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.

Numerical Evidence of Unrest-Related Electromagnetic Effects in the Campi Flegrei Caldera, Italy

G. Perillo [1], G. De Natale [2], M. G. Di Giuseppe [2], A. Troiano [2], C. Troise [2],
[1] University of Naples Parthenope, Naples, Italy
[2] INGV – Osservatorio Vesuviano, Naples, Italy

Electric, magnetic and electromagnetic (em) methods are widely used to monitor active volcanoes. A review of such applications is presented in Johnston (cit). Em signals were recorded in correspondence of numerous volcanic eruptions, for example in the case of the Mt. Unzen in Giapppone, of Merapi in Indonesia, Etna in Italy and during rapid deformation in Long Valley in California. ...

电容成像检测技术研究与分析

李振 [1], 毛冬麟 [1], 李晨 [1], 路鹏 [1],
[1] 中国石油大学(华东),青岛,中国

引言:电容成像检测技术是一种新型的无损检测技术,它是利用一对共面电极板之间产生的准静态边缘电场对缺陷进行检测,电容成像探头的形状是成像性能的关键因素,据此设计了点对点三角形探头(A型)、边对边三角形探头(B型)、正方形探头(C型)和圆形探头(D型),如图1所示,并利用 COMSOL Multiphysics® 对它们的性能进行分析。 计算方法:通过 COMSOL Multiphysics 软件的 AC/DC 模块对电容成像探头的电容值、电势分布和灵敏度进行研究。仿真中用到了“静电(es)”接口。 结果:仿真得到了四种电容成像探头的电容值(图2)、电势分布图(图3)和灵敏度分布图(图4)。 结论:电容成像探头的探测深度与灵敏度之间相互制约。在这四种电容成像探头中,点对点三角形探头的电容值是最大的,电势分布是趋于集中的,边对边三角形探头的灵敏度是最高的 ...

A 3D Thermal Model for Lunar Surface Using COMSOL Multiphysics® Software: Validation and Results

K. Durga Prasad [1], S.V.S. Murty [1], V. K. Rai [1],
[1] Planetary Sciences Division, Physical Research Laboratory, Ahmedabad, Gujarat, India

A comprehensive three dimensional finite element thermal model has been developed using COMSOL Multiphysics® software to understand the thermo-physical behaviour of the uppermost regolith layer of the moon. The model can simulate variable layers, layer thickness and dimensions and can account for complex geometry, different size, irregular meshing, parametric based variation in physics and ...

自电泳机理驱动的微纳米马达仿真模拟研究

王威 [1], 周超 [1],
[1] 哈尔滨工业大学深圳研究生院,深圳,中国

微纳米马达是一种能将周围环境的能量转化为自身自主运动的新型智能仿生材料,其在药物的运输与释放,低维材料的合成以及软物质研究中有着重要的应用[1]。基于自电泳的双金属棒马达是研究时间最长的一类马达,它有着与自然界中类似的自组装和群体行为的特性[2]。但是其运动机理复杂且涉及到多个物理场的紧密耦合,这就为其进一步的研究和应用带来了一定的困难。 COMSOL Multiphysics® 可以方便地进行多物理场的模拟。图(1)展示了双金属棒的自电泳机理, 由于棒两端的化学反应造成了带电离子浓度的分布不均匀,进而产生自生电场驱动马达运动。其中传质过程、流体流动以及电场形成相互影响,环环相扣[3]。基于以上物理过程,我们对 COMSOL 中稀物质传递,静电和蠕动流接口进行了有效的耦合,从而实现了马达周围离子场,电场和流场的模拟(图2),在此基础之上,我们研究了马达的运动速度(图3) ...

Transient Diffusion Modeling of Methane Plume and Source Localization

S. K. Nayaka[1],, S. Roya [1],, K. Ghosha [1],, S. Aroshb [2],, S. Prakashb[2],, S. P. Duttaguptaa [1][2]
[1] Center for Research in Nanotechnology and Science, IIT Bombay, Mumbai, Maharashtra, India.
[2] Dept. of Electrical Engineering, IIT Bombay, Mumbai, Maharashtra, India.

Methane detection and quantification is of great importance due to its natural abundance, potential to cause explosions and known greenhouse effect. Leak detection and concentration monitoring at source is highly challenging as CH4 is odorless and colorless. This can be performed mounting sensor network over a potential diffusion area. It requires optimal positioning of those sensor nodes to ...

Finite Element Modeling of Dielectric-Paraelectric Composite Materials

K. Zhou, S. Alpay, and S. Boggs
Institute of Material Science, University of Connecticut, Storrs, CT, USA

Finite Element analysis is used to model 2-D and 3-D paraelectric-dielectric composites (BaTiO3 spherical fillers randomly distributed in constant dielectric matrix). The effective dielectric response and tunability are studied under different filler sizes and different volume fractions. The results are consistent with previous theoretical and experimental results: with the increasing of filler ...

Modeling of the Transport Phenomena in Lithium-Ion Battery Electrolytes

A. Nyman, M. Behm, and G. Lindbergh
Applied Electrochemistry, School of Chemical Science and Engineering, Royal Institute of Technology Stockholm, Sweden

Modeling of mass transport is an important step in evaluating lithium-ion battery electrolytes and understanding cell performance. For high-power applications, concentration gradients in the electrolyte lead to limiting currents, which limit the power-density of the battery. The model has been used for determining a complete set of transport and thermodynamic properties for LiPF6 dissolved in an ...

Laminar Thermal Mixing in Coating Flows

A. Haas[1], M. Scholle[1], A. Aksel[1], H.M. Thompson[2], R.W. Hewson[2], and P.H. Gaskell[2]

[1]Department of Applied Mechanics and Fluid Dynamics, University of Bayreuth, Bayreuth, Germany
[2]School of Mechanical Engineering, University of Leeds, Leeds, United Kingdom

Heat transfer in a plane shear flow configuration consisting of two infinitely long parallel plates is considered. In laminar flows over undulated substrates eddies can be generated due to the kinematical constraints. A closed form analytical solution for the velocity field, based on lubrication theory as well as a semi-analytic solution for the temperature field is derived for the creeping ...

A Study of Laser Doppler Anemometer Using COMSOL Multiphysics®

I. Lancranjan[1] and C. Gavrila[2]
[1]Advanced Study Centre, National Institute for Aerospace Research “Elie Carafoli”, Bucharest, Romania
[2]Technical University of Civil Engineering Bucharest, Bucharest, Romania

Laser anemometers based on application of Doppler Effect have been developed and are used in-flight, on aircrafts for measurement of air flow parameters, mainly its speed versus the airplane. The air speed measurements are vital for safe flights. The main basic idea of Doppler techniques consists in measuring the frequency of scattered light. In this paper, we propose a study of a laser Doppler ...

Hydrogen Vehicle Leak Modelling in Indoor Ventilated Environments

A. Hallgarth[1], A. Zayer[1], A. Gatward[2], and J. Davies[2]
[1]Hazard Research & Risk Consultants Ltd, Aberystwyth, Wales, United Kingdom
[2]Independent Consultants, United Kingdom

This paper presents and discusses HazRes’ research and results associated with the simulation and modelling of hydrogen release and dispersion events in indoor enclosed environments, using COMSOL Multiphysics. HazRes has developed a gas dispersion model in COMSOL, which takes into account the effects of buoyancy, localized ventilation effects and turbulence generated by obstacles on the ...