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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.

Acoustic Attenuation Performance Of Helicoidal Resonator Due To Distance Change From Different Cross-Sectional Elements Of Cylindrical Duct

W. Łapka
Poznań University of Technology, Poznań, Poland

This work presents acoustic attenuation performance of helicoidal resonator due to distance change from different cross-sectional elements of cylindrical duct. The helicoidal resonator properties are described mainly in in infinite long cylindrical duct. For practical applications it is important to know the limits of use of this solution. This paper describes how the helicoidal resonator should ...

Modelling the Wall Vibrations of Brass Wind Instruments

V. Chatziioannou, and W. Kausel
Institute of Music Acoustics
University of Music and Performing Arts
Vienna, Austria

The vibration of the walls of brass wind instruments has been a subject of study in the field of musical acoustics throughout the last decades. The amplitude of such vibrations, stimulated by the oscillating air pressure inside the instrument bore, is very small compared to the dimensions of the instrument. However, it has been recently shown that at the flaring regions of the bell of brass ...

Designing a Smart Skin with Fractal Geometry

S. Ni, C. Yang Koh, S. Kooi, and E. Thomas
Institute for Soldier Nanotechnologies
Dept. of Materials Science and Eng.
Cambridge, MA

Recently, the concepts of fractal geometry have been introduced into electromagnetic and plasmonic metamaterials. With their self-similarity, structures based on fractal geometry should exhibit multi-band character with high Q factors due to the scaling law. However, there exist few studies of phononic metamaterials having fractal geometry. COMSOL is used to investigate vector elastic and ...

Empirical Model Dedicated to the Sensitivity Study of Acoustic Hydrogen Gas Sensors Using COMSOL Multiphysics®

A. Ndieguene[1], I. Kerroum[1], F. Domingue[1], A. Reinhardt[2]
[1]Laboratoire des Microsystèmes et de Télécommunications/Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
[2]Laboratoire d’Électronique et des Technologies de l’Information, CEA, LETI Grenoble, France

Due to the increasing demand for hydrogen gas sensors for applications such as automation, transportation, or environmental monitoring, the need for sensitive and reliable sensors with a short response time is increasing. This paper presents an empirical model that studies the sensitivity of acoustic hydrogen gas sensors. A parametric study based on the variation of physical properties of ...

Two- and Three-Dimensional Holey Phononic Crystals with Unit Cells of Resonators

Y.F. Wang[1][2], Y.S. Wang[1], L. Wang[2]
[1]Institute of Engineering Mechanics, Beijing Jiaotong University, Beijing, China
[2]Department of Mechanical Engineering, Østfold University College, Halden, Norway

We show in this paper that by careful design of the geometry of the resonators, complete bandgap with relatively low center frequency can be obtained for 2D and 3D Phononic Crystals with resonators. The generation of the bandgap is due to the local resonance of the unit cell. Spring-mass and spring-pendulum models are developed to predict the boundaries of the complete bandgap. The predicted ...

Vibration Analysis of Rectangular Perforated Plates by COMSOL Multiphysics® Software

B. Raghavendra[1]
[1]SRM University & BITS Pilani University, Chennai, Tamil Nadu, India

Vibration analysis of perforated plates is extremely important when designing structures where resonance is the possible mode of failure. This paper deals with the vibration analysis of rectangular perforated plates with three different types of perforations. Vibration analysis is to be carried out by both COMSOL Multiphysics® Software and Experimental set-up. The applications of perforated ...

Numerical Modelling Of Sound Absorptive Properties Of Double-Porosity Granular Materials

R. Venegas, and O. Umnova
Acoustics Research Centre, University of Salford, Salford, United Kingdom

Granular materials have been conventionally used for acoustic treatment due to their sound absorptive and sound insulating characteristics. An emerging field is the study of acoustical properties of multi-scale porous materials. An example of these is a double-porosity granular material in which the grains are porous themselves. In this work, a computational methodology for modelling this type ...

Optimal Placement of Piezoelectric Plates to Control Multimode Vibrations of Rotating Beam

F. Botta[1], D. Dini[2], S. Gentili[1], G. Cerri[1]
[1]Dipartimento di Ingegneria Meccanica e Industriale, Università degli Studi di Roma Tre, Roma, Italy
[2]Department of Mechanical Engineering, Imperial College London, London, United Kingdom

Turbomachines blades are forced by a load resulting from the interaction with the fluid. The consequent vibrations, and the associated fatigue phenomena, can give catastrophic failures and the reduction of the blades life. It could be increased if damping system are used. The piezoelectric materials has received considerable attention by many researcher for their potential application in the ...

A Study of Seismic Robot Actuation Using COMSOL Multiphysics

S.L. Firebaugh, E.A. Leckie, J.A. Piepmeier, and J.A. Burkhardt
United States Naval Academy, Annapolis, Maryland, USA

Microrobotics has promising applications in microsurgery and microassembly. A challenge in these systems is interfacing with the robot. This project explores crawling robots that are powered and controlled through a global mechanical vibration field. By controlling the frequencies present in the vibration field, the user can then steer the robot. The “robot” has a rectangular body with ...

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.