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.

A Study into the Acoustic and Vibrational Effects of Carbon Fiber Reinforced Plastic as a Sole Manufacturing Material for Acoustic Guitars

J. O'Donnell[1], G. McRobbie[1]
[1]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 ...

Modeling of a Jecklin Disk for Stereophonic Recordings

G. McRobbie[1]
[1]University of the West of Scotland, Paisley, Renfrewshire, UK

The Jecklin Disk is a sound absorbing disk placed between two omnidirectional microphones. It is used to recreate some of the frequency-response, time and amplitude variations human listeners’ experience, but in such a way that the recordings also produce a useable stereo image through loudspeakers. This paper presents a finite element model able to simulate the effects on sound propagation ...

Lamb Waves in Fluid-Loaded Plates

T. Kaufmann[1], F. Kassubek[1], D. Pape [1], M. Lenner[1]
[1]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 ...

Design of Electroacoustic Absorbers Using PID Control

H. Lissek, R. Boulandet, and M. Maugard
Ecole Polytechnique Federale de Lausanne
Lausanne, Switzerland

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 ...

Feed-forward/Feed-backward Mechanical Amplification in the Mouse Cochlea

J. Soons[1,2], C. Steele[2], S. Puria[2]
[1]Lab of Biomedical physics, University of Antwerp, Antwerp, Belgium
[2]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 ...

Numerical Vibration Analysis of Impacted CFRP Specimens Using COMSOL Multiphysics® Software

P. Jatzlau [1], F. Seybold [1], C. Grosse [1],
[1] 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, ...

Acoustic Wave Crack Detection: A First Principles Approach

R. W. Pryor [1],
[1] Pryor Knowledge Systems, Inc., Bloomfield Hills, MI, USA

Crack detection is and has been an active field of exploration, both theoretical and applied for a number of years. It is the belief of this author that the concepts presented herein explore a new methodology for the modeling and the detection of cracks and families of cracks in crystalline solids, polycrystalline solids and high viscosity amorphous materials (glasses). In the case of the ...

Analysis of High-Frequency Thermoacoustic Instabilities in Lean, Premixed Gas Turbine Combustors

F. Berger [1], T. Hummel [1], P. Romero [1], M. Schulze [1], B. Schuermans [2], T. Sattelmayer [1],
[1] Lehrstuhl für Thermodynamik, TU München, Germany
[2] 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 ...

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

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 ...

Increasing Heat Transfer in Microchannels with Surface Acoustic Waves - new

S. Berry[1]
[1]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 ...