Aqui você encontrará apresentações realizadas nas Conferências de Usuários COMSOL de todo o mundo. As apresentações englobam pesquisas e produtos inovadores feitas por engenheiros e cientistas usando o COMSOL Multiphysics. Os tópicos abramgem uma grande gama de indústrias e aplicações, como elétrica, mecânica, escoamento e química. Use a função de busca "Quick Search" para encontrar apresentações na sua área de interesse.

Characterization of a Tonpilz Transducer and Performance Analysis for a MEMS-Transducer Array

V. Vadde, and B. Lakshmi G

In this paper, we develop and analyze a standard piezoacoustic Tonpilz-transducer model for underwater acoustics in Comsol by addressing the attendant piezoelectric and pressure acoustic multiphysics phenomena. Transducer properties that are studied and characterized are the center frequency, bandwidth, linearity, sensitivity, and noise figure. In an effort to miniaturize the transducer, a ...

A Finite Element Model of Shear Wave Propagation Induced by an Acoustic Radiation Force Impulse

R. De Luca[1,2], J. Fromageau[1], H.W. Chan[1], F. Marinozzi[2], J. Bamber[1]
[1]Institute of Cancer Research and Royal Marsden Hospital, Sutton, England, United Kingdom
[2]Sapienza University of Rome, Dept. of Mechanical and Aerospace Engineering, Rome, Italy

Shear wave elastography is an innovative technique used in combination with the traditional ultrasound imaging to improve the specificity of cancer imaging. A two-dimensional finite element model (FEM), composed of realistic boundary conditions, was developed in COMSOL Multiphysics® to simulate the propagation of shear waves induced by an acoustic radiation force impulse (ARFI) in isotropic, ...

Study & Modeling of 'Acoustic Matching Layers' for Ultrasound Imaging Probes Through Pulse-Echo FEM Simulation - new

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

Ultrasound Imaging probes are specific devices that require a very detailed design of acoustic impedance match for the stack of layers that form the probe head (1,3). These are typically made of silicone rubber, special epoxy resins, polyurethanes and, of course, piezoelectric materials. The acoustic impedance, measured in Rayls, have to be matched similarly to an electric circuit (2), from a ...

Optimal Design of Slit Resonators for Acoustic Normal Mode Control in Rectangular Rooms

S. Floody[1], R. Venegas[2], and F. Leighton[3]
[1]Universidad de Chile, Facultad de Artes, Departamento de Música y Sonología, Licenciatura en Sonido, Santiago, Chile
[2]University of Salford, Acoustics Research Centre, Salford, UK
[3]Universidad Tecnológica de Chile Inacap, Sede Pérez Rosales, Santiago, Chile

The present article presents a method to redistribute the acoustic modes of a rectangular enclosure in the low frequency range using slit resonators. The objective of the present work is to compare different strategies of optimal design in order to determine the dimensions of the resonators. The method of the finite elements will be used to model the acoustic physical behavior of the room. In ...

Thermal Analysis of a Piezo-Disk Ultrasound Probe

L. Spicci[1], M. Cati[1]
[1]Esaote, Firenze, Italy

Ultrasound imaging probes are widely used for several types of diagnosis applications. In the present work we focus our attention on a disk-type probe, which is widely used in CW and PW operating conditions. In particular we present a 2D-axial symmetry FEM for the probe, capable to predict both the operative temperature values at different driving signal frequencies, both the heating dynamics. ...

Acoustical Design of Stethoscope for Improved Performance

C. Thiagarajan[1], Gururajan R.[2], A. H. Baig[2], Prema S.[3]
[1]ATOA Scientific Technologies Pvt Ltd, Whitefield, Bangalore, Karnataka India
[2]University of Southern Queensland, Toowoomba Qld 4350, Australia.
[3]RMK Engineering College, Chennai, Tamil Nadu, India

Stethoscope is in use for more than 200 years for medical diagnostics, especially for auscultation. Recently, the unprecedented growth in mobile technology revived the use of stethoscope for Telehealthcare. Digital or electronic stethoscopes are increasingly researched for use in Telehealthcare. This paper mainly focuses on the acoustical and multiphysics design aspects of the stethoscope for ...

Feed-forward/Feed-backward Mechanical Amplification in the Mouse Cochlea

J. Soons[1,2], C. Steele[2], S. Puria[2]
[1]Lab of Biomedical physics, University of Antwerp, Antwerp, Belgium
[2]Department of Mechanical Engineering, Stanford University, Stanford, USA

Sound vibrations are collected from the external environment by the eardrum and are guided to the basilar membrane in the cochlea. Pressure differences in the two scalae of the cochlea result in a traveling wave on the basilar membrane. The tiny displacements are detected by the deflection of thousands of hair cells, situated along this membrane. It is hypothesized that some 3/4 of these hair ...

Numerical Simulation of Acoustic Properties of Porous Metals under High Sound Pressure Level Conditions

B. Zhang [1], X. Wang [1], L. Ni [1]
[1] School of Mechanical Engineering, Ningxia University, China

The sound propagation and absorption properties in porous media under high sound pressure level conditions have been reported elsewhere. Also several analytical and semi-analytical solutions have been developed; however, these solutions are relatively complicated and the provided results are not accurate enough yet. In this work, the simulated results for the study of the sound absorption ...

Analysis of Sound Propagation in Lined Ducts by Means of a Finite Element Model

D. Borelli[1] and C. Schenone[1]
[1]DIPTEM, University of Genova, Genova, Italy

The present paper describes the results of a Finite Element Model used to analyze sound propagation in lined ducts. By means of a numerical model it was possible to predict the insertion loss inside rectangular lined ducts in a frequency range from 250 Hz to 4000 Hz. The model was validated by a comparison with experimental data obtained in accordance to ISO 11691 and ISO 7235 standards. The ...

Optimization of an Acoustic Waveguide for Professional Audio Applications

M. Cobianchi[1] and R. Magalotti[1]
[1] B&C Speakers S.p.a., Bagno a Ripoli, FI, Italia

In modern live sound reinforcement there is a growing use of line sources, obtained through the stacking of many loudspeakers with properly controlled wavefront shape. Thus the use of waveguides is mandatory in order to modify the shape and size of the wavefront exiting from professional compression drivers. With the help of COMSOL Multiphysics®, we have designed a waveguide featuring an ...