D. Borelli and C. Schenone
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 ...
M. Weber, T. Kletschkowski, and B. Samtleben
Helmut-Schmidt-University Hamburg, Germany
An inverse finite element method for noise source identification in an aircraft cabin is presented. If all sound sources are located on the boundary of the cabin, the equation system resulting from a matching FE model can be re-sorted in such a way that computation of the unknown boundary data is possible from measurement data taken in the cavity. The method is first validated using a simplified ...
Beam Structure As an Acoustic Wave Sensor: A Study of the Effect of Sensor Design on Its Sensitivity to Noise
F. Akasheh, A. Biddle, W.S. Shepard Jr., and B.B.B. Zhang
Tuskegee University, Tuskegee, AL, USA
University of Alabama, Tuscaloosa, AL, USA
The detection and identification of the location of a sound source is commonly done using arrays of microphones. A recent new alternative approach has been proposed which involves the use of continuous structures, such as beams or plates, as acoustic wave sensors. The sound wave impinging on the surface of the structure causes it to vibrate and the measured surface displacements can then be used ...
ACOUSTICS@MBD CONSULTANTS, LLC, Westborough, MA, USA
There is a practical interest among composite materials manufacturers to high-speed accurate non-destructive evaluation (NDE) technology for voids inspection when these voids are natural components of such complex structures like resin insulated layer of double-sided copper-clad laminates. Model based design (MBD) of NDE system is one of principal solutions for voids inspection in such ...
J. Soons[1,2], C. Steele, S. Puria
Lab of Biomedical physics, University of Antwerp, Antwerp, Belgium
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 ...
L. Martinelli, and A. Lamberti
Universita di Bologna, Italy
Objective of this contribution is to show how to implement the Mild Slope Equations with COMSOL Multiphysics. These equations are commonly used to study the propagation of waves in harbors. Some interesting features are presented, namely the use of weak terms (used for the modelling of the source term); the evaluation of a smooth phase gradient from the complex dependent variable; a robust ...
A-S.Moreau, H.Lissek, and F. Bongard
Ecole Polytechnique Fédérale de Lausanne, Switzerland
JAST SA, Antenna Systems, Lausanne, Switzerland
In this context, a one-dimensional acoustic transmission line, exhibiting metamaterial properties, is presented. It is composed of an acoustic waveguide, periodically loaded with membranes having the function of series capacitances, as well as transversally connected open channels (denoted stubs) having the function of shunt inductances. A validation of the transmission line design is made ...
A Study into the Acoustic and Vibrational Effects of Carbon Fiber Reinforced Plastic as a Sole Manufacturing Material for Acoustic Guitars
J. O'Donnell, G. McRobbie
University of the West of Scotland, Paisley, Scotland, United Kingdom
This study will research a modern design of acoustic guitar by analysis of the vibrational modes. The guitar that will undergo testing has been provided by Emerald Guitars and is solely constructed using Carbon Fiber Reinforced Plastic (CFRP). With the use of COMSOL Multiphysics© the soundboard of the guitar will be simulated and analysis will be carried out to determine the first 10 ...
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 ...
L.B.M. Silva, E.J.P. Santos
Laboratory for Devices and Nanostructures, Electronics and Systems Department, Universidade Federal de Pernambuco, Recife, PE, Brasil
Transducer optimization is a key aspect for successful development and deployment of advanced sensors, especially when designing 3D structures for harsh environments. For piezoelectric transducers, plate thickness determines the operating frequency of the resonator, which is frequently tuned in the shear thickness vibration mode. Quartz has been the material of choice for the fabrication of ...