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.

Modeling of Lead-acid Flow Battery

M. N. Nandanwar[1], S. K. Gupta[1]
[1]Indian Institute of Science, Bangalore, India

Failure of conventional lead-acid battery is attributed to degradation of solid active mass (PbO2 and PbSO4 ). A number of research efforts are underway worldwide to overcome degradation of active mass to improve the cycle life of lead-acid batteries. Soluble lead-acid flow battery (SLFB) is a new kind of lead-acid flow battery in which products of discharge remain in dissolved state. SLFB ...

Improving Fuel Usage in Microchannel Based Fuel Cells

P. Fodor, and J. D'Alessandro
Dept. of Physics
Cleveland State University
Cleveland, OH

In this work a miniaturized fuel cell design based on microchannels, into which the liquid fuel and oxidizer streams are fed through T shaped connectors, is optimized for improved fuel usage. This particular design exploits the laminar nature of the fluid flow at small Reynolds numbers to keep the fuel and oxidizer confined in the vicinity of the corresponding electrodes without the need of a ...

Fluid Flow and Current Density Distribution in Large-area HT PEMFCs

G. C. Bandlamudi[1,2], C. Siegel[2], C. Heßke[1], and A. Heinzel[1,2]
[1]ZBT Duisburg, Duisburg, Germany
[2]University of Duisburg-Essen, Duisburg, Germany

High temperature polymer electrolyte membrane fuel cells (HT PEMFCs) are very promising technologies when used in combined cooling and heating power (CCHP) systems. They are operated at 160°C, offering the possibility of high tolerance to fuel impurities and a possibility to use the heat generated for cooling and heating purposes, leading to higher total system efficiency. Employing a 24 ...

Computational Modelling of Fluid Dynamics in Electropolishing of Radiofrequency Accelerating Cavities - new

H. Rana[1], L. Ferreira[2]
[1]Loughborough University, Leicestershire, UK
[2]European Organisation for Nuclear Research (CERN), Genéve, Switzerland

Electropolishing is an electrochemical process that radiofrequency accelerating cavities undergo in order to improve their inner metal surface finishing. This is performed prior to their installation into particle accelerators, in order to enhance their accelerating properties. Using COMSOL Multiphysics® software it was possible to model the process throughout the cavity and study the fluid ...

Optimization of an Electrochemistry System

D. Mi [1],
[1] KEISOKU Engineering System Co., Ltd., Chiyoda-ku, Tokyo, Japan

Optimization of a typical electrochemical system with insulating shields is considered in this work, which objective is to reduce the current peak due to singularity and smooth the current density distribution along electrode surface. Moving mesh method was adopted to allow change in design variables, i.e., position and width of the insulating shields. It was found that combining optimization ...

Screening Effects in Probing the Electric Double Layer by Scanning Electrochemical Potential Microscopy

R.F. Hamou[1], P.U. Biedermann[1], A. Erbe[1], and M. Rohwerder[1]
[1]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 ...

Modeling of a Direct Methanol Fuel Cell

J. Drillet [1],
[1] DECHEMA-Forschungsinstitut, Frankfurt, Germany

This work aims at the modelling of a 5 cm^2 Direct Methanol Fuel Cell (DMFC) with mixed serial/parallel serpentine flow fields in terms of current/voltage behavior. One of the main challenge to overcome consists on lowering the so-called methanol cross over from the anode through the polymer membrane to the cathode that is responsible for mixed-potential formation at the cathode where both ...

Uniform Reaction Rates and Optimal Porosity Design for Hydrogen Fuel Cells

J. H. Al-Smail [1]
[1] King Fahd University of Petroleum & Minerals, Dhahran, Saudi Arabia

We develop a porosity-optimization problem to improve the electrochemical reactions taking place in hydrogen fuel cells. We introduce a mathematical model, which involves a system of conservation laws defined in a porous space domain. Our goal is to find the domain's optimal porosity function that can make the oxygen-hydrogen reaction as uniform as possible. The optimal porosity design ...

Current Density Simulations in the Electrodeposition from Ionic Liquids: Effects of the Conductivity

I. Perissi[1], C. Borri[1], S. Caporali[1], and A. Lavacchi[1]
[1]Department of Chemistry, University of Firenze, Sesto Fiorentino, FI, Italy

The overall goal of this work is the use of COMSOL Multiphysics® in the modeling of the current density distributions for the electrodeposition of aluminum coatings from ionic liquids. The local current distribution is strongly dependant on the conductivity and on the geometry of the galvanic cell and can only be computed by the numerical solution of the partial differential equations ...

Rechargeable Battery for Hybrid Diesel-Electric Locomotive

Michael A. Vallance
Team Leader, GE Global Research

Over time, rechargeable batteries degrade and eventually stop working. You see some combination of declining capacity, rapid self-discharge, and reduced power. Degradation mode depends on battery design, but also on the application. Often, multiple physical processes contribute to degradation. In the laboratory, you can measure performance degradation. You can dissect the battery to discover ...