In questa sezione troverete i lavori presentati alle Conferenze mondiali COMSOL. Le presentazioni descrivono ricerche e prodotti innovativi progettati con COMSOL Multiphysics da colleghi di tutto il mondo. I temi delle ricerche presentate abbracciano un'ampia gamma di settori produttivi e aree applicative, in ambito elettrico, meccanico, fluidodinamico e chimico. Lo strumento di Ricerca Rapida vi permetterà di trovare le presentazioni che si riferiscono all'area di vostro interesse.

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 ...

Permanent Magnet Arrangements for Low-Field NMR

C. Horch[1], S. Schlayer[1], and F. Stallmach[1]
[1]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 ...

Static and Dynamic Simulation of an Electromagnetic Valve Actuator Using COMSOL Multiphysics®

R. Wislati[1] and H. Haase[1]
[1]Institut für Grundlagen der Elektrotechnik und Messtechnik, Leibniz Universität Hannover, Hannover, Germany

In this paper an Electromagnetic Solenoid Actuator (EMVA) consisting of an upper and lower electromagnet, a linear moving armature and two preloaded springs is considered as a potential approach in Variable Valve Actuation (VVA) systems for internal combustion engines. The analysis of the upper electromagnet has been performed using Finite Element Method (FEM) simulation. Thereby an axially ...

Fast 2D Simulation of Superconductors: A Multiscale Approach

V.M. Rodriguez-Zermeno[1], M.P. Sørensen[1], N.F. Pedersen[2], N. Mijatovic[2], and A.B. Abrahamsen[3]
[1]DTU Mathematics, Lyngby, Denmark
[2]DTU Electrical Engineering, Lyngby, Denmark
[3]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 ...

Using COMSOL Multiphysics® for Biomechanical Analysis of Stent Technology in Cerebral Aneurysms

J. Rasmussen[1], M.S. Enevoldsen[1], J. Thyregod[2], and K-A. Henneberg[1]
[1]Department of Electrical Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark
[2]COOK Medical Europe, Bjaeverskov, Denmark

This work presents new Fluid-Structure Interaction (FSI) models in both 2D and 3D of the effect of using vascular stents as treatment of cerebral berry aneurysms. The stent is positioned inside the cerebral artery covering the neck of the aneurysm. The stent is expected to alter the blood flow into the aneurysm such that the blood coagulates due to low blood velocity, and rupture of the aneurysm ...

Measuring and Calculation of Positive Corona Currents Using COMSOL Multiphysics®

M. Quast[1] and N.R. Lalic[1]
[1]Gunytronic GmbH, St Valentin, Germany

The sensor type developed by Gunytronic uses corona discharge for measuring flow rates in exhaust streams of automotives, aircrafts and industrial plants. This paper will present the development of testing equipment used in laboratory for investigating physical relations on corona currents, charged particle transport, the calculation of the collateral electric fields and high potentials. This ...

Design and Simulation of a Microscale Magnetophoretic Device for the Separation of Nucleated Fetal Red Blood Cells from Maternal Blood

G. Schiavone[1], D.M. Kavanagh[2], and M.P.Y Desmulliez[2]

[1]Politecnico di Torino, Torino, Italy
[2]MIcroSystems Engineering Centre, School of Engineering & Physical Sciences, Heriot-Watt University, Edinburgh, Scotland, United Kingdom

Intense research has been carried out into methods that aim at harvesting fetal cells from maternal blood as substitutes to amniocentesis and chorionic villus sampling. This work focuses on the separation of fetal nucleated red blood cells from the maternal circulation based on their intrinsic magnetic properties. The design and simulation of a magnetophoretic separator is described, as it will ...

Model of Heat and Mass Transfer with Moving Boundary During Roasting of Meat in Convection-Oven

A.H. Feyissa[1], J. Adler-Nissen[1], and K.V. Gernaey[2]
[1]Food Production Engineering, National Food Institute, Technical University of Denmark, Kgs. Lyngby, Denmark
[2]Department of Chemical and Biochemical Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark

A 2D mathematical model of coupled heat and mass transfer describing oven roasting of meat was formulated from first principles. The current formulation of model equations incorporates the effect of shrinkage phenomena and water holding capacity. The model equations are based on conservation of mass and energy. The pressure driven transport of water in meat is expressed using Darcy’s equation. ...

Guided Wave in Engineering Structures Using Non-Contact Electromagnetic Acoustic Transducers: A Numerical Approach for the Technique Optimisation

S. Soua[1], A. Raude[1], and T-H. Gan[1]
[1]NDT Technology Group, TWI Ltd, Cambridge, United Kingdom

There are over 10 million kilometers of pipes and pipelines around the world that carry hazardous fluids and gases. Fluids include oil, oil products, chemicals such as solvents, caustics, acids, corrosives and combustibles often at high pressure and temperature. These pipes are susceptible to corrosion if they are not protected properly by the environment or the contents. Inspection of pipes is ...

Multi-Objective Optimization of a Ball Grid Array Using modeFRONTIER® and COMSOL Multiphysics®

H. Strandberg[1], T. Makkonen[2], and J. Leinvuo[2]
[1]ESTECO Nordic AB, Lund, Sweden
[2]VTI Technologies Oy, Vantaa, Finland

Capacitive MEMS (Micro-Electro-Mechanical Systems) accelerometers may be directly soldered to the printed circuit board by an array of solder balls. Differences in the thermal expansion coefficients of the pertinent materials cause deformations of the accelerometer under temperature change. This may cause a relative movement of the sensing masses with respect to the sensing electrodes, resulting ...