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 ...
N. Fillot, T. Doki-Thonon, and W. Habchi
CNRS, INSA, Université de Lyon, Lyon, France
Department of Industrial and Mechanical Engineering, Lebanese American University, Byblos, Lebanon
A ball is in contact with a plane, and a lubricant separates the two surfaces to decrease friction during their relative motion. To avoid wear, the lubricant film thickness should be higher than the surface roughness. The goal of this paper is to show how it is possible to solve efficiently the problem of elastohydrodynamics lubrication with COMSOL Multiphysics®, using a PDE (Partial ...
A. Montisci and R. Pintus
Department of Electrical and Electronic Engineering, University of Cagliari, Cagliari, Italy
The aim of the proposed device is to overcome the typical drawbacks of MHD generators, such as the needed of a very high external magnetic field, the strong dependency of the efficiency by the temperature of the fluid, and the deterioration of the electrodes that are in contact with the high temperature plasma. In fact the proposed device does not need an external magnetic fluid to work, but it ...
E. Gongadze, S. Petersen, U. Beck, and U. van Rienen
Institute of General Electrical Engineering, University of Rostock, Rostock, Germany
Institute of Electronic Appliances and Circuits, University of Rostock,
The Electrical Double Layer (EDL) plays a major role in understanding the interface between a charged surface (e.g. an implant) and ionic liquids (e.g. body fluids). The three classical models of the EDL (Helmholtz, Gouy, and Chapman-Stern) are numerically solved for a flat surface electrode in the 3D Electrostatics application mode of COMSOL Multiphysics® 3.5a. The values of the electric ...
A. Genoese, A. Genoese, and G. Garcea
Dipartimento di Modellistica per l'Ingegneria, Università della Calabria, Arcavacata di Rende, CS, Italy
Saint-Venant general rod theory is used to calculate the elastic factors of a section through the numerical solution of a system of partial differential equations. The elastic properties so evaluated are used in a geometric nonlinear analysis of 3D beam structures with general cross-section to calculate some important quantities such as the stiffness matrix. Linear solutions, such as the ...
C. Horch, S. Schlayer, and F. Stallmach
Faculty of Physics and Earth Sciences, University of Leipzig, Leipzig, Germany
For low-field NMR (Nuclear magnetic resonance), NdFeB permanent magnet arrangements are proposed to provide the static polarizing magnetic field. Especially a parallel and a circular arrangement of the permanent magnets, iron yokes and small shim magnets were tested and improved by COMSOL. The intent was to guide the design and the construction of NMR magnets by calculating the magnetic field ...
V.M. Rodriguez-Zermeno, M.P. Sørensen, N.F. Pedersen, N. Mijatovic, and A.B. Abrahamsen
DTU Mathematics, Lyngby, Denmark
DTU Electrical Engineering, Lyngby, Denmark
Materials Research Division, Risø, DTU, Roskilde, Denmark
This work presents a method to calculate AC losses in thin conductors such as the commercially available second generation superconducting wires through a multiscale meshing technique. The main idea is to use large aspect ratio elements to accurately simulate thin material layers. For a single thin superconductor, several standard test cases are simulated including transport current, externally ...
G.S. Durante and M. Fretz
CSEM Zentralschweiz, Alpnach Dorf, Switzerland
Flip-chip interconnection technologies have been tested through the use of a test chip with embedded single-bump daisy chains. The Flip-Chip technologies are selected among Au bump Thermocompression (TC) with and without Nonconductive Adhesives (NCA) underfiller, anisotropic conductive adhesive (ACA) bonding, and AuSn20 eutectic solder. The single bumps were then measured with a high precision ...
P. Bonfiglio and F. Pompoli
Materiacustica S.r.l., Ferrara, Italy
Engineering Department, University of Ferrara, Ferrara, Italy
The present work deals with a numerical investigation of resonating systems used for noise control applications. In literature one can find analytical models based on fluiddynamics concepts for evaluating losses occurring across the holes of the perforates. In the paper an acoustical formulation based on the equivalent dissipative fluid approach will be analyzed. It will be firstly applied to ...
T. Graf, O. Schälli, A. Furrer, and P. Marty
Technik und Architektur, Hochschule Luzern, Horw, Switzerland
This paper analyzes the magnetic behavior of electroplated wires. For this purpose the resistance and inductance of single turn loops and coils have been simulated and measured. The measurement is delicate due to the influence of a stray capacitance. We show that the quality factor of magnetic plated loops and coils can be tuned easily by the plating thickness. In addition the quality factor of ...