio SDR and of the material surrounding the pipe (soil, air). At low frequency there exists little dispersion and the “dc” phase velocity of the leak noise is independent ...