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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.

Simulation of Helmholtz Resonators for Optical Gas Sensing: Comparison Between Pressure Acoustics and Thermoacoustics - new

B. Parvitte[1], C. Risser[1], R. Vallon[1], V. Zéninari[1]
[1]Université de Reims, Reims, France

Among optical gas sensing methods, photoacoustic (PA) spectroscopy combined with a laser source has proven to be a very robust and sensitive method for trace gas detection. COMSOL Multiphysics® software was used to calculate the frequency response of differential Helmholtz resonator cells in order to optimize the detection limit of PA sensors. Two different kind of simulation were performed: ...

Support-Q Optimisation of a Trapped Mode Beam Resonator - new

T. H. Hanley[1], H. T. D. Grigg[1], B. J. Gallacher[1]
[1]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 ...

Improving the Performance of Hearing Aids Using Acoustic Simulations

Mads Jakob Herring Jensen
Dr., Widex A/S, Denmark

In modern hearing aids, the performance of directional microphone systems is dependent on both the acoustics around thehearing aid and on the specific signal processing algorithms. The sound pressure at the microphone inlets depends on microphone location in the hearing-aid shell, the inlet shape, and on the placement of the hearing aid on the head of the user. In the present work, the ...

Accuracy of Fully Coupled Loudspeaker Simulation Using COMSOL

M. Hedges[1][2] and Y.W. Lam[1]
[1]Acoustics Research Centre, School of Computing, Science & Engineering, University of Salford, Salford, United Kingdom
[2]Monitor Audio Ltd., Rayleigh, Essex, United Kingdom

Loudspeaker simulation is used to inform the designer as to the performance of a design. In recent years the Finite Element Method (FEM) has been used to model the mechanical and acoustical attributes of a loudspeaker with varying success. This paper shows how a model that incorporates the magnetic, electromagnetic, mechanical and acoustical domains performs. These domains will be coupled where ...

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 ...

Beam Structure As an Acoustic Wave Sensor: A Study of the Effect of Sensor Design on Its Sensitivity to Noise

F. Akasheh[1], A. Biddle[1], W.S. Shepard Jr.[2], and B.B.B. Zhang[2]
[1]Tuskegee University, Tuskegee, AL, USA
[2]University of Alabama, Tuscaloosa, AL, USA

The detection and identification of the location of a sound source is commonly done using arrays of microphones. A recent new alternative approach has been proposed which involves the use of continuous structures, such as beams or plates, as acoustic wave sensors. The sound wave impinging on the surface of the structure causes it to vibrate and the measured surface displacements can then be used ...

Quartz Transducer Modeling for Development of BAW Resonators

L.B.M. Silva[1], E.J.P. Santos[1]
[1]Laboratory for Devices and Nanostructures, Electronics and Systems Department, Universidade Federal de Pernambuco, Recife, PE, Brasil

Transducer optimization is a key aspect for successful development and deployment of advanced sensors, especially when designing 3D structures for harsh environments. For piezoelectric transducers, plate thickness determines the operating frequency of the resonator, which is frequently tuned in the shear thickness vibration mode. Quartz has been the material of choice for the fabrication of bulk ...

Computational Modeling of Wave Propagation in a Geophysical Domain

J. McKenna[1], M. McKenna[1], S. Yushanov[2], J. Crompton[2], and K. Koppenhoefer[2]
[1]U.S. Army Engineering Research and Development Center
[2]ACES of Columbus, LLC, Columbus, OH, USA

The propagation of shear (S) and compression (P) waves within the earth allows geologists to track seismic events and to identify subterranean structure. This work shows the strong effect of including the variation of wave speed through the top thirty meters of the earth. By including this variation in material properties, the wave arrival time and frequency content agree with experimental ...

Acoustic Emission Simulation for Online Impact Detection

C. Yang, M. A. Torres-Arredondo, and C.-P. Fritzen
Institute of Mechanics and Control Engineering
Mechatronics
University of Siegen
Siegen, Germany

Impact monitoring has been extensively studied by several researchers and it has been shown that damage extent can be correlated with the impact magnitude. In order to make the process cost-effective, simulation of the impact has been performed, to get the big training data set from modeling. The structural dynamic responses captured by PZT transducers due to impact events are recorded from ...

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 ...