Presentazioni e Articoli Tecnici

In questa sezione troverete i lavori presentati alle Conferenze mondiali COMSOL. Le presentazioni descrivono ricerche e prodotti innovativi progettati con COMSOL Multiphysics da colleghi di tutto il mondo. I temi delle ricerche presentate abbracciano un'ampia gamma di settori produttivi e aree applicative, in ambito elettrico, meccanico, fluidodinamico e chimico. Lo strumento di Ricerca Rapida vi permetterà di trovare le presentazioni che si riferiscono all'area di vostro interesse.

Time Domain Analysis of Large-Signal Circuit-Based Fully Distributed Model for High-Frequency, Multiple-Finger FETs

M. Waliullah1, S. Goodnick2, S. M. El-Ghazaly3, A. Cidronali4, and C. Toccafondi4
1Intel Corporation, Folsom, CA, USA
2Department of Electrical Engineering, Arizona State University, Tempe, AZ, USA
3Department of Electrical Engineering, University of Tennessee, Knoxville, TN, USA
4Department of Electronics and Telecommunication Engineering, University of Florence, Italy

A general fully-distributed equivalent circuit model for high frequency multiple finger power FETs is presented.In the multiple finger equivalent circuit model, the effects of electromagnetic (EM) wave propagation along the width of each finger and gate feeding line are modeled by distributed transmission line parameters. The generalized multiple finger large signal model is solved in the time ...

Modeling Ion Motion in a Miniaturized Ion Mobility Spectrometer

S. Barth, and S. Zimmermann
Drägerwerk AG & Co. KGaA, Lübeck, Germany

Ion mobility spectrometry provides fast detection of very low concentrations of chemical substances. Simple instrumentation combined with high sensitivity and high selectivity are the advantages of this technique. One well established field of application is the detection of hazardous compounds in air, such as chemical warfare agents, explosives and pollutants. A numerical model based on finite ...

Modelling of a Differential Sensor in Eddy Current Non-destructive Evaluation

A. Rosell[1], and G. Persson[2]
[1]Volvo Aero Corporation, Trollhättan, Sweden
[2]Chalmers University of Technology, Göteborg, Sweden

Interaction between the probe and a defect in eddy current non-destructive evaluation is studied. Evaluation of sensor signal response is the basis for the calculation. In this work a differential sensor is considered and the problem regarded here is problem 8 from the testing of electromagnetic analysis methods (TEAM) workshops. The truncation, referring to the position of the outer ...

Simulation and Analysis of a Borehole Transient Electromagnetic Reservoir Monitoring System

S.M. Dutta[1], A. Reiderman[1]
[1]Baker Hughes, Houston, TX, USA

Waterflooding and steam-flooding are used worldwide for EOR. Recently, CO2-flooding has attracted global attention as a means of EOR as well as for carbon capture and sequestration. These processes cause significant changes over time in the fluid composition of oil reservoirs. This paper demonstrates the feasibility of a borehole transient electromagnetic (TEM) system that can map the fluid ...

Prototype Probe Development for Liquid Injection Shutdown System Tube Gap Detection by Remote Field Pulsed Eddy Current Technique

T. V. Shyam[1], B. S. V. G. Sharma[1], J. N. Kayal[1]
[1]Bhabha Atomic Research Centre, Trombay, Mumbai, India

Pressurised Heavy Water Reactors (PHWR) play a prominent role in contributing power for the Nuclear Energy Programme in India. In 540MWe type PHWR reactors, there are horizontally placed Liquid Injection Shutdown System (LISS) tubes for injecting poison into the moderator to clamp down the nuclear power under trip conditions. The Horizontally placed LISS pipes are placed perpendicular to the ...

Three-Dimensional Numerical Study of the Flow Past a Magnetic Obstacle

M. Rivero[1], O. Andreev[2], A. Thess[3], S. Cuevas[4], T. Fröhlich[1]
[1]Institute of Process Measurement and Sensor Technology, Ilmenau University of Technology, Ilmenau, Germany
[2]Helmholtz-Zentrum Dresden-Rossendorf e. V., Institut für Sicherheitsforschung Abteilung Magnetohydrodynamik, Dresden, Germany
[3]Institute of Thermodynamics and Fluid Mechanics, Ilmenau University of Technology, Ilmenau, Germany
[4]Instituto de Energías Renovables, Universidad Nacional Autónoma de México, Temixco, Morelos, México

Flows of electrically conducting liquids in external magnetic fields are present in several applications. In this kind of flow, the inhomogeneous magnetic field creates a breaking force on the conducting fluid. As a result, a stagnant zone is formed in the zone affected by the localized field so that the fluid flows around it. Wakes in magnetohydrodynamic flows present interesting challenges ...

Investigation on an Encircling Pulsed Eddy Current Probe Performance Using COMSOL Multiphysics®

S. Majidnia[1], R. Nilavalan[1], J. Rudlin[2]
[1]Brunel University, London, United Kingdom
[2]TWI ltd, Cambridge, United Kingdom

Conventional eddy current techniques have been used to a great extent for detection of surface breaking defects in conductive materials. However, detection of sub-surface defects is limited due to the single frequency and skin effect phenomena. Pulsed Eddy Current (PEC) techniques overcome these limitations. This work involves modelling of an encircling coil around a steel pipe with and without ...

Tri-Axial Square Helmholtz Coils System to Generate Uniform Magnetic Field Volume - new

A. F. Restrepo[1], E. Franco[1], C. R. Pinedo[1]
[1]Universidad del Valle, Cali, Valle del Cauca, Colombia

The study of the effects of magnetic field stimulation in biological systems require devices capable of generating homogenous magnetic fields and further guarantee a controlled and repeatable exposure to different samples involved in the experiment [1]. This work presents analysis and validation of a tri-axial Square Helmholtz Coils (SHC) system, commonly used to generate highly uniform magnetic ...

Simple Finite Element Model of the Topografiner - new

H. Cabrera[1], D. A. Zanin[1], L. G. De Pietro[1], A. Vindigni[1], U. Ramsperger[1], D. Pescia[1]
[1]Laboratory for Solid State Physics, ETH Zürich, Zürich, Switzerland

In our recent experiments we are revisiting the topografiner technology for the imaging of surface topography with a resolution of a few nanometers. In these new technique called Near-Field Emission Scanning Electron Microscopy (NFESEM), low-energy electrons are emitted from a polycrystalline tungsten tip via electric-field assisted tunneling. In order to characterize and improve the capabilities ...

Traveling Plasma Wave Levitation of Objects Supported by Coanda Effect - new

R. Eisenschmid[1]
[1]OPTIMA pharma GmbH, Schwäbisch Hall, Germany

Electrostatically excited plasma waves can induce a “plasma wind” in the surrounding media or air. The lifted object has a shape of a flying saucer, just for better illustration. A travelling plasma wave propulsion requires a pre-ionized media around the surface and a travelling electrostatic field. A simplified plasma model was used to set up an EFD (electro fluid dynamic) approach into a ...

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