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 ...
J. Strong, and C. Washburn
Sandia National Laboratories
The newly emerging field of carbon-based MEMS (C-MEMS) attempts to utilize the diverse properties of carbon to push the performance of MEMS devices beyond what is currently achievable. Our design employs a carbon-carbon composite using nano-materials to build a new class of MEMS accelerometer that is hyper-sensitive over a dynamic range from micro-G to hundreds of G’s – far surpassing the ...
S. Anyyeva, and K. Kunisch
Institute of Mathematics and Scientific Computing
Karl Franzens University
We treat a gradient constrained minimization problem which has applications in mechanics and superconductivity. A particular case of this problem is the elastoplastic torsion problem. In order to solve the problem we developed an algorithm in an infinite dimensional space framework using the concept of the generalized Newton derivative. The Desktop environment of COMSOL Multiphysics 4.1 was ...
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 ...
Tohoku Institute of Technology
This paper is in Japanese.
I. Terechkine, T. Khabiboulline, D. Sergatskov
Fermi National Accelerator Laboratory, Batavia, IL, USA
Performance degradation of a superconducting RF cavity after quenching in an external magnetic field was calculated using COMSOL. This degradation is due to the increased resistance of a superconducting surface with trapped magnetic flux. The amount of the trapped flux depends on the size of the normally-conducting opening that develops in the superconducting wall of a cavity during quenching. ...
Modeling and Analysis of a Direct Expansion Geothermal Heat Pump (DX): Part I-Modeling of Ground Heat Exchanger
C. Rousseau, J. Fannou, L. Lamarche, M. Ouzzane
École de Technologie Supérieure, Montréal, Québec, Canada
CanmetENERGY, Varennes, Québec, Canada
Geothermal heat pump technology is actually one of the most interesting processes to provide heat and cold to a building. In this study, a model of the ground exchanger of a direct expansion geothermal heat pump (DX) is going to be presented in 1 dimension. The model represents the phase change of the refrigerant, here Chlorodifluoromethane R22, with governing continuity, momentum and energy ...
Modeling and Analysis of a Direct Geothermal Heat Pump (DX): Part II-Modeling of Water-Refrigerant Exchanger
J. Fannou, C. Rouseau, L. Lamarche, S. Kajl
École de Technologie Supérieure, Montréal, Canada
In this section, we simulate the heat exchanger system in one dimension characterized by two coaxial tubes with ribbed inner tube using the equations of conservation of mass, conservation of momentum and energy. The COMSOL PDE interface is used to simulate the monophasic and biphasic flow of refrigerant R22 (Chlorodifluoromethane). Heat transfer in waterand inner wall of the exchanger are ...
S. Curet, M. Mazen Hamoud-Agha
GEPEA, UMR 6144, CNRS, ONIRIS, Université de Nantes, Nantes, France
In this study, COMSOL®4.2a is used to model a microwave heating process in a TE10 rectangular waveguide. The sample consists of a small cylindrical Ca-alginate gel (D = 8 mm, H = 10 mm) inoculated with bacteria Escherichia Coli K12. The sample is placed along the microwave propagation direction into the waveguide. Maxwell’s equations and heat transfer are coupled to a microbial inactivation ...
G.E. Stebner, C. Hartwig
Ostfalia University, IMEC, Wolfenbüttel, Germany
In this paper an EMVD (Electro-Mechanical Valve Drive) for combustion engines is redesigned to achieve a fail-safe behavior when power loss occurs. The AC/DC Module and the Moving Mesh interface of COMSOL Multiphysics 4.2 are used to build up a transient model. This model also includes the calculation of eddy currents.