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.

3D Electromagnetic Field Simulation in Microwave Ovens: A Tool to Control Thermal Runaway

T. Santos[1], L.C. Costa[1,2], M. Valente[1,2], J. Monteiro[1,2], and J. Sousa[3]
[1]University of Aveiro, Portugal
[2]I3N, Aveiro, Portugal
[3]TEKA Portugal S.A., Ílhavo, Portugal

In microwave heating applications, the energy is introduced directly into the volume of the material and as consequence the quality of the process is highly dependent on the uniformity of the electromagnetic field distribution along it. That is, the non uniformity of the heating is a potential problem with serious consequences. Thermal runaway is the most critical, in materials with temperature ...

Finite-element Analysis of Properties in Real and Idealized Photonic Crystal Fibres, Application to Supercontinuum Generation

Gérôme, F., Viale, P., Tombelaine, V., Leproux, P., Auguste, J.L., Février, S., Blondy, J.M., Couderc, V.
IRCOM, CNRS UMR 6615, Limoges, France

Using a full-vector finite-element method, we calculate modal properties in index-guiding photonic crystal fibres. The influence of the deformation of the geometry in actual fibre structures is evaluated and compared to the idealized-model. These results are applied to the supercontinuum generation. Moreover, development of MATLAB softwares for FEMLAB 3.1 are presented.

Numerical Study of Local Density of States in Photonic Crystal Waveguides

A. Javadi[1], P. Lodahl[1]
[1]Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark

In this contribution we study how a planar photonic crystal waveguide (PhCW), created by introducing a line defect in the photonic crystal, can modify the projected local density of states (LDOS) for a dipole emitter. We use the COMSOL Multiphysics® RF Module to carry out eigenvalue calculations studies on PhCW. When the dipole is in resonance with the waveguide mode, the enhancement Fp of ...

Scan Angle Stability of a Second-Order Plasma-Switched Frequency Selective Surface

L. W. Cross[1], M. J. Almalkawi[2]
[1]Imaging Systems Technology, Toledo, OH, USA
[2]EECS Department, College of Engineering, University of Toledo, Toledo, OH, USA

Large-area, light-weight electromagnetic protection (EP) structures are needed to protect sensitive microwave sensors and communications systems from high-power microwave (HPM) and electromagnetic pulse (EMP) threats. This paper presents the use of COMSOL Multiphysics® for electromagnetic simulation of a plasma-based frequency selective surface (FSS) structure that can provide significant ...

Universal Dielectric Response of Atmospheric Ice Using COMSOL Multiphysics®

U.N. Mughal[1], M.S. Virk[1], K. Zaman[1]
[1]Narvik University College, Narvik, Norway

Heterogeneous materials with different phases, are conductive and insulating (dielectric), and are physically present in different natural materials as e.g. atmospheric ice. Jonscher’s proposed ‘universal dielectric response’ is not sufficient for such materials, as it only reflects conductivity as a nonlinear function of frequency, whereas at lower temperatures dipolar vibrations are also ...

Self-Consistent Modeling of Thin Conducting Wires and Their Interaction with the Surrounding Electromagnetic Field

G. Eriksson[1]
[1]ABB AB, Corporate Research, Västerås, Sweden

It is demonstrated how the RF Module of COMSOL Multiphysics® can be used to approximately model thin conducting wires or cables and how they interact with a surrounding electromagnetic field. Despite being non-stringent the method can reasonably well predict currents induced by an applied electromagnetic field in wires, and networks of wires, as well as fields radiated from current-carrying ...

Calculating the Capacitance of Shielded Microstrip Lines

S. M. Musa, and M. N. O. Sadiku
College of Engineering, Prairie View A&M University, Prairie View, TX, USA

This paper presents a numerical analysis for calculating the capacitance of singlestrip and double-strip shielded transmission lines. Modeling and simulation of the capacitance of shielded microstrip lines using COMSOL are illustrated. We determined the capacitance per unit length of each shielded microstrip line.We compared our results with those obtained by other methods and found them to be in ...

Modeling Electrical and Thermal Conductivities of Biological Tissue in Radiofrequency Ablation

M. Trujillo[1], E. Berjano[1]
[1]Universidad Politécnica de Valencia, Valencia, Spain

Radiofrequency ablation is a minimally invasive techinique which is used to treat some kinds of cancer. The realism of theoretical models is very important. An influential factor in this realism is mathematical functions that model the temperature-dependence of tissue thermal and electrical conductivities. The aim of this work is to review the mathematical functions employed to model the ...

Three-Dimensional (3D) Modeling of Heat and Mass Transfer during Microwave Drying of Potatoes

H. Zhu[1][2], T. Gulati[2], A. K. Datta[2], K. Huang[1]
[1]Institute of Applied Electromagnetics, Sichuan University, Chengdu, China
[2]Department of Biological and Environment Engineering, Cornell University, Ithaca, NY, USA

Microwave drying of fruits and vegetables in a domestic oven has been found to result in large textural changes in the product such as puffing, crack formation and even burning due to the inhomogeneous heating of the microwaves. Microwave drying of potatoes is a complex interplay of mass, momentum and energy transport. Three phases are considered in the system: solid (skeleton), liquid (water) ...

Plasmonic Properties of Bimetal Nanoshell Cylinders and Spheres

K. Ehrhold[1], S. Christiansen[1,2], and U. Gösele[1]
[1]Max Planck Institute of Microstructure Physics, Halle, Germany,
[2]Institute of Photonic Technology, Jena, Germany

Plasmonics is a new branch of the fascinating field of photonics and develops concepts to quench light beyond the diffraction limit and enhance electromagnetic fields. These enhancements occur in metals as localized surface plasmon polaritons (LSP) a coupling of the surface density oscillations of the electron gas to the incident light. With threedimensional nano-structures of coinage metals that ...

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