A-S. Moreau, H. Lissek, and R. Boulandet
EPFL-STI-IEL-LEMA, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
In this paper, the underlying concept of electroacoustic absorbers is studied with the help of Comsol Multiphysics® Acoustics Module. Among the different ways to obtain variable acoustic properties on an electroacoustic transducer's voicing face, there is the shunting of the transducer's electrical input. With such shunt devices, the acoustic impedance that the transducer's membrane presents ...
M. Hedges and Y.W. Lam
Acoustics Research Centre, School of Computing, Science & Engineering, University of Salford, Salford, United Kingdom
Monitor Audio Ltd., Rayleigh, Essex, United Kingdom
Loudspeaker simulation is used to inform the designer as to the performance of a design. In recent years the Finite Element Method (FEM) has been used to model the mechanical and acoustical attributes of a loudspeaker with varying success. This paper shows how a model that incorporates the magnetic, electromagnetic, mechanical and acoustical domains performs. These domains will be coupled where ...
Y.L. Rao, and G. Zhang[1-3]
 Micro/Nano Bioengineering Laboratory, Department of Biological and Agricultural Engineering, The University of Georgia
 Nanoscale Science and Engineering Center, The University of Georgia
 Faculty of Engineering, The University of Georgia
Integration of surface acoustic wave (SAW) devices with nanostructures has gained interest in the development of sensors with high sensitivity. To better design nanostructure integrated SAW devices, it is essential to model three dimensional (3-D) SAW devices and analyze the wave propagation characteristics in nanostructure-enhanced SAW devices. In this work, a 3-D finite element model of ...
O. Falou , J.C. Kumaradas, and M.C. Kolios[1,2]
 Dept. of Electrical and Computer Engineering, Ryerson University
 Dept. of Physics, Ryerson University
A finite-element model of wave propagation using COMSOL Multiphysics has been developed to solve the problem of ultrasound scattering from spherical structures. This model will be used to predict ultrasound backscatter from cells for ultrasound tissue characterization, and scattering from microbubble contrast agents. In this paper, we discuss an improvement to our model by using a ...
B. Baumann, M. Wolff[1,2], B. Kost, and H. Groninga
 Hamburg University of Applied Sciences, Faculty of Engineering and Computer Science
 PAS-Tech GmbH
A procedure for the numerical calculation of photoacoustic signals is introduced. It is based on the finite element method and uses an expansion of the signal into acoustical eigenmodes of the measuring cell. The method is verified for cylindrical cells with excellent accordance. Application to photoacoustic cells of unconventional shape yields good agreement with experimental data.
TU Berlin, Inst.f.Math., Berlin
Zur effizienten Beschreibung akustischer Systeme werden oft sogenannte Netzwerkmodelle benutzt. Hierbei wird das Gesamtsystem in einzelne (einfache) Elemente zerteilt, die dann jeweils durch ihr eigenes Übertragungsverhalten charakterisiert sind. Besonders einfach lässt sich dieses Übertragungsverhalten darstellen, wenn zwischen den Elementen nur ebene Wellen ausbreitungsfähig sind.1 In ...
The Significance of Coupling in 3D Modelling of Acoustic Wave Propagation in a Cavity Containing Air and Porous Absorbent
L. Kelly, Y.W. Lam, and M. Avis
Research Institute for the Built and Human Environment, University of Salford
This study examines acoustic wave propagation in air and porous media in three dimensions using numerical models; in particular it looks at the significance of the coupling effect between the air and porous layer. The numerical model consist of a layer of air and a layer of porous absorbent which are modelled as equivalent fluid and are characterised by complex characteristic impedance based ...
S. Jeyaraman, B. Ganesan, and M. Kumar
GE Global Research, Bangalore
In this paper, a numerical model for time-domain ultrasound plane wave propagation for a desired angle is presented. The propagating angle is a function of the distance and the time-delay between the individual elements, and the propagating sound speed. In this model, the control parameter 'time' is used for steering the beam at the desired angle. We present an application of the proposed ...
M. Cobianchi and R. Magalotti
 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 ...
Guided Wave in Engineering Structures Using Non-Contact Electromagnetic Acoustic Transducers: A Numerical Approach for the Technique Optimisation
S. Soua, A. Raude, and T-H. Gan
NDT Technology Group, TWI Ltd, Cambridge, United Kingdom
There are over 10 million kilometers of pipes and pipelines around the world that carry hazardous fluids and gases. Fluids include oil, oil products, chemicals such as solvents, caustics, acids, corrosives and combustibles often at high pressure and temperature. These pipes are susceptible to corrosion if they are not protected properly by the environment or the contents. Inspection of pipes is ...