T. Kaufmann, F. Kassubek, D. Pape , M. Lenner
ABB Corporate Research, Baden-Dättwil, Switzerland
Lamb waves are elastic waves propagating in free solid plates. In the case of plates loaded with a fluid, the equations describing these waves have to be modified to include the effects of the fluid. In our work we have tackled this problem using COMSOL Multiphysics®. We have used the two-dimensional plane strain model of the solid mechanics interface to calculate the eigenmodes of the coupled ...
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 ...
M. A. B. Andrade , N. Pérez , J. C. Adamowski ,
 Instituto de Física, Universidade de São Paulo, São Paulo, SP, Brasil
 Centro Universitario de Paysandú, Universidad de la República, Paysandú, Uruguai
 Departamento de Engenharia Mecatrônica e Sistemas Mecânicos, Escola Politécnica, Universidade de São Paulo, São Paulo, SP, Brasil
Este trabalho apresenta a simulação numérica de um sistema de levitação acústica para manipulação de partículas em ar. O sistema de levitação consiste de dois transdutores de ultrassom e um refletor de face plana. Através da simulação é calculado o potencial da força de radiação acústica que atua numa esfera. Os resultados da simulação são verificados experimentalmente através da comparação da ...
F. Berger , T. Hummel , P. Romero , M. Schulze , B. Schuermans , T. Sattelmayer ,
 Lehrstuhl für Thermodynamik, TU München, Germany
 GE Power, Switzerland
Modern gas turbine systems for power generation are prone develop so-called thermosacoustic instabilities in the combustion chamber. Physically, these instabilities emerge as large amplitude pressure oscillations within the combustor, which are caused by constructive feedback interactions between the flame and the combustor's natural acoustic modes. The oscillations disturb the combustion ...
Z. S. Gul, N. Xiang, M. Caliskan
Department of Architecture, Middle East Technical University, Ankara, Turkey
School of Architecture, Rensselaer Polytechnic Institute, Troy, NY, USA
Department of Mechanical Engineering, Middle East Technical University, Ankara, Turkey
Sound energy distribution patterns within enclosed spaces are the basic concerns of architectural acoustics. Energy decays are analyzed for major acoustical parameter estimations, while spatial energy distribution and flow vectors are indicative in the analysis of sound energy circulation and concentration zones. In this study the acoustical field of a real-size multi-domed monumental ...
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 ...
I .F. Melikhov , A. S. Amosov , S. A. Chivilikhin ,
 Corning Scientific Center, Saint Petersburg, Russia
 ITMO University, Saint Petersburg, Russia
Ultrasonic levitation is a novel technology for contactless handing of various objects. It is already used in various manufacturing processes where it is important to keep untouched surface. In this paper we introduce a model of so-called near-field ultrasonic levitation which allows flying heights of the hundred-micron order. Our model computes air flow in the gap between a vibration source and ...
P. Jatzlau , F. Seybold , C. Grosse ,
 Technical University of Munich, Chair of Non-destructive Testing, Munich, Germany
The vibration behavior of carbon fiber reinforced composites (CFRP) specimens with impact damage is presented in order to evaluate if an before/after modal analysis can be used as a non-destructive testing method to detect delaminations. The impact damage is modeled by decreasing the stiffness in the described area of delamination. As detailed experimental data exists for the modeled structure, ...
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 ...
Massachusetts Institute of Technology: Lincoln Laboratory, Lexington, MA, USA
In this numerical study, surface acoustic waves (SAWs) are evaluated as a potential disruptive flow technology for enhancing heat transfer in microchannels. Using COMSOL Multiphysics® software, the physics governing acoustics, single-phase-fluid flow and heat transfer are coupled. The results show that acoustic streaming can disrupt the bulk fluid flow, creating rotating vortices within the ...