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 ...
M. Herring Jensen
Widex A/S, Vaerloese, Denmark
In this study we model the sound attenuation properties of a hearing aid earmold tube. The model includes thermoviscous acoustic effects and it couples structural vibrations to the external acoustic field. Moreover, the finite element domain is coupled at two boundaries with an electroacoustic model of a hearing aid and an acoustic 2-cc coupler.
P. Olsson, F. Larsson, A. Khlopotin, S. Razanica
Chalmers University of Technology, Gothenburg, Sweden
In solid mechanics, there is considerable interest in achieving “invisibility”. The applications in mechanics include protection of structures and parts of structures from potentially harmful transient waves and steady state vibrations. A suggested large scale application is that protection against seismic waves from earthquakes could be achieved by using cloaking to re-route the waves around ...
H. Chen , J. Li , S. Xia ,
 Hunan University, Changsha, Hunan, China
 Xi'an Jiaotong University, Xi'an, Shaanxi, China
Introduction In order to understand the detection mechanism of the PZT based nondestructive testing (NDT) technology for interface debonding of CFSTs, numerical simulation on a multi-physical model composed of surface-mounted PZT patches and CFST structural member is established in COMSOL Multiphysics®. The stress propagation process and the electrical signal output of an embedded PZT patch as ...
H. Lissek, R. Boulandet, and M. Maugard
Ecole Polytechnique Federale de Lausanne
An \"electroacoustic absorber\" is a loudspeaker, used as an absorber of sound, which acoustic impedance can be varied by electrical means. This can be achieved either by plugging passive shunt electric networks at the loudspeaker terminals (“shunt loudspeakers”) or by feeding back the loudspeaker with a voltage proportional to acoustic quantities, such as sound pressure and diaphragm normal ...
Karthi Pradeep, G. Suresh, V. Natarajan,
National Institute of Technology, Tiruchirappalli, Kerala, India
Naval Physical & Oceanographic Laboratory (NPOL), Kochi, Kerala, India
A Helmholtz resonator type acoustic sensor has been designed using analytical method and finite element modeling software, COMSOL Multiphysics®. The acoustic sensor is an aluminium double frustum, hour glass, shaped with the resonator at the bottom and an acoustic horn above to amplify the incoming acoustic signal. The horn provides a broad amplification of the incoming acoustic signal while the ...
D. Neihguk , M. L. Munjal , A. Prasad ,
 Mahindra & Mahindra Ltd, Chennai, India
 Indian Institute of Science, Bangalore, India
Perforated pipes are extensively used to control exhaust noise in automobiles [1-4]. The energy loss associated with the perforations leads to back pressure which needs to be quantified and minimized . An objective approach presented in  is the introduction of friction factor for perforated ducts as a function of the porosity. In this article, the utilization of the CFD Module of COMSOL ...
T. H. Hanley, H. T. D. Grigg, B. J. Gallacher
Newcastle University, Newcastle-Upon-Tyne, UK
Introducing a disorder into a finite periodic oscillatory system induces the presence of a 'trapped mode': a mode in which the displacement field is localised to the region of the disorder. A main inhibitor to MEMS resonators achieving a high quality (Q) factor is energy radiation through the support to the substrate. The trapped modes present a way to tune this to a minimal value. An initial ...
C. R. Pérez , J. J. Santiago-Avilés ,
 Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA, USA
 Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA, USA
Sensorineural hearing loss is the most common sensory deficit in the world, and within this category damage or loss of the primary sensory cells of the inner ear, known as hair cells is the most common cause . Partial hearing loss is addressed by the use of hearing aids, electronic devices that greatly amplify sound directly into the user's ear, but for more severe cases cochlear implants are ...
V. Romero-García, A. Krynkin, J.V. Sánchez-Pérez, S. Castiñeira-Ibáñez, and L.M. Garcia-Raffi
Centro de Tecnologías Físicas Acústica, Universidad Politécnica de Valencia, Valencia, Spain
School of Computing, Science & Engineering, University of Salford, Salford, United Kingdom
Depto. Física Aplicada, Universidad Politécnica de Valencia, Valencia, Spain
Instituto Universitario de Matemática Pura y Aplicada, Universidad Politécnica de Valencia, Valencia, Spain
The elastic and geometrical properties of Low Density Polyethylene (LDPE) foam are used in this paper to improve the attenuation properties of periodic arrangements of acoustic scatterers known as Sonic Crystals (SCs). A specific recycled profile of LDPE foam is used as elastic-acoustic scatterer. The acoustic spectrum of the single scatterer shows two attenuation peaks in the low frequency ...