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.

Investigation of Stability of Current Transfer to Thermionic Cathodes

M. Benilov, and M. Faria
Departamento de Física, Universidade da Madeira, Funchal, Portugal

Current transfer from high-pressure arc plasmas to thermionic cathodes may occur in a diffuse mode, when the current is distributed over the front surface of the cathode, or in a spot mode, when most of the current is localized in one or more small areas. Spectra of perturbations of 3D steady-state current transfer to thermionic cathodes of a high-pressure argon arc have been computed in the ...

FEM Simulation of the Scanning Electrochemical Potential Microscopy (SECPM)

R. Hamou, P. Biedermann, M. Rohwerder, and A. Blumeneau
Max-Planck-Institut für Eisenforschung GmbH, Düsseldorf, Germany

The present work focuses on modeling a new experimental technique: Scanning Electro-chemical Potential Microscopy (SECPM), which is used to probe the potential profile of the electric double layer (EDL). We used an electrostatic approach to compute the EDL potential measured within the metallic probe. Also, we investigated the effect of the interaction of the electrode/probe double layers on the ...

Electric Field Distributions and Energy Transfer in Waveguide-Based Axial-Type Microwave Plasma Source

H. Nowakowska[1], M. Jasínski[1], and J. Mizeraczyk[1,2]
[1]The Szewalski Institute of Fluid-Flow Machinery, Polish Academy of Sciences, Gdansk, Poland
[2]Dept. of Marine Electronics, Gdynia Maritime University, Gdynia, Poland

In this paper, we examine changes of the electric field distributions in waveguide-based axial-type microwave plasma source (MPS) during tuning procedure. The distributions strongly depend on position of the movable short, so does the wave reflection coefficient of the incident wave. A method of determining tuning characteristics of the MPS consisting in treating the MPS as a two-port network, ...

Modeling and Characterization of Superconducting MEMS for Microwave Applications in Radioastronomy

N. Al Cheikh[1], P. Xavier[1], J. Duchamp[1], and K. Schuster[2]
[1]Institute of Microelectronics, Electromagnetism and Photonics (IMEP-LAHC), Grenoble, France
[2]Institute of Millimetrics Radio Astronomy (IRAM), Grenoble, France

Superconducting GHz electronics circuits are frequently used in Radio Astronomy instrumentation. The features of these instrumentations can be significantly improved by using tuneable capacitances, which can be realized by electrically actuated, micromechanical bridges (MEMS) made of superconducting Niobium (Nb). In order to analyze the electromechanical behavior of such devices and the ...

High Vacuum Gas Pumping and Boundary Coupling

M. Cavenago
INFN/LNL, Laboratori Nazionali di Legnaro, Legnaro, Italy

Many scientific instruments are based on high vacuum equipment with a gas pressure maintained in the order of 1 Pa or below. The gas flow in the low pressure limit, called the molecular flow regime, is a case of transport with zero viscosity. The ability to solve an integral equation on the boundary with finite elements methods allows us to find the gas densities and flows in the ...

Three-Dimensional Simulation of Signal Generation in Wide-Bandgap Semiconductor Radiation Detectors

J. E. Toney[1]
[1]Pennsylvania State University Electro-Optics Center, Freeport, Pennsylvania, USA

We demonstrate the use of Comsol Multiphysics with Matlab to model signal generation in wide-bandgap semiconductor radiation detectors. A quasi-hemispherical detector design is compared with a simple, planar detector. Results show that the quasi-hemispherical design can simply and effectively compensate for the poor hole transport of most compound semiconductor materials.

Hyperbolic Heat Transfer Equation for Radiofrequency Heating: Comparison between Analytical and COMSOL Solutions

V. Romero-García[1], M. Trujillo[2], M.J. Rivera[2], J.A. López Molina[2], and E.J. Berjano[3]
[1]Centro de Tecnologías Físicas Acústica, Universidad Politécnica de Valencia, Valencia, Spain
[2]Dpto. Matemática Aplicada, Instituto Universitario de Matemática Pura y Aplicada, Universidad Politécnica de Valencia, Valencia, Spain
[3]Institute for Research and Innovation on Bioengineering, Universidad Politécnica de Valencia, Valencia, Spain

The Radiofrequency Heating (RFH) is widely employed to heat biological tissue in different surgical procedures. Most models analyze the RFH employing a Parabolic Heat Transfer Equation (PHTE) based on Fourier's theory. The PHTE can be used for problems involving long heating times or low thermal gradients. However, when the problem involves short heating times or extreme thermal gradients it is ...

Drying In Porous Media: Equilibrium And Non-Equilibrium Approaches For Composting Processes

A. Pujol[2], S. Pommier[3], G. Debenest[2], M. Quintard[2], and D. Chenu[1]
[1]Veolia Environnement, Limay, France
[2]IMFT, Toulouse, France
[3]INSA Toulouse, Toulouse, France

To understand origins and consequences of drying phenomenon during composting, a compositional drying model of a partially water-saturated porous media coupled with biodegradation has been developed. The different simulations carried out under COMSOL Multiphysics demonstrate the ability of the model to well describe the compositional drying of a partial water-saturated porous media and point out ...

Long Term Performance Of Borehole Heat Exchanger Fields With Groundwater Movement

S. Lazzari, A. Priarone, and E. Zanchini
DIENCA, University of Bologna, Bologna, Italy

A numerical investigation of the long-term performance of double U-tube borehole heat exchanger (BHE) fields, in the case of non-negligible effects of groundwater movement, is performed by means of COMSOL Multiphysics. Two time periodic heat loads, with a period of one year, are studied: Q1, with a partial compensation between winter heating (principal load) and summer cooling; Q2, with no ...

Numerical Simulation of a Building Envelope with High Performance Materials

M.H. Baghban[1], P. Jostein Hovde[1], and A. Gustavsen[2]
[1]Civil and Transport Engineering Department, Norwegian University of Science and Technology, Trondheim, Norway
[2]Department of Architectural Design, History and Technology, Norwegian University of Science and Technology, Trondheim, Norway

Simulation tools for building physics problems play an important role in design and understanding the behavior of energy efficient buildings. There are different tools available for simulation of these problems, but each simulation tool has its own advantages and limitations. In this paper, a heat transfer problem in an exterior building wall with high performance materials has been simulated in ...