C. Thiagarajan, Gururajan R., A. H. Baig, Prema S.
ATOA Scientific Technologies Pvt Ltd, Whitefield, Bangalore, Karnataka India
University of Southern Queensland, Toowoomba Qld 4350, Australia.
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 ...
H. Bruus, P.B. Muller, R. Barnkob, M.J.H. Jensen
Technical University of Denmark, Kongens Lyngby, Denmark
COMSOL, Kongens Lyngby, Denmark
We have simulated the ultrasound-induced acoustophoretic motion of microparticles suspended in an aqueous solution. The full first-order thermoviscous acoustics equations have been implented on a rectangular microfluidic 2D domain excited with an ultrasound field tuned to resonance near 2 MHz. The micrometer-thin but crucial viscous boundary layers at the rigid walls have been fully resolved. The ...
A. Cavuto, G.M. Revel , M. Martarelli , F. Sopranzetti 
Università Politecnica delle Marche, Ancona, Italy
Università e-Campus, Novedrate (CO), Italy
A 2D axisymmetric model was considered in order to evaluate the propagation paths of the ultrasonic waves generated inside an aluminum plate sample due to a rapid thermal expansion produced by laser pulse. Laser Doppler Vibrometer is used to experimentally validate the numerical results of the wave propagation in the material. The presented numerical model is able to identify directivity patterns ...
A. Ravi, R. Krishna, J. Christen
Arizona State University, Tempe, AZ, USA
Capacitive MEMS sensors offer high spatial resolution, sensitivity and good frequency response. In this paper, we present a circular membrane capacitive MEMS device that finds use both as capacitive micromachined ultrasonic transducer (CMUT) and pressure sensor. The MEMS device is first designed and simulated to work as a CMUT operating at about 5 MHz frequency. The device can also function as a ...
Zhejiang Electro-Acoustic R&D Center, CAS, Zhejiang, China
扬声器的失真问题一直受电声业界的关注，尤其是谐波失真，它是影响扬声器重放声音音质的主要因素之一。 本文提出了一种基于 COMSOL Multiphysics® ...
Dynamic Characterization and Mechanical Simulation of Cantilevers for Electromechanical Vibration Energy Harvesting
N. Alcheick, H. Nesser, H. Debeda, C. Ayela, I. Dufour 
Univ. Bordeaux, IMS Lab, Pessac, France
Energy harvesting from ambient vibrations has become an interesting topic for powering wireless sensor networks. Resonant microdevices based on MEMS have become of central importance at low frequency. The power produced at resonance is at least one order of magnitude larger than off frequency power since the largest strain is obtained at resonance. In order to obtain large strain for efficient ...
Teledyne Technologies Inc., Falmouth, MA, USA
This paper describes the COMSOL Multiphysics® simulation and the test of a low-frequency (500Hz) sound source for long-range acoustic communications. This design uses innovative carbon-fiber composite materials.To meet the demand for the frequency range the doubly resonant organ pipe resonator was suggested. A multi-resonant system usually needs a precise, complicated adjustment of its ...
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 ...
Dinex Emission Technology A/S, Middelfart, Denmark
Exhaust noise must meet legislation targets, customer expectations and cost reduction which call for design optimization of the exhaust systems in the design phase. One solution is to use 3 dimensional linear pressure acoustics and calculate the transfer matrix of the muffler. The transfer matrix is the basis for calculating either the insertion loss or transmission loss of a muffler. The 3D ...
Multiphysics Modelling of Sound Absorption in Rigid Porous Media Based on Periodic Representations of Their Microstructural Geometry
Institute of Fundamental Technological Research, Polish Academy of Sciences, Warsaw, Poland
Sound absorption in porous materials with rigid frame and open porosity can be very effectively estimated by applying the Johnson-Allard model in order to substitute a porous medium with an equivalent effective fluid and then utilise the Helmholtz equation for time-harmonic acoustics. The model uses several parameters which characterize the micro-geometry of porous material from the macroscopic ...