Here you will find presentations given at COMSOL Conferences around the globe. The presentations explore the innovative research and products designed by your peers using COMSOL Multiphysics. Research topics span a wide array of industries and application areas, including the electrical, mechanical, fluid, and chemical disciplines. Use the Quick Search to find presentations pertaining to your application area.

Virtual Prototype of a Dielectric Window for High-Power Microwave Tubes - new

A. Leggieri[1], D. Passi[1], F. di Paolo[1]
[1]Dipartimento di Ingegneria Elettronica, Università degli Studi di Roma Tor Vergata, Rome, Italy

This paper describes the Virtual Prototype of a Dielectric Window or High Power Microwave Vacuum Tubes and Linear Accelerators. Design formulas are provided and Computer Aided Design techniques based on COMSOL Multiphysics® software are proposed. The virtual prototype considers the Thermo-mechanical effects due to the joule effect induced by the power which crosses the DW and the Thermal contact ...

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 ...

Antenna and Plasmonic Properties of Scanning Probe Tips at Optical and Terahertz Regimes - new

A. Haidary[1], P. Grütter[1], Y. Miyahara[1]
[1]Physics Department, McGill University, Montreal, QC, Canada

A wide variety of near-field optical phenomena such as apertureless near-field scanning microscopy (ANSM) at optical and terahertz (THz) regimes and surface enhanced Raman scattering relies on the electric field enhancement at the end of a sharp tip. Achieving and controlling this electric field enhancement is a key challenge for a wide range of applications such as surface modification, data ...

Optical Forces and Torques Acting on Non-spherical Metallic Nanoparticles

M. Siler[1], O. Brzobohaty[1], V. Karasek[1], P. Zemanek[1]
[1]Inst. Scientific Instruments of the ASCR, Brno, Czech Republic

Metallic nanoparticles (NPs) are nowadays used in various areas of biology, chemistry or physics. Focused laser beams, optical tweezers, may be used to manipulate such NPs. However, experimental studies showed that there is a discrepancy between their predicted and observed behavior. Models assuming the spherical shape of a nanoparticle predict spatial confinement only for particles smaller than ...

Simulations of Negative Curvature Hollow-core Fiber - new

J. Zhang[1], Z. Wang[1], J. Chen[1]
[1]College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha, Hunan, China

COMSOL Multiphysics® software was used to simulate and analyze the transmission attenuation spectra of the negative curvature hollow-core fiber (NCHCF) over the wavelength from 2.7 μm to 4.2 μm. The effect of thickness of capillaries and the effect of the distance between the capillaries on confinement loss spectra were studied, which agreed well with the high-loss and low-loss bands predicted ...

Simulation of Vector Mode Grating Coupler Interfaces for Integrated Optics

C. T. Nadovich [1],
[1] Lafayette College, Easton, PA, USA

The use of grating couplers to couple conventionally phased and polarized light near vertically in and out of optical slab or film waveguides [1] represents an attractive method to interface optical fiber to photonic ICs. Previously developed grating coupler designs use transversely uniform grating structures matched to conventional scalar fiber modes. The performance of these geometries can be ...

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 ...

Coupled RF Thermal Analysis of High Power Couplers for Accelerator Cavities

R. Kumar[1], P. Singh[1]
[1]Bhabha Atomic Research Center, Trombay, Mumbai, India

High-power couplers working at 350 MHz for particle accelerator cavities are presently under development in the LEHIPA project at BARC. It is important to analyze RF losses on conducting surfaces and resulting thermal profiles. COMSOL Multiphysics® is used to study these coupled RF-thermal effects and estimate cooling requirements for these couplers. The RF loss on the copper conductors and ...

Dispersion Analysis in Coaxial Cables at High Frequencies

S. C. Hegde[1]
[1]VIT University, Vellore, Tamil Nadu, India

The coaxial cable is one of the most commonly used bandwidth limited signal transmission line.Dispersion is a signal distortion phenomenon which arises due to frequency dependence of phase velocity of signal components. This phenomenon was explained through time domain approach by studying time taken by signals of various frequencies to propagate through the cable, which eventually may cause ...

Development of a 10 kW Microwave Applicator for Thermal Cracking of Lignite Briquettes

B. Lepers [1], G. Link [1], J. Jelonnek [1]
[1] Karlsruhe Institute of Technology, Institute for Pulsed Power and Microwave Technology, Karlsruhe, Germany

Introduction: The use of microwave energy for thermal cracking (from thermal stress and water pore pressure) of lignite-coal briquettes increases the lignite friability [1] and is beneficial for later chemical treatment inside a gasifier (for methanol production for example). An adequate use of microwave energy can improve the overall efficiency of the gasification process based on lignite ...