L. Melander , J. H. You ,
 University of St. Thomas, St. Paul, MN, USA
An acoustic energy harvesting system at low frequency (~200 Hz) using lead zirconate titanate (PZT) piezoelectric cantilever plates placed inside of a quarter-wavelength straight-tube resonator has previously been studied using COMSOL and verified experimentally. When an incident pressure wave at the resonator's eigenfrequency is introduced, an amplified acoustic resonant wave is developed that ...
T. G. Zielinski 
 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, ...
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 ...
M. Cobianchi, M. Rousseau
 B&W Group Ltd, Steyning, UK
While musical instruments often rely on a body which resonates on purposefully to amplify the vibration produced by a string or a membrane, such as in a violin or a guitar, loudspeaker cabinets should not contribute at all to the total sound radiation, but aim instead to be a perfectly rigid box which encloses the drive units in charge to transform the electrical signal at their terminal into ...
J. H. Lee , S. M. Al-Said ,
 American University of Sharjah, Sharjah, United Arab Emirates
 Jordan University of Science and Technology, Irbid, Jordan
In this paper, the effect of a crack to the flow-induced vibration characteristics of supported pipes is investigated based on vibration method. In order to estimate the crack location and depth in the pipe, we need to utilize the variation of the difference between the natural frequencies of the pipe conveying fluid with and without crack. The pipe is fluid loaded via interaction with the ...
F. Malbos , M. Bogdanski , M. Strauss ,
 Harman, Paris, France
 Harman Becker Automotive Systems, Straubing, Germany
For automotive applications, simulation methods are used to get the best audio acoustic performance. Because a loudspeaker is a non linear device, the sound pressure in the vehicle includes harmonics which are mainly created by the force factor, suspension stiffness and voice coil inductance of the loudspeaker. This paper shows how to simulate those non linear components using COMSOL ...
NEXO, Plailly, France
This paper describes the use of COMSOL Multiphysics® during the design of a vented box loudspeaker. Templates have been created to model the different needs of a complete design. Based upon those templates a box has been prototyped, measured and confronted to simulation. The cabinet may be described as a vented box design, featuring two low frequency drivers mounted in a "V Shape" with a horn ...
Fraunhofer Institute for Building Physics, Stuttgart, Germany
Bloch waves in infinite periodic structures – much in vogue in the present metamaterial age – can be conveniently studied by COMSOL Multiphysics® software. This is demonstrated by a simple, yet rich two-dimensional example: a perforated sheet with square symmetry. Instead of plane waves in homogeneous media, one has to deal with their generalizations: the Bloch waves. The frequencies of such ...
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 ...
R. Xu , M. Guizzetti , K. Astafiev , E. Ringgaard , T. Zawada ,
 Meggitt A/S, Kvistgaard, Denmark
FEM (Finite Element Method) modelling software such as COMSOL Multiphysics® can be a powerful tool for modelling the behavior and response of piezoelectric materials and devices . Devices based on piezoelectric crystals are particularly well suited, because the polarization magnitude in crystals is predetermined and its orientation is defined by how it was cut with respect to the lattice ...