Articles techniques et présentations

Ici vous trouverez les présentations issues des Conférences COMSOL à travers le monde. Réalisées par des utilisateurs de COMSOL Multiphysics, ces présentations explorent tous les domaines actuels d'innovation. Les applications couvrent pratiquement tous les secteurs industriels et impliquent des phénomènes électriques, mécaniques, fluidiques et chimiques. Utilisez la recherche rapide pour trouver les présentations les plus intéressantes dans votre domaine d'intérêt.

Contact and No-Compression Analysis of a Human Spine Segment: Theory, Method and Parametric Investigation

P. Nédli1, G. E. Stavroulakis2, and M. Kurutz1
1 Department of Structural Mechanics, Budapest University of Technology and Economics, Budapest, Hungary
2 Institute of Computational Mechanics and Optimization, Technical University of Crete, Chania, Greece

Various two-dimensional models of lumbar spine segments, that is, lumbar functional spinal units (FSU) have been developed and studied here. FSU is the smallest part of the spine that has all the important features that the whole spine has. It consists of two adjacent vertebrae with the intervertebral disc between them and the surrounding ligaments.Since the spine segment has a symmetrical ...

Thermal Modeling of Devices Realizing Temperature Fixed-Points

V. Le Sant, and G. Failleau
Laboratoire National d'Essais, Paris, France

Within the framework of its thermal metrology activities and, in particular, in the context of a European project, LNE has recently developed a new device for the realization of the ITS-90 fixed-points with the aim of reducing uncertainties.Concurrently with this new device, a numerical thermal model has been developed, using COMSOL, to study heat transfer in temperature fixed points. This ...

Wave Energy Converter through Piezoelectric Polymers

A. S. Zurkinden1, F. Campanile1, and L. Martinelli2
1Swiss Federal Institute of Technology (ETH), Zürich, Switzerland
2Università di Bologna, Bologna, Italy

This note addresses the concept of wave energy conversion by means of a piezoelectric material. The ocean surface waves represent an important source of energy. A multiphysics simulation is used to focus on different aspects, namely the free surface wave, the fluid-structure interaction, the mechanical energy input to the piezoelectric material and the electric power output, using an equivalent ...

Analytical Methods for Reducing the Number of Independent Parameters Required to Model the Vocal Folds

D. D. Cook1, E. Nauman1, and L. Mongeau2
1Department of Mechanical Engineering, Purdue University, West Lafayette, IN, USA
2Department of Mechanical Engineering, McGill University, Montréal, QC, Canada

Mechanical tissue properties are required for reliable numerical models of the vocal folds. In this study, criteria for determining the compatibility of tissue property values obtained from independent studies are presented.Two methods for reducing the number of independent material parameters are given. The errors introduced by these assumptions were quantified by performing a modal analysis on ...

Modeling a Microscale Proportional Flow Controller

H. Prentice-Mott, D. Irimia, A. Russom, and M. Toner
Center for Engineering in Medicine (BioMEMS Center), Massachusetts General Hospital, Charlestown, MA, USA

Microfluidics is able to provide many benefits to the fields of biology and chemistry through its ability to use small amounts of fluid and to finely control the environment of the experiment. However, the precision of the flow rate control at the microscale remains limited to either off-chip variable-flow-rate pumps or on-chip valves.Here, we report an on-chip pneumatic valve that allows for ...

Overcoming the Diffusion Barrier: Ultra-Fast Micro-Scale Mixing via Ferrofluids

L. Mao, and H. Koser
Department of Electrical Engineering, Yale University, New Haven, CT, USA

We report on the design and simulation of a novel, micro-scale mixing device based on stable water suspensions of magnetic nanoparticles (i.e. ferrofluids). In this paper, a two dimensional COMSOL Multiphysics simulation including time domain electromagnetics, fluid dynamics, diffusion and convection, and user-defined PDEs is used to study the mixing efficiency of the ferrohydrodynamic ...

Computation of Airfoils at Very Low Reynolds Numbers

D. Bichsel1, and P. Wittwer2
1HESSO, Ecole d'Ingénieurs de Genève, Geneva, Switzerland
2DPT, Université de Genève, Geneva, Switzerland

We discuss a new numerical scheme involving adaptive boundary conditions which allows to compute, at very low Reynolds numbers, drag and lift of airfoils with rough surfaces; efficiently and with great precision.As an example, we present the numerical implementation for an airfoil consisting of a line segment. The solution of the Navier-Stokes equations is singular at the leading and trailing ...

Two-Phase Modeling of Gravity Drainage of Bitumen from Tar Sand Using In-Situ RF Electrical Heating

A. Hassanzadeh
Pyrophase Inc., Chicago, IL, USA

In-situ electrical heating technologies are among the most recent technologies used for bitumen recovery from tar sand and oil shale. These technologies have limited environmental impact because there is little disturbance of the land, and water and solvents are not used. Two-phase movement of bitumen and air in tar sand porous deposit is modeled using COMSOL Multiphysics. A system of non-linear ...

Modeling Nanoscale Heat Flow

S. Palaich, and B. Daly
Physics and Astronomy Department, Vassar College, Poughkeepsie, NY, USA

When the dimensions of the material approach is a comparable size to the phonon mean free path, heat flow enters a new regime, the nanoscale. The Fourier and Cattaneo Equations describe bulk heat flow well, but radiative boundary terms must be considered when modeling nanoscale heat flow. We take these equations and input them into COMSOL with the hope of eventually linking nanoscale and bulk ...

Optimization of an Electromagnetic Actuator with COMSOL Multiphysics

T. Müller[1], A. Schwenger[2], and H. Haase[1]
[1]Institut für Grundlagen der Elektrotechnik und Messtechnik, Leibniz Universität Hannover, Germany
[2]Volkswagen AG, Germany

This paper describes the automatic optimization of an electromagnetic actuator using a genetic algorithm.  The actuator modeled here is dedicated for charge changing valve actuation in internal combustion engines. In the first step of the simulation, several operating points are calculated using the script language of COMSOL Multiphysics. In order to reduce computation time, only one segment of ...

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