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.

Cascades of Secondary Particles in High Voltage Accelerators

M. Cavenago[1], P. Antonini[1][3], P. Veltri[2], N. Pilan[2], V. Antoni[2], and G. Serianni[2]
[1]INFN-LNL, Legnaro, Padova, Italy
[2]Consorzio RFX, Padova, Italy
[3]Centro Ric. E. Fermi, Roma, Italy

A very simplified system for high voltage test is studied, considering reason for voltage holding failures which are not covered by conventional and local design criteria. A first understanding of the problem is obtained by solving the electrostatic potential in a 2D axis symmetric geometry, considering in detail the electrode shapes, and following a cascade of particle between opposite ...

Numerical Validation of the Efficiency of Dual-Frequency Radiofrequency Ablation

A. Candeo[1] and F. Dughiero[1]
[1]Department Electrical Engineering, University of Padova, Padova, Italy

Radiofrequency Ablation (RFA) represents a valid alternative for treating liver metastases in medically complicated patients. Conventional devices currently operate at 500 kHz, due to good conducting properties of tissues. However, the use of lower frequencies (i.e. 20 kHz) has been recently reported to enhance the treatment effectiveness, due to a more pronounced difference in electrical ...

Numerical Study of an LTD Stirling Engine with Porous Regenerator

N. Martaj[1], P. Rochelle[1][2], L. Grosu[1], R. Bennacer[3], and S. Savarese[4]
[1]Universitè de Paris, Paris, France
[2]Institut Jean Le Rond d'Alembert, Université Paris 6
[3]Laboratoire LEEVAM «Environnement, Energétique, Valorisation, Matériaux», Universitéde Cergy-Pontoise
[4]COMSOL France, 5 pl. R Schuman, 38000 Grenoble

The alternative engines of Stirling type, are engines running on "hot air", using both an external heat source and regeneration. They should be considered as an alternative for the effective conversion of renewable energy sources into work, with their theoretical yield equal to the theoretical Carnot limit. The output efficiency and the power of these engines are strongly related to the ...

An All-Purpose Full-Vectorial Finite Element Model for Arbitrarily Shaped Crossed-Gratings

G. Demésy[1], F. Zolla[1], A. Nicolet[1], and M. Commandré[1]
[1]Institut Fresnel, Université Aix-Marseille III, École Centrale de Marseille, France

We demonstrate the accuracy of the Finite Element Method (FEM) to characterize an arbitrarily shaped crossed-grating in a multilayered stack illuminated by an arbitrarily polarized plane wave under oblique incidence. To our knowledge, this is the first time that 3D diffraction efficiencies are calculated using the FEM. The method has been validated using classical cases found in the literature. ...

Simulation of a Heated Tool System for Jet Electrochemical Machining

M. Hackert[1], G. Meichsner[2], and A. Schubert[1][2]

[1]Chair Micromanufacturing Technology, Faculty of Mechanical Engineering, Chemnitz University of Technology, Chemnitz, Germany
[2]Fraunhofer Institute for Machine Tools and Forming Technology, Chemnitz, Germany

Jet Electrochemical Machining (Jet-ECM) is an unconventional procedure using localized anodic dissolution for micromachining. An increasing of the electrolyte temperature will lead to an increase of the electrical conductivity of the electrolyte by about 30% and to a reduction of the dynamic viscosity of the electrolyte by about 25 %. Both will improve the process. Therefore a Jet-ECM tool system ...

Growth and Remodelling of Intracranial Saccular Aneurysms

A. Di Carlo[1], V. Sansalone[2], A. Tatone[3], and V. Varano[1]
[1]Modelling and Simulation Lab, Università Roma Tre, Roma, Italy
[2]Laboratoire de Mécanique Physique, Université Paris Est, Paris, France
[3]DISAT, Università degli Studi dell’Aquila, L'Aquila, Italy

We present a mechanical model a growing spherical shell suitable for predicting the evolution of a Saccular Cerebral Artery Aneurysms (SCAA). It relies basically on the Kröner-Lee decomposition, used to describe the interplay between the current and the relaxed configuration of body elements. Rupture or stabilization of a SCAA are the end effect of a number of biological mechanisms, still poorly ...

An Extension of Lauwerier’s Solution for Heat Flow in Saturated Porous Media

S. Saeid[1] and F.B.J. Barends[2]
[1]Technical University of Delft, Delft, The Netherlands
[2]Deltares and TU-Delft, Delft, The Netherlands

One of the crucial topics in this century is sustainable energy. In this respect, the exploitation of geothermal energy from deep hot aquifers becomes opportune. Hence, insight is required in the heat balance of potential aquifer systems. Essential issues are convection, conduction and dispersion. This article focuses on Lauwerier’s problem. As an extension, it is suggested that beside ...

Thin Membrane Modelling for the Electrical Stimulation of Auditory Nerve

A. Grünbaum[1], S. Petersen[1], H.W. Pau[2], and U. van Rienen[1]

[1]IEF funded by DFG Research Training Group 1505/1 Welisa, University of Rostock, Rostock, Germany
[2]Otolaryngology “Otto Körner”, University of Rostock, Rostock, Germany

Modeling of 2-5 μm thin membranes into a cochlea with a width of 2 cm is computationally. The paper is focused on two approximative methods used to overcome this problem and in addition a simple model challenging of a plate capacitor with a thin membrane of different thickness in-between is presented. The results of simulations with both thin layer approximation methods are compared with those ...

Modeling Contaminant Diffusion in Highly Complex Rock Structures

N. Diaz[1], A. Jakob[1], L. Van Loon[1], and D. Grolimund[2]
[1]Paul Sherrer Institut NES/LES, Villigen PSI, Switzerland
[2]Paul Sherrer Institut NES/SLS, Villigen PSI, Switzerland

Opalinus clay is currently being proposed as a potential host rock for radioactive waste repository in deep geological formation. It is then important for performance assessments to understand the transport properties of such rocks. Clay materials are characterized by low hydraulic conductivities and diffusion is assumed to be the main transport mechanism. The studied rock is a complex assembly ...

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