A. Melas, A.G. Konstandopoulos, L. Isella, Y. Drossinos
Department of Chemical Engineering, Aristotle University, Thessaloniki, Greece
European Commission, DG Energy, Luxemburg
European Commission, Joint Research Centre, Ispra, Italy
Aerosol and colloid aggregates are complex fractal-like structures composed of primary spheres. The drag force exerted on a fractal-like object is usually determined by solving numerically the Stokes equation. In this study we calculate it by relating it to a molecule-aggregate collision rate. We create the fractal aggregates with a cluster-cluster aggregation algorithm using the software ...
M. Bianchi Janetti, F. Ochs
University of Innsbruck, Innsbruck, Austria
Introduction: The simulation of coupled heat and moisture transfer in constructions is becoming even more important in the last years. COMSOL Multiphysics represents a powerful tool for this kind of simulations as shown in [1,2,3], although applications in this area are still rare. For the realistic prediction of the heat and moisture distribution in building elements exposed to external climatic ...
F. Maier, P. Oberdorfer, I. Kocabas, I. Ghergut, M. Sauter
Dpt. Applied Geology, Center of Geosciences, Georg-August-University, Göttingen, Germany
Petroleum and Natural Gas Engineering Department Batman, Batman University, Batman, Turkey
We compare the output of 2D single fracture models as well as analytical solutions of the problem. The temperature signal is evaluated with the heat transfer mode while the flow field is assumed to exhibit Darcy flow everywhere. The problem is time-dependent so we have to take into account a change in the boundary conditions from a Dirichlet to a Neumann condition which is activated at the time ...
Coupled Heat and Moisture Transfer in Building Components - Implementing WUFI® Approaches in COMSOL Multiphysics
B. Nusser, M. Teibinger
Holzforschung Austria, Vienna, Austria
Calculating time-dependent heat and moisture transports trough building components are important tasks in the area of building physics. A well known and worldwide used commercial software for this is WUFI®. From the scientific point of view the restricted access to governing equations is nevertheless a drawback of this software. In the present paper it is shown how the physical approaches used ...
Numerical Simulations of Methane Aromatization with and without a Ceramic Hydrogen Separation Membrane
Z. Li, C. Kjølseth, S. Hernandez Morejudo, R. Haugsrud
University of Oslo, Department of Chemistry, FERMiO, Oslo, Norway
Protia, Oslo, Norway
University of Oslo, Department of Chemistry, InGAP, Oslo, Norway
Oxygen-free methane aromatization has been attracting growing attention due to a potential means for producing high valuable products such as aromatics and hydrogen. Many studies have been focused on catalysts screening and characterization, and elementary thermodynamic steps of the reaction. However, little attention has been paid to fluid dynamics which are important for an industrial ...
C. Grau Turuelo, B. Bergmann, C. Breitkopf, F. Hoffmann, L. Brencher
Technische Universität Dresden, Dresden, Saxony, Germany
Infineon Technologies GmbH, Dresden, Dresden, Saxony, Germany
A novel technique for semiconductor manufacturing is introduced: Silicon-On-Nothing. This process consists of an initial cylindrical trench which has a shape evolution under certain conditions: high temperature (1100 °C), low pressure (10 Torr) and a non-oxidizing atmosphere such as hydrogen. These conditions enable a, mainly, surface diffusion phenomenon whose final result is an empty space ...
O. Rouaud, T. Pham
LUNAM Université, ONIRIS, CNRS, GEPEA, UMR, Nantes, France
University of New South Wales, Sydney, Australia
A mathematical model is developed to determine the weight loss and the freezing rate during the freezing of unwrapped foodstuffs. The model allows comparing two freezing processes; the first uses nitrogen gas at -80°C and the second uses cold air. The model includes thermophysical properties that are temperature dependent to take into account the ice formation. The time step has to be chosen ...
Eindhoven University Of Technology, Eindhoven, The Netherlands
Windows are the thermal weakest places in the external envelop of buildings. This is true for historic windows with original single pane glazing in historic buildings. To reduce the energy consumption and to improve thermal comfort of historic buildings, replacing these windows by modern double glazed windows affects the authentic character of these buildings too much. One way to improve the ...
E. Holzbecher, S. Oehlmann
Georg-August Universität Göttingen, Göttingen, Germany
Phenomena of heat and mass transfer are often compared, in various porous media applications. Questions of practical interest are, for example, if tracers can be used for the prediction of heat flow, or vice versa if heat can be utilized as, possibly retarded, tracer for predicting the migration of contaminants, nutrients or other substances. Using numerical modelling in artificial porous media ...
C. Hurt, P. Angelo, R. Pevey
Department of Nuclear Engineering, University of Tennessee, Knoxville, TN, USA
Y-12 National Security Complex, Safety Analysis Engineering, Oak Ridge, TN, USA
Simulation of criticality accident transients offers the ability to confirm understanding of critical configurations, bound accident scenarios and aid comprehensive emergency planning. Computational ability to recreate excursion power histories in fissile solution is sought due to the predominance of solutions in process criticality accidents. Applicable solution transient physics methodologies ...