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.

Effects Of The Microstructure Of Fibrous Media On Their Acoustic Properties

C. Peyrega, and D. Jeulin
Center of Mathematical Morphology, Mines ParisTech, Fontainebleau, France

This study is a part of the Silent Wall ANR project, to which the Center of Mathematical Morphology is associated. Its main objective is to build an acoustical and thermal insulating system for buildings, composed of fibrous materials. The material is composed of two phases: the fibrous network and the air surrounding it. At the microscopic scale the absorption of the acoustic wave is mainly due ...

Numerical Study on Shear Horizontal Electromagnetic Acoustic Transducers for Generation of Ultrasonic Guided Waves for Absorber Tubes used in Concentrated Solar Plants

L. Cheng[1], A. Mohimi[1], M. Kogia[1], V. Kappatos[1], C. Selcuk[1], T.-H. Gan[1]
[1]Brunel Innovation Centre, Brunel University, Uxbridge, UK

Absorber tubes are one of the most critical components of parabolic trough Concentrated Solar Plants, which is very likely get damaged such as crack and mass loss. Therefore, the monitoring of their structural health via Non-Destructive Testing (NDT) techniques is regarded as essential for preventing them from being significantly defective and thereby reducing maintenance cost. Non-contact ...

Numerical Shape Optimization of Photoacoustic Sample Cells: First Results

B. Baumann1, B. Kost1, M. Wolff1,2, H. Groninga2, T. Blöß1, and S. Knickrehm1
1Hamburg University of Applied Sciences, Hamburg, Germany
2PAS-Tech GmbH, Zarrentin, Germany

First results in the automatic shape optimization of a photoacoustic sample cell are described. The aim is to maximize the sensor’s signal strength. The approach considers all shapes that can be represented by a number of axis-symmetrical truncated cones which are connected in a continuous way. In addition, the cell is subjected to certain constraints (e.g. the laser beam is not blocked during ...

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 ...

A Study of the Acoustic Response of Carbon Fiber Reinforced Plastic Plates

J. O'Donnell, and G. McRobbie
University of the West of Scotland
Paisly, United Kingdom

This paper gives an introduction to a continuing study detailing the process and development of using both experimental and Finite Element Analysis to characterise the acoustic response of a Carbon Fiber Reinforced Plastic (CFRP) laminate plate provided by a guitar manufacturer. The results show that there is a strong correlation between both the experimental and simulated data which gives the ...

Modeling an electric cell actuator and loudspeaker using COMSOL Multiphysics

W. J. Wu
NTU Nano-Bio MEMS Group
National Taiwan University,
Taiwan

This presentation presented the following: * The building of an FEA model of an electric cell actuator using COMSOL Multiphysics * Validation of this model through the AVID and ESPI measurement systems * The building of an FEA model of an electric loudspeaker using COMSOL Multiphysics * Validation of this model throughan acoustic measurement systems This paper is in Chinese.

Modeling Low Frequency Axial Fluid Acoustic Modes in Continuous Loop Piping Systems

E. Gutierrez-Miravete[1], E.R. Marderness[2]
[1]Rensselaer Polytechnic Institute, Hartford, CT, USA
[2]General Dynamics-Electric Boat, Groton, CT, USA

Industrial fluid systems often involve continuous piping loops. These systems consist of varying lengths of pipes and hoses connecting multiple components together. Fluid resonances can detrimentally affect the operation of fluid systems and components. This work used COMSOL to investigate the frequency and mode shapes of axial fluid resonances within a system of piping and components that form ...

Mean Flow Augmented Acoustics in Rocket Systems

S. Fischbach[1]
[1]NASA Marshall Space Flight Center / Jacobs ESSSA Group, Huntsville, AL, USA

Combustion instability in solid rocket motors and liquid engines has long been a subject of concern. Recent advances in energy based modeling of combustion instabilities require accurate determination of acoustic frequencies and mode-shapes. Of particular interest is the acoustic mean flow interactions within the converging section of a rocket nozzle, where gradients of pressure, density, and ...

Sound Field Analysis of Monumental Structures by the Application of Diffusion Equation Model

Z. S. Gul[1], N. Xiang[2], M. Caliskan[3]
[1]Department of Architecture, Middle East Technical University, Ankara, Turkey
[2]School of Architecture, Rensselaer Polytechnic Institute, Troy, NY, USA
[3]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 structure ...

Sound Attenuation by Hearing Aid Earmold Tubing

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.

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