Technical Papers and Presentations

Here you will find presentations given at COMSOL Conferences around the globe. The presentations explore the innovative research and products designed by your peers using COMSOL Multiphysics. Research topics span a wide array of industries and application areas, including the electrical, mechanical, fluid, and chemical disciplines. Use the Quick Search to find presentations pertaining to your application area.

Identification of Noise Sources by Means of Inverse Finite Element Method

M. Weber[1], T. Kletschkowski[1], and B. Samtleben[2]
[1]Helmut-Schmidt-University Hamburg, Germany
[2]Airbus 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 ...

Structured Ultrasonic Metasurfaces

R. C. Thiagarajan
ATOA Scientific Technologies Private Limited
Bangalore, India

Ultrasonic acoustic waves usually encounter interfaces with significant impedance mismatch in practical medical or industrial imaging applications. A transparent interface can help to improve the performance of medical and industrial imaging and overall innovative applications. Similarly, a broadband total reflection interface can help to improve the architectural or transportation barrier ...

Calibration of Ultrasonic Testing for Faults Detection in Stone Masonry

M. Usai[1], S. Carcangiu[1], G. Concu[2]
[1]Department of Electrical and Electronic Engineering, University of Cagliari, Cagliari, Italy
[2]Department of Civil Engineering, Environmental and Architecture, University of Cagliari, Cagliari, Italy

In the field of assessment methodologies, particular importance is given to Non-Destructive Testing Techniques, which aspire to achieve the highest number of information about materials and structures without altering their condition. Ultrasonic Testing exploits the transmission and reflection characteristics of mechanical waves with appropriate frequencies passing through the investigated item. ...

Wave Carpet Simulation using Coupled Hydro-elastic FEMLAB Model

Ibragimov A., Koola, P.M.
Texas Tech University, Mathematics and Statistics, Lubbock TX, BSI One KBSI Place, East University, TX

Wave Carpet is a novel deep offshore wave-power floating system concept funded by the Office of Naval Research that will have low overall life cycle cost due to an integrated design and be rapidly redeployable. In this paper we numerically model the Wave Carpet motion using a coupled hydro-elastic time-domain solution. The major feature of the mathematical model is the presence of non ...

Electro-acoustic Coupling in Nematic Liquid Crystals

G. Rosi[1], L. Teresi[1], A. DiCarlo[1], and F. dell'Isola[2]
[1]LaMS - Università degli Studi Roma Tre, Roma, Italy
[2]Università degli Studi di Roma "La Sapienza", Roma, Italy

Liquid crystals - as all liquids - are generally modelled as incompressible media. In fact, mass-density changes occurring in these mesophases are minuscule and inconsequential in most regimes of interest. However, liquid crystals exhibit also phenomena that call for a more refined theory. In particular, it is experimentally well established that the Fréedericksz transition - i.e., the sudden ...

Designing Materials for Mechanical Invisibility Cloaks

P. Olsson[1], F. Larsson[1], A. Khlopotin[1], S. Razanica[1]
[1]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 ...

Acoustic-Structure Interaction Modeling of Piezoelectric Transducer in Fluid Medium

V.M. Acosta[1], E. Riera[1], G. Rodriguez[1], A. Pinto[1], A. Cardoni[2], J.A. Gallego-Juárez[1]
[1]Power Ultrasonics Group, CSIC, Serrano, Madrid, Spain
[2]Pusonics, Arganda del Rey, Madrid, Spain

This work describes the design methodology and development of piezoelectric transducers for applications in fluids with COMSOL_Multiphysics. In these linear models for the acoustic-structure interaction approximate numerical solutions have been obtained. In order to perform the calculations, simplifications are only valid for low-power sound waves. Numerical modeling of piezoelectric transducers ...

Vibration and Acoustic Analysis of a Trussed Railroad Bridge under Moving Loads

R. Costley[1], H. Diaz-Alvarez[1], M. McKenna[1], A. Miller[1]
[1]U.S. Army Engineer Research and Development Center, Vicksburg, MS, USA

Two finite element models have been developed to investigate the acoustic radiation from a Pratt truss train bridge. The first model was a time dependent structural model that determined the vibration response of the structure due to two wheels, representing a single axle, moving across the bridge at constant speed. This model was expanded to include multiple axles to represent a locomotive. The ...

Near-Wall Dynamics of Microbubbles in an Acoustical Trap - new

L. Wright[1], G. Memoli[1], P. Jones[2], E. Stride[3]
[1]National Physical Laboratory, Teddington, UK
[2]University College London, London, UK
[3]University of Oxford, Oxford, UK

Understanding the interactions between microbubbles and surfaces is key to the successful deployment of microbubbles in a range of applications. Two important examples are their use as a drug delivery mechanism, and their potential use of acoustically-driven bubbles as microscale sensors. Drug delivery with bubbles involves sonication at high frequency close to a boundary, and sensing with ...

Towards a Finite Element Calculation of Acoustical Amplitudes in HID Lamps

B. Baumann[1], M. Wolff[1], J. Hirsch[2], P. Antonis[2], S. Bhosle[3], and R. Valdivia Barrientos[4]
[1]Hamburg University of Applied Sciences, Hamburg, Germany
[2]Philips Lighting, Eindhoven, The Netherlands
[3]LAPLACE, Université de Toulouse and CNRS, Toulouse, France
[4]National Institute of Nuclear Research, Salazar, Ocoyoacac, Mexico

High intensity discharge lamps can experience flickering and even destruction, when operated at high frequency alternating current. The cause of these problems has been identified as acoustic resonances inside the lamp’s are tube. Here, a finite element approach for the calculation of the acoustic response function is described. The developed model does not include the plasma dynamics.

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