Technical Papers and Presentations

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 Heat and Mass Transport in a Nonlinear Catalytic Bed Reactor

A. Machac [1], R. Henda [2], and B. Nilsson [2]
[1] School of Engineering, Laurentian University, Sudbury, ON, Canada
[2] Lund University, Sweden

Heat and mass transport phenomena in a tubular catalytic bed reactor are numerically investigated. A two-dimensional pseudo-heterogeneous model, accounting for transport in the solid and fluid phases, with axial and radial dispersions, is used to describe the reactor. The calculation results show the development of a hot spot in the reactor. The effects of inlet process conditions are ...

A theoretical and experimental analysis of membrane bioreactors behavior in unsteady-state conditions

Curcio, S.
Department of Chemical Engineering and Materials University of Calabria, Rende (CS), ITALY

The behavior of hollow fiber membrane bioreactors operating in recycle configuration is characterized from both theoretical and experimental point of view. The theoretical model is based on the unsteady-state balance equations governing momentum and mass transfer within the regions that can be identified in a hollow fiber reacting system with immobilized enzyme, coupled to the unsteady-state mass ...

Computations on the coupled heat and mass transfer during fires in bulk materials, coal deposits and waste dumps

Krause, U., Schmidt, M., Lohrer, C.
Federal Institute for Materials Research and Testing (BAM), Division II.2 “Reactive Substances and systems”, Berlin, Germany

In porous combustible matter low-rate oxidation takes place at ambient conditions. In large stockpiles of bulk goods, coal heaps, waste dumps etc. it may occur that the heat released by the oxidation reaction is not fully transmitted to the surroundings but raises the temperature within the deposit. This triggers a positive feed-back loop since the oxidation rate increases with temperature. The ...

Fluid Flow and Heat Transfer Characteristics in a Stirred Cell System for Crude Oil Fouling

M. Yang[1], A. Young[1], and B. Crittenden[1]

[1]Department of Chemical Engineering University of Bath, Bath, United Kingdom

A small batch stirred cell which is operated at temperatures up to 400 °C and pressures up to 30 bar is used to study fouling behaviors of selected crude oils. COMSOL Multiphysics package is used for the CFD (Computational Fluid Dynamics) and heat transfer modeling for this stirred cell system. The simulation results are validated against the measured temperature data at various axial ...

Zur Kopplung zwischen Transport und chemischen Speziationsrechnungen mit FEMLAB®

Holzbecher, E.
Humboldt Universität Berlin, IGB, Berlin, GERMANY

In vielen Berechnungen des Umweltschutzes, der chemischen Verfahrenstechnik, der Energietechnik und weiteren Bereichen von Wissenschaft und Technik, spielen Transport- und Reaktionsprozesse gleichermaßen eine Rolle. Aufgrund der Wechselwirkung zwischen Transport und Reaktion ist das Verständnis derartiger Systeme schwierig. In der Regel werden daher Modelle eingesetzt, um derartige Situationen ...

Autothermal Reforming of a Hydrocarbon Fuel in a Monolithic Reactor

D. Creaser
Chalmers University of Technology, Sweden

In this paper, we perform simulations of the auto-thermal reforming of a hydrocarbon fuel in a monolithic reactor. The partial differential equations describing mass, heat and momentum transport were formulated and solved using COMSOL Multiphysics. It was found that mass transport limitations in the washcoat could also severely limit the rate of the reforming reaction. Heat transport ...

Acid-Base Reactions Enhancing Membrane Separation: Model Development and Implementation

C. Bayer[1], S. Stiefel[1], M. Follmann[1], and T. Melin[1]

[1]AVT Chemical Process Engineering, RWTH Aachen University, Aachen, Germany

Reactive extraction of organic acids from an aqueous solution to an alkaline stripping fluid is based on a selective barrier allowing permeation of non-polar molecules, which subsequently react with the stripping agent. The shift from the organic acid to its base induced by the chemical equilibrium enhances mass transfer inside the membrane’s porous substructure. A model of the porous layer ...

Study of the CO2 Transfer Rate in a Reacting Flow for the Refined Sodium Bicarbonate Production Process

C. Wylock[1], A. Larcy[1], P. Colinet[1], T. Cartage[2], and B. Haut[1]
[1]Université Libre de Bruxelles, Brussels, Belgium
[2]Solvay S.A., Brussels, Belgium

This work deals with the quantification of the CO2 transfer rate from a bubble to the surrounding liquid in a bubble column. A model is successfully developed using COMSOL Multiphysics. The validated model is used to study the enhancement influence of chemical reactions on the transfer rate. Moreover, the results of this study are compared with a classical 1-D approach and excellent comparison is ...

Simulation of Differential Ion Mobility (DMS) Principle Coupled with Mass Spectrometry in Atmospheric Pressure

F. Sinatra[1], T. Wu[2], A. Avila[2], E. Nazarov[1], T. Evans-Nguyen[1], J. Wang[2]
[1]Draper Laboratory, Tampa, FL, USA
[2]University of South Florida, Tampa, FL, USA

Mass spectrometry is an analytical technique widely used in the scientific community to determine chemical composition of sample compounds. Typically, mass spectrometers perform their analysis under vacuum conditions, though atmospheric pressure mass spectrometers are becoming more prevalent. With the development of atmospheric pressure mass spectrometers, techniques such as FAIMS (Field ...

Advancements in Carbon Dioxide and Water Vapor Separations Using COMSOL Multiphysics®

J. Knox[1], R. Coker[1], R. Cummings[1], C. Gomez[1], G. Schunk[1]
[1]NASA, Marshall Space Flight Center, Huntsville, AL, USA

Some NASA efforts are focused on improving current systems that utilize fixed beds of sorbent pellets by evaluating structured sorbents, seeking more robust pelletized sorbents, and examining alternate bed configurations to improve system efficiency and reliability. For the bulk separation of CO2 and H2O, temperature changes due to the heat of adsorption are significant, requiring modeling and ...

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