A. Cantu-Perez, S. Ping Kee, and A. Gavriilidis
University College London, Department of Chemical Engineering, Torrington Place, London, UK
The mixing characteristics and residence time distributions (RTDs) of a staggered herringbone microchannel have been investigated numerically by COMSOL Multiphysics and by particle tracking algorithms that incorporate diffusion via a random walk. All simulations were validated with experimental data. It was found that for low Peclet numbers the use of herringbone structures have little impact on ...
Time-Resolved Optical Tomography in Preclinical Studies: Propagation of Excitation and Fluorescence Photons.
F. Nouizi, R. Chabrier, M. Torregrossa, and P. Poulet
Laboratoire d’Imagerie et de Neurosciences Cognitives, Straßbourg, France
Laboratoire des Sciences de l'Image, de l'Informatique et de la Télédétection, France
We present time-resolved methods that rely on near-infrared photons to image the optical properties and distribution of fluorescent probes in small laboratory animals. The coupled diffusion equations of excitation and fluorescence photons in highly scattering tissues were solved using the three-dimensional Finite Element Method (FEM) provided by COMSOL. The computed results allowed to yield ...
A. Weddemann, and V. Thümmler
Bielefeld University, Germany
ALE-methods are frequently used to solve systems of partial differential equations (PDEs) on moving domains. The main idea of these methods is to incorporate the time evolution of the domain into the equations. However, the motion of the domain with respect to time induces convective fluxes in the resulting equations. These can lead to stability problems of the numerical method if they become ...
Multiphysics Simulation of Thermoelectric Systems - Modeling of Peltier-Cooling and Thermoelectric Generation
Fraunhofer-Institute for Physical Measurement-Techniques (IPM), Freiburg, Germany
Electro-thermal interaction is commonly considered only as a matter of joule heating. In addition, the Seebeck-, Peltier- and Thompson-Effects are significant in materials with high thermoelectric figure of merit Z. These thermoelectric materials have a high Seebeck-coefficient α, a good electric conductivity σ, and a poor thermal conductivity λ. They have widespread areas of ...
J. Wirth, S. Jack, M. Köhl, and K.-A. Weiß
Fraunhofer Institute for Solar Energy Systems ISE, Freiburg, Germany
The key issues of the Fraunhofer Institute for Solar Energy Systems are research and development of solar technologies for the fast growing market of solar energy. This paper presents examples of the usage of COMSOL Multiphysics: The ingress of water is a serious reason for the degradation of photovoltaic modules which can hardly be measured using experimental approaches yet. Therefore, a ...
H. Pakdast, Z. Davis
DTU Nanotech, Technical University of Denmark, Kgs. Lyngby, Denmark
This article describes the development of a bulk mode resonator which can be employed for detection of bio/chemical species in liquids. The goal is to understand the mechanical and electrical properties of a bulk mode resonator device which exhibit high frequency resonance modes and Q-factor. A high resonance frequency is desirable because a small change in the resonator’s mass, for ...
Dipartimento di Energetica “Sergio Stecco”, Università degli Studi di Firenze, Firenze, Italy
This paper presents and discusses the first phase results of a wide ranging project concerning the study and prediction of the efficiency and energy performances of natural ventilation systems existing inside historic buildings. The air flow patterns, air temperature and air velocity distribution inside a historic building in Florence, the Pitti Palace, were studied by a transient simulation. A ...
J. Torres, and D. Montane
Centre Huile Lourde Ouvert et Experimental (CHLOE), University of Pau, France
Department of Chemical Engineering, Virgili University, Tarragona, Spain
Steam Reforming of Ethanol using a Catalytic Wall Reactor (CWR) was successfully studied using COMSOL Multiphysics. A mathematical model was used to describe the reactor performance in terms of the main variables and dimensionless groups. Simulations showed that at specified conditions CWR maintains a thermal performance adequate for evaluating catalysts under a uniform temperature profile. CWR ...
O. Geoffroy, and H. Rouch
INOPRO, Villard de Lans, France
The crystal growth industry uses high temperature processes. To improve production efficiency, a good knowledge of thermal effects is necessary. We show in this article a methodology to get reliable data by mixing simplified models, sensitivity studies and parameters adjustments. The precision is improved by comparison with experimental measurements.
A. Auge, F. Wittbracht, A. Weddemann, and A. Hütten
Department of Physics, University of Bielefeld, Germany
Transport phenomena in spatially periodic magnetic systems, in particular the directed transport of magnetic beads in a so called magnetic ratchet (Brownian motor) are considered. Simulations are carried out to test and optimize this system, where the Smoluchowski equation with flux terms for the magnetic and gravitational force is used. Furthermore, experiments are carried out to verify the ...