J. Hrdlicka, P. Cervenka, and D. Snita
Institute of Chemical Technology Prague, Prague, Czech Republic
This contribution is devoted to the mathematical modeling of the AC electroosmotic micropumps in COMSOL Multiphysics and Matlab. The mathematical model involves the microchannel surroundings and several AC-voltage driving modes. The weak form has been used for handling singularities and other problems. The system dynamic behavior and conditions at the phase interfaces will be discussed.
J.M. Gozalvez-Zafrilla, M.C. Leon-Hidalgo, J. Lora-Garcia, A. Santafe-Moros, and J.C. Garcia-Diaz
Universidad Politecnica de Valencia, Valencia, Spain
Brine disposal from desalination plants placed in inland areas far from sea is an important problem. Evaporation ponds can be used for reducing the waste to solid state but they require huge amounts of land. Evaporation using arrays of wet surfaces can minimize the land requirements. One characteristic of the methods based on natural evaporation is the uncertainty associated to the influent ...
E. Evgin, J. Infante Sedano, and Z. Fu
University of Ottawa
This paper is a part of a study on energy piles for heating and cooling of buildings. Energy piles are used for two reasons: (1) to transfer structural loads to foundation soils, and (2) to transfer heat from foundation soils to the building for space heating in winter time and for cooling purposes in summer time by transferring heat from the building to the foundation soils. The efficiency of ...
A. Weddemann, D. Kappe, and A. Hütten
Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge MA, USA
Department of Physics, Thin Films and Physics of Nanostructures, Bielefeld University, Bielefeld, Germany
In principal, the calculation of the magnetic state inside a magnetic object requires the evaluation of the field in the entire unbounded space. With finite element methods restricted to finite domains, commonly auxiliary domains are employed which result in a non-physical cut-off. Not only that these additional domains result in an increased number of degrees of freedom which are strictly ...
C. Romao, and M. White
Dept. of Chemistry and Institute for Research in Materials
A series of 2-D finite element models of a ZrO2-ZrW2O8 composite system were created in COMSOL Multiphysics to study the effect of pores between the matrix (ZrO2) and filler (ZrW2O8) materials. Pores were modeled as ellipses concentric with the filler particles. Seventeen model geometries of varying microstructure were studied in order to determine correlations between microstructural ...
P. Oberdorfer, F. Maier, and E. Holzbecher
The efficiency of borehole heat exchangers (BHEs) for geothermal purposes depends not only on material properties but also on their geometrical design. These days most used design consists of two parallel arranged U-shaped pipes which are embedded in a high-conductive shell filling out the borehole. Another common design is a pipe inside of another pipe, with fluid flowing down inside and up ...
Optimization of a High-Temperature High-Pressure Direct Wafer Bonding Process for III-V Semiconductors
R. Martin, J. Kozak, K. Anglin, and W. Goodhue
University of Massachusetts Lowell
Many optoelectronic devices utilize a heterojunction of a pair semiconducting materials including high-efficiency MEMS devices, solar cells, LEDs, and VCSELs. One fabrication technique which achieves such a device is direct wafer fusion. To optimize the process, COMSOL Multiphysics 4.0 was used to test various geometric configurations of the fixture. 2D and 3D models were created in order ...
Using Comsol 4.1 to Build a Transient Model of a Drift Tube Ion Mobility Spectrometer with Improved Performance
J. Langejürgen, P. Cochems, U. Günay, M. Allers, and S. Zimmermann
Leibniz University Hannover
An Ion Mobility Spectrometer is a device to analyze different components of a gas mixture. A feature of this technology is the ultra-low detection limit which can be obtained for most trace gases. Due to a limited resolution which is needed to differ between different components an improvement of the IMS field geometry is needed. Especially for novel ionization sources the influence of Coulomb ...
Modeling of Coupled Fluid Flow and Shear-induced Solidification Kinetics in Rheocasting of Aluminium Alloys
G. Maizza, and G. Lorenzatto
Politecnico di Torino
Dipartimento di Scienza dei Materiali ed Ingegneria Chimica
The model proposed by Schneider et al., for polymers is herein adapted in order to assess its suitability in elucidating the thixotropic behavior of aluminum alloys. The COMSOL Multiphysics program is employed to solve the inherent coupled mathematical problem, consisting in the kinetic ordinary differential equations and the momentum and energy transport partial differential equations. The ...
H. van Halewijn
Eindhoven, The Netherlands
For the educational program of Fluid Dynamics at the Fontys Hogeshool of Applied Physics, a wind tunnel was developed for tests of flow profiles of objects, such as a ball, cube or plate. Students are expected to measure the air resistance of a variety of objects, and verify the measurements with the turbulent CFD module of COMSOL. The measurements and the COMSOL simulations match nicely, and ...