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 ...
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, M. Jasínski, and J. Mizeraczyk[1,2]
The Szewalski Institute of Fluid-Flow Machinery, Polish Academy of Sciences, Gdansk, Poland
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, ...
N. Al Cheikh, P. Xavier, J. Duchamp, and K. Schuster
Institute of Microelectronics, Electromagnetism and Photonics (IMEP-LAHC), Grenoble, France
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 ...
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 ...
J. E. Toney
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, M. Trujillo, M.J. Rivera, J.A. López Molina, and E.J. Berjano
Centro de Tecnologías Físicas Acústica, Universidad Politécnica de Valencia, Valencia, Spain
Dpto. Matemática Aplicada, Instituto Universitario de Matemática Pura y Aplicada, Universidad Politécnica de Valencia, Valencia, Spain
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 ...
A. Pujol, S. Pommier, G. Debenest, M. Quintard, and D. Chenu
Veolia Environnement, Limay, France
IMFT, Toulouse, France
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 ...
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 ...
M.H. Baghban, P. Jostein Hovde, and A. Gustavsen
Civil and Transport Engineering Department, Norwegian University of Science and Technology, Trondheim, Norway
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 ...