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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.

Linear Water Wave Propagation around Structures

L. Martinelli, and A. Lamberti
Universita di Bologna, Italy

Objective of this contribution is to show how to implement the Mild Slope Equations with COMSOL Multiphysics. These equations are commonly used to study the propagation of waves in harbors. Some interesting features are presented, namely the use of weak terms (used for the modelling of the source term); the evaluation of a smooth phase gradient from the complex dependent variable; a robust ...

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 ...

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 ...

Application of COMSOL to Acoustic Imaging

K. Mcilhany, and J.C Hernandez
U.S. Naval Academy, Annapolis, MD, USA

Acoustic Imaging of hand movement is being studied with COMSOL and Matlab. A hardware implementation is being pursued that will be an array of 16x16 ultra-sonic speakers placed in a grid facing a similar grid of 16x16 microphones, operating at 40kHz. COMSOL is used to repeatedly calculate the diffraction pattern from a small scattering center, approximately 1.0cm in diameter. In conjunction ...

Mathematical Model for Prediction of Transmission Loss for Clay Brick Walls

J. Ratnieks[1], A. Jakovics[1], J. Klavins[1]
[1]Laboratory for Modeling Technological and Environmental Processes, University of Latvia, Riga, Latvia

A 2D numerical model for determination of sound reduction index is set up in this work. Results are in good agreement in middle and high frequency range when using solid structure approximation. Results are compared with experiment.

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. ...

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 ...

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 ...

Comsol’s New Thermoviscous Interface and Computationally Efficient Alternative Formulations for FEM

W. R. Kampinga[1], and Y. H. Wijnant[2]
[1]Reden, Hengelo, Netherlands
[2]University of Twente, Enschede, Netherlands

Three efficient alternatives to the model in COMSOL’s thermoacoustics interface are presented. The higher efficiency of these models are explained from theory and are demonstrated by means of two examples.

Cloud Computations for Acoustics with Coupled Physics - new

A. Daneryd[1], D. Ericsson[2]
[1]ABB Corporate Research, Västerås, Sweden
[2]COMSOL AB, Stockholm, Sweden

For certain classes of scientific and technical computations the cloud may offer easily accessible, scalable, and affordable gigantic computing power. A power that for these classes may lead to a step change in model and analysis complexity compared to what is feasible with dedicated clusters and similar networked solutions. Acoustics with or without interaction with coupled physics fields ...