Ici vous trouverez les présentations issues des Conférences COMSOL à travers le monde. Réalisées par des utilisateurs de COMSOL Multiphysics, ces présentations explorent tous les domaines actuels d'innovation. Les applications couvrent pratiquement tous les secteurs industriels et impliquent des phénomènes électriques, mécaniques, fluidiques et chimiques. Utilisez la recherche rapide pour trouver les présentations les plus intéressantes dans votre domaine d'intérêt.

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 ...

Time-Domain Model of the Inner Ear to Study Nonlinear Responses

K. Gladine [1], J. Soons [1], J. Dirckx [1]
[1] University of Antwerp, Belgium

The ear doesn’t solely listen but it also speaks. Sounds formed in the inner ear which are measurable in the outer ear are called Otoacoustic emissions (OAEs). Some claim these are produced by the outer hair cells (OHCs), the amplifiers in the inner ear. Our hypothesis is that the OHCs only amplify distortion products (DPs) but do not produce them.

Stress Analysis on All-Ceramic Specimens of Different Geometries During Thermalcycling Tests

D. Fabris [1], B. Henriques [2], J. C. M. Souza [1], J. Guimarães [1], M. Fredel [1]
[1] Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
[2] Universidade Federal de Santa Catarina, Blumenau, SC, Brazil; and CMEMS-Uminho, Universidade do Minho, Guimarães, Portugal

Dental restorations can be made by different materials bonded together, which grant good mechanical resistance and aesthetic at the same time. In order to evaluate the behavior of dental restorations in the oral environment, a test, called thermocycler, is used, which simulates the temperature changes and the chemical environment of the mouth. The objective of this work is to evaluate thermal ...

Finite Element Evaluation of the Strength of Silicide-Based Thermoelectric Modules

A. Miozzo [1], S. Boldrini [1], A. Ferrario [1], M. Fabrizio [1],
[1] Institute of Condensed Matter Chemistry and Techologies for Energy - National Research Council of Italy, Padova, Italy

Silicide-based thermoelectric modules (TEMs) for power generation operate at mid-high temperature range. In the operating conditions, thermal stresses in materials with different coefficient of thermal expansion may reduce the mechanical strength of the modules. In this work, a finite element evaluation of the mechanical strength of a 16 legs thermoelectric module prototype operating with 300 K ...

Modeling of a Direct Methanol Fuel Cell

J. Drillet [1],
[1] DECHEMA-Forschungsinstitut, Frankfurt, Germany

This work aims at the modelling of a 5 cm^2 Direct Methanol Fuel Cell (DMFC) with mixed serial/parallel serpentine flow fields in terms of current/voltage behavior. One of the main challenge to overcome consists on lowering the so-called methanol cross over from the anode through the polymer membrane to the cathode that is responsible for mixed-potential formation at the cathode where both ...

3D Simulation of the Electric Field of Polymeric Insulators under Adverse Conditions

D. F. Reis [1], E. J. da Silva [1], I. J. S. Lopes [1],
[1] Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil

Recent studies report problems related to premature aging and degradation of high-voltage polymeric insulators. Corona activity, which is induced in areas of high electric field levels, is considered one of the leading causes of these problems. The insulator operation under adverse conditions including rain, fog, dew and pollution is affected by these key factors that modify the electric field ...

Pulsed Electric Field Based Material Removal in Microelectrical Discharge Machining

T. Roy[1],, P. Ranjan[2], , R. Balasubramaniam[2]
[1]Homi Bhabha National Institute, Mumbai, India
[2]Bhabha Atomic Research Centre, Mumbai, India

Micro electrical discharge machining (MEDM), a scaled down version of EDM process, is a micro machining process used to fabricate micro holes and intricate shapes in electrically conductive materials irrespective of its hardness. In this process, an electric spark is generated in the gap between the two electrodes (tool as cathode and workpiece as anode) submerged in dielectric that leads to a ...

Modeling Internal Erosion Processes in Soil Pipes

J. L. Nieber [1], G. V. Wilson [2], G. A. Fox [3],
[1] University of Minnesota, St. Paul, MN, USA
[2] United States Department of Agriculture - Agricultural Research Service National Sedimentation Laboratory, Oxford, MS, USA
[3] North Carolina State University, Raleigh, NC, USA

The erosion of the interior of soil pipes is an important process in the fields of geomechanics and geomorphology. Soil pipes can form in water holding structures like dams and levees, and water flow through these structures becomes concentrated into the soil pipes as they evolve by the process of internal erosion. With time the erosion process will lead to a soil pipe spanning the entire ...

直流 GIL 内金属微粒对表面电荷积聚影响的 COMSOL 三维仿真研究

倪潇茹 [1], 常帅 [1], 王志远 [1], 王靖瑞 [1], 于万水 [1],
[1] 华北电力大学

以 SF6 或 SF6/N2 混合气体为绝缘介质的 GIL 具有大容量、高可靠性和环境友好等特点,而 GIL 中存在的金属微粒污染问题是提高设备绝缘强度研究中的关键技术难题。在 GIL 中,金属微粒引起的电场畸变会带来一系列绝缘问题,这些问题需要进行深入研究。针对直流 GIL 中金属微粒污染问题,本文研究其对绝缘子表面电荷积聚的影响。充分考虑附着导电微粒的情况,建立了可以灵活设置微粒与绝缘子相对位置的三维模型,利用 COMSOL Multiphysics® 软件的 AC/DC 模块对三维空间中绝缘子下绝缘子形状及表面附着微粒的不同粘附形态对表面电荷积聚的影响进行了求解分析。基于麦克斯韦方程组理论,我们首先对绝缘子表面电荷的积聚情况进行分析。然后纳入微粒污染以及气体侧微观尺度空间离子的产生、复合、迁移和扩散等作用,进一步建立了微粒污染情况下包含气体侧微观机制的绝缘子表面电荷积聚模型。 ...

A Numerical Study for Rubber Particles Collection Involved in New Thermoforming Composite Process Using COMSOL Multiphysics®

R. Carbone[1], V. Antonelli[2][3], A. Langella[1], and R. Marissen[3]

[1]Material and Production Engineering Department, Università degli Studi di Napoli Federico II, Napoli, Italy
[2]Institute of Lightweight Structures, Technische Universität München, München, Germany
[3]Design and Production of Composite Structure, Delft University of Technology, Delft, The Netherlands

This paper deal of the forming process applied to the thermoplastic composites. A new thermoforming process that uses rubber particles collection as flexible mould was presented and numerically modeled. A characterization of the rubber in particles form was previously performed to value the material parameters in the user-defined hyperelastic constitutive laws employed in the FEM (Finite Element ...