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.

Acoustic Transparency of Non-homogeneous Plates (with repeating inclusions) using Periodic Structures Methodology

A. J. Kalinowski
Naval Undersea Warfare Center/Div. Npt. Newport, RI, USA

The paper addresses a class of problems for determining the acoustic interaction of time-harmonic plane waves impinging upon submerged elastic plates (fluid backed or void backed), that are infinite in extent.The plates can have repeated equally spaced inclusions (voids, solids, ribs etc.), and also can be constructed from orthotropic and/or isotropic layers that can have a frequency dependent ...

Nondestructive Testing of Composites Using Model Based Design

E. Nesvijski[1]
[1]ACOUSTICS@MBD CONSULTANTS, LLC, Westborough, MA, USA

There is a practical interest among composite materials manufacturers to high-speed accurate non-destructive evaluation (NDE) technology for voids inspection when these voids are natural components of such complex structures like resin insulated layer of double-sided copper-clad laminates. Model based design (MBD) of NDE system is one of principal solutions for voids inspection in such composites ...

Simulation of a Piezoelectric Loudspeaker for Hearing Aids and Experimental Validation - new

G. C. Martins[1], P. R. Nunes[1], J. A. Cordioli[1]
[1]Federal University of Santa Catarina, Florianópolis, SC, Brazil

The use of piezoelectric materials in hearing aid loudspeakers, also called receivers, presents technical and economic advantages such as reducing the number of parts of the system and its manufacturing cost. However, the performance of such systems is still not competitive when compared to traditional electrodynamic loudspeakers. In order to achieve an appropriate performance, one option is to ...

Modeling the response of photoacoustic gas sensors

S.L. Firebaugh[1], F. Roignant[2], and E.A. Terray[3]

[1]United States Naval Academy, Annapolis, Maryland, USA
[2]Polytechnique Nantes, Nantes, France
[3]Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA

A fast, high-sensitivity detector is required for studies of environmentally relevant gases. Photoacoustic spectroscopy (PAS), an absorption spectroscopy technique in which absorption is detected as sound, is explored as a possible solution. A tuning-fork based PAS sensor is modeled using COMSOL. The model combines the acoustic and piezoelectric modules and also includes viscous damping. The ...

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 ...

FEM Simulation of Generation of Bulk Acoustic Waves and their Effects in SAW Devices

A.K. Namdeo[1], N. Ramakrishnan[2], and H.B. Nemade[1]
[1]Department of Electronics and Communication Engineering, Indian Institute of Technology Guwahati, Guwahati, India
[2]Centre for Nanotechnology, Indian Institute of Technology Guwahati, Guwahati, India

This paper presents finite element method (FEM) simulation study of the generation of bulk acoustic waves (BAWs) and their effect on the performance of surface acoustic wave (SAW) devices, using COMSOL Multiphysics. A SAW delay line structure using YZ-cut lithium niobate substrate is simulated. The radiation of the bulk waves in all angles into the interior of the substrate is analyzed. The bulk ...

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 ...

Using COMSOL to Support a Cost-Effective, Non-Destructive Evaluation Approach for Predicting Bolt Failure in Highway Bridges

A. Elyea, B. Doubek, G. Hubbard, and D. Ozevin
Department of Civil Engineering
University of Illinois at Chicago
Chicago, IL

The development of a quantitative nondestructive evaluation method, as an alternative to visual inspection, for inspecting pre-tensioned bolts in fracture critical bridges is presented. In order to understand the ultrasonic behavior of a wide variety of bolt geometries used in bridges, numerical models of nine different bolt geometries were developed. The numerical models included the ...

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 ...

Transient Heat Transfer Effects from a Flapping Wing

Lind, R.J., Abedian, B.
Department of Mechanical Engineering Tufts University, Medford, Massachusetts

This presentation is a numerical study of fluid flow around a two-dimensional rigid flapping plate and its effects on the resultant transient heat transfer effects on the solid interface. In this study, a flat inflexible thin plate surrounded by air undergoes sinusoidal angular motion from one end while the other end is kept stationary, simulating a flapping motion. The two-dimensional ...

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