Artigos Técnicos e Apresentações

Aqui você encontrará apresentações realizadas nas Conferências de Usuários COMSOL de todo o mundo. As apresentações englobam pesquisas e produtos inovadores feitas por engenheiros e cientistas usando o COMSOL Multiphysics. Os tópicos abramgem uma grande gama de indústrias e aplicações, como elétrica, mecânica, escoamento e química. Use a função de busca "Quick Search" para encontrar apresentações na sua área de interesse.

Wave Carpet Simulation using Coupled Hydro-elastic FEMLAB Model

Ibragimov A., Koola, P.M.
Texas Tech University, Mathematics and Statistics, Lubbock TX, BSI One KBSI Place, East University, TX

Wave Carpet is a novel deep offshore wave-power floating system concept funded by the Office of Naval Research that will have low overall life cycle cost due to an integrated design and be rapidly redeployable. In this paper we numerically model the Wave Carpet motion using a coupled hydro-elastic time-domain solution. The major feature of the mathematical model is the presence of non ...

Analysis of Sound Propagation in Lined Ducts by Means of a Finite Element Model

D. Borelli[1] and C. Schenone[1]
[1]DIPTEM, University of Genova, Genova, Italy

The present paper describes the results of a Finite Element Model used to analyze sound propagation in lined ducts. By means of a numerical model it was possible to predict the insertion loss inside rectangular lined ducts in a frequency range from 250 Hz to 4000 Hz. The model was validated by a comparison with experimental data obtained in accordance to ISO 11691 and ISO 7235 standards. 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.

On the Numerical Modeling of Elastic Resonant Acoustic Scatterers

V. Romero-García[1], A. Krynkin[2], J.V. Sánchez-Pérez[1], S. Castiñeira-Ibáñez[3], and L.M. Garcia-Raffi[4]
[1]Centro de Tecnologías Físicas Acústica, Universidad Politécnica de Valencia, Valencia, Spain
[2]School of Computing, Science & Engineering, University of Salford, Salford, United Kingdom
[3]Depto. Física Aplicada, Universidad Politécnica de Valencia, Valencia, Spain
[4]Instituto Universitario de Matemática Pura y Aplicada, Universidad Politécnica de Valencia, Valencia, Spain

The elastic and geometrical properties of Low Density Polyethylene (LDPE) foam are used in this paper to improve the attenuation properties of periodic arrangements of acoustic scatterers known as Sonic Crystals (SCs). A specific recycled profile of LDPE foam is used as elastic-acoustic scatterer. The acoustic spectrum of the single scatterer shows two attenuation peaks in the low frequency ...

Towards a Finite Element Calculation of Acoustical Amplitudes in HID Lamps

B. Baumann[1], M. Wolff[1], J. Hirsch[2], P. Antonis[2], S. Bhosle[3], and R. Valdivia Barrientos[4]
[1]Hamburg University of Applied Sciences, Hamburg, Germany
[2]Philips Lighting, Eindhoven, The Netherlands
[3]LAPLACE, Université de Toulouse and CNRS, Toulouse, France
[4]National Institute of Nuclear Research, Salazar, Ocoyoacac, Mexico

High intensity discharge lamps can experience flickering and even destruction, when operated at high frequency alternating current. The cause of these problems has been identified as acoustic resonances inside the lamp’s are tube. Here, a finite element approach for the calculation of the acoustic response function is described. The developed model does not include the plasma dynamics.

AlN/ZnO/Silicon Structure Combining Surface Acoustic Waves And Waveguiding Layer Acoustic Wave

O. Legrani[1], O. Elmazria[1], S. Zhgoon [2], L. Le Brizoual[3], and A. Bartasyte[1]
[1]Institut Jean Lamour, CNRS-Nancy University, Vandoeuvre lès Nancy, France
[2]Moscow Power Engineering Institute, Krasnokazarmennaja, Moscow, Russia
[3]Institut des Matériaux Jean Rouxel, Université Nantes, CNRS, Nantes, France

In this work, the theoretical study for the realization of waveguiding layer acoustic waves devices based on AlN/IDT/ZnO/Silicon structure using the modeling software COMSOL Multiphysics (2D) is presented. The effect of thicknesses of AlN and ZnO thin films on the evolution of frequency response, phase velocity and electromechanical coupling is studied. The adequate structure is determined for ...

Design of Traveling Wave Ultrasonic Vibration Disk for Nano-particles in Liquid Dispersion

J. Muraoka, and T. Suzuki
Yamagata Research Institute of Technology

The traveling wave ultrasonic vibration disks for dispersion of particles were designed by using of FEM analysis. The vibration disks are required specific vibration pattern, which contains three nodal lines. The vibration disk thickness was calculated to be matched the resonance frequency of bolted langevin type transducer and the specific vibration pattern. The alignment of the transducer was ...

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 ...

Effects Of The Microstructure Of Fibrous Media On Their Acoustic Properties

C. Peyrega, and D. Jeulin
Center of Mathematical Morphology, Mines ParisTech, Fontainebleau, France

This study is a part of the Silent Wall ANR project, to which the Center of Mathematical Morphology is associated. Its main objective is to build an acoustical and thermal insulating system for buildings, composed of fibrous materials. The material is composed of two phases: the fibrous network and the air surrounding it. At the microscopic scale the absorption of the acoustic wave is mainly due ...

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 ...

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