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. Paoli, L. Seminara, D.D. Caviglia, A. Garibbo, and M. Valle
Department of Biophysical and Electronic Engineering, University of Genova, Genova, Italy
SELEX Communications S.p.A., Genova, Italy
Gas sensor arrays based on metal oxides operating at high temperature are commonly used in many application fields. They can operate on different principles and each sensor may show very different responses to the individual gases in the environment. Data coming from the array can be merged for reliable gas detection. One point which is common to the different sensors types is that the ...
A. Gizzi, C. Cherubini, S. Migliori, and S. Filippi
Nonlinear Physics and Mathematical Modeling Lab, Engineering Faculty, University Campus Bio-Medico, Roma, Italy
International Center for Relativistic Astrophysics, University of Rome La Sapienza, Roma, Italy
Alberto Sordi Foundation, Research Institute on Aging, Roma, Italy
Postoperative or paralytic Ileus (PI) is a temporary aftermath of major abdominal surgeries. PI prevents the passage of food throughout the lumen leading to bloating, distension, emesis and pain. A plausible mathematical model for this phenomenology physiologically fine tuned including thermal variations, is presented here. Using COMSOL Multiphysics the existing intestinal ionic model have been ...
VTT, Technical Research Centre of Finland, Espoo, Finland
Radionuclide transport modeling is a part of the research concerning geological disposal of spent nuclear fuel. Typically, the transport models near a single deposition hole focus on the reactions of nuclides, while the model geometry and the flow of groundwater are often simplified. In this paper, instead, a radionuclide transport model in a detailed 3D geometry with no reactions is introduced. ...
Screening Effects in Probing the Electric Double Layer by Scanning Electrochemical Potential Microscopy
R.F. Hamou, P.U. Biedermann, A. Erbe, and M. Rohwerder
Max-Planck-Institut für Eisenforschung GmbH, Düsseldorf, Germany
A computational method is developed to study probing the electric double layer by Scanning Electrochemical Potential Microscopy. The model is based on a modified Poisson- Boltzmann equation, which takes into account steric effects. We investigated the effect of metallic apex protrusion and the Open Circuit Potential (OCP) of the tip on the probed potential. A clear electrostatic screening effect ...
Variation of the Frost Boundary below Road and Railway Embankments in Permafrost Regions in Response to Solar Irradiation and Winds
N.I. Kömle and W. Feng
Space Research Institute, Austrian Academy of Sciences, Graz, Austria
State Key Laboratory of Frozen Soil Engineering, Cold and Arid Regions Environmental and Engineering Research Institute, Lanzhou, China
We present COMSOL solutions for a coupled gas flow and heat transfer problem, which occurs particularly when traffic pathways are constructed in high altitude and arctic regions, where the underground is frozen soil. To avoid melting of the frozen ground (which usually leads to mechanical instability) one has to find suitable measures to keep the subsurface soil and the embankment suitably cool. ...
B. Bozzini, S. Maci, I. Sgura, R. Lo Presti, and E. Simonetti
Dipartimento di Ingegneria dell’Innovazione, Università del Salento, Lecce, Italy
Dipartimento di Matematica, Università del Salento, Lecce, Italy
ENEA Casaccia, Dipartimento TER, Centro Ricerche Casaccia, S. Maria di Galeria, Roma, Italy
This paper describes the numerical modeling of a key material-stability issue within the realm of Molten Carbonate Fuel Cells (MCFC). The model describes the morphological and attending electrocatalytic evolution of porous NiO electrodes and is apt to predict electrochemical observables that can be recorded during Fuel Cell operation. The model has been validated with original experimental data ...
Simulating the Influence of the Nozzle Diameter on the Shape of Micro Geometries Generated with Jet Electrochemical Machining
A. Schubert, M. Hackert, and G. Meichsner
Chair Micromanufacturing Technology, Faculty of Mechanical Engineering, Chemnitz University of Technology, Chemnitz, Germany
Fraunhofer Institute for Machine Tools and Forming Technology, Chemnitz, Germany
Jet Electrochemical Machining (Jet-ECM) is an unconventional procedure for micromachining. Based on localized anodic dissolution three-dimensional geometries and microstructured surfaces can be manufactured using Jet-ECM. COMSOL Multiphysics is used at Chemnitz UT to simulate the electric current density in the jet and the dissolution process. A mesh displacement dependent on the normal current ...
P. Schmitz, A. Cockx, S. Geoffroy, and J. Gunther
Biochemical Engineering Dpt., Université de Toulouse, Toulouse, France
Chemical Engineering Dpt., Université de Toulouse, Toulouse, France
Mechanical Engineering Dpt., Université de Toulouse, Toulouse, France
An undergraduate course is developed to initiate future engineers to multiphysics numerical simulation by approaching concrete cases in various fields such as: heat transfers, fluid flow, mechanics, chemistry and electrostatics. The so called “Virtual Experiments” course consists of four projects given successively to students. Each project lasts about ten hours. The major notions related to ...
G. Petrone, L. Cammarata, and G. Cammarata
Department of Industrial and Mechanical Engineering, University of Catania, Catania, Italy
Ventilation and Indoor Air Quality (IAQ) are issues of very high interest, determining comfortable conditions for occupants and no-contaminated local atmosphere. The aircraft cabins are more confined and have a higher occupant density than other indoor environments such as offices or residential houses. The passengers and the crew share a closed and ventilated cabin, which brings potential risk ...