Presentazioni e Articoli Tecnici
Simulation of a Heated Tool System for Jet Electrochemical Machining
M. Hackert[1], G. Meichsner[2], and A. Schubert[1][2]
[1]Chair Micromanufacturing Technology, Faculty of Mechanical Engineering, Chemnitz University of Technology, Chemnitz, Germany
[2]Fraunhofer Institute for Machine Tools and Forming Technology, Chemnitz, Germany
Jet Electrochemical Machining (Jet-ECM) is an unconventional procedure using localized anodic dissolution for micromachining. An increasing of the electrolyte temperature will lead to an increase of the electrical conductivity of the electrolyte by about 30% and to a reduction of the dynamic viscosity of the electrolyte by about 25 %. Both will improve the process. Therefore a Jet-ECM tool system ...
Numerical Study of an LTD Stirling Engine with Porous Regenerator
N. Martaj[1], P. Rochelle[1][2], L. Grosu[1], R. Bennacer[3], and S. Savarese[4]
[1]Universitè de Paris, Paris, France
[2]Institut Jean Le Rond d'Alembert, Université Paris 6
[3]Laboratoire LEEVAM «Environnement, Energétique, Valorisation, Matériaux», Universitéde Cergy-Pontoise
[4]COMSOL France, 5 pl. R Schuman, 38000 Grenoble
The alternative engines of Stirling type, are engines running on "hot air", using both an external heat source and regeneration. They should be considered as an alternative for the effective conversion of renewable energy sources into work, with their theoretical yield equal to the theoretical Carnot limit. The output efficiency and the power of these engines are strongly related to the ...
Cascades of Secondary Particles in High Voltage Accelerators
M. Cavenago[1], P. Antonini[1][3], P. Veltri[2], N. Pilan[2], V. Antoni[2], and G. Serianni[2]
[1]INFN-LNL, Legnaro, Padova, Italy
[2]Consorzio RFX, Padova, Italy
[3]Centro Ric. E. Fermi, Roma, Italy
A very simplified system for high voltage test is studied, considering reason for voltage holding failures which are not covered by conventional and local design criteria. A first understanding of the problem is obtained by solving the electrostatic potential in a 2D axis symmetric geometry, considering in detail the electrode shapes, and following a cascade of particle between opposite ...
Simulation of Transport of Lipophilic Compounds in Complex Cell Geometry
Q.A. Chaudhry[1], M. Hanke[1], and R. Morgenstern[2]
[1]School of Computer Science and Communication, Royal Institute of Technology, Stockholm, Sweden
[2]Karolinska Institutet, Stockholm, Sweden
The mathematical modeling of the diffusion and reaction of toxic compounds in mammalian cells is tough task due to their very complex geometry. The heterogeneity of the cell, particularly the cytoplasm, and the variation of the cellular architecture, greatly affects the behavior of these toxic compounds. Homogenization techniques have been implemented for the numerical treatment of the model. ...
Numerical Simulation of the Functional Electromagnetic Stimulation of the Human Femoral Bone using COMSOL
Y. Haba[1], W. Kröger[2], H. Ewald[2], R. Souffrant[1], W. Mittelmeier[1], and R. Bader[1]
[1]Biomechanics and Implant Technology Research Laboratory, Department of Orthopaedics, University of Rostock, Rostock, Germany
[2]Institute of General Electrical Engineering, University of Rostock, Rostock, Germany
In the present study we determined the relative conductivities and permittivities of fresh cortical and cancellous bone measuring human femoral heads in different slices of 1 mm thickness. The identified conductivities of human trabecular bone are used for the electromagnetic field simulation by means of COMSOL using a Micro-Computed Tomography (Micro-CT) model. The calculated model depends on a ...
Control of Rolling Direction for Released Strained Wrinkled Nanomembrane
P. Cendula[1], S. Kiravittaya[1], J. Gabel[1], and O.G. Schmidt[1]
[1]Institute for Integrative Nanosciences, Dresden, Germany
Strained wrinkled and flat nanomembranes have different bending properties when they are released from the underlying substrate. This is caused by increased bending rigidity of the wrinkled film in one direction. We provide theoretical and numerical analysis of the directional rolling of wrinkled films, which is important for positioning rolled-up tubes on the short mesa edge during fabrication.
An Extension of Lauwerier’s Solution for Heat Flow in Saturated Porous Media
S. Saeid[1] and F.B.J. Barends[2]
[1]Technical University of Delft, Delft, The Netherlands
[2]Deltares and TU-Delft, Delft, The Netherlands
One of the crucial topics in this century is sustainable energy. In this respect, the exploitation of geothermal energy from deep hot aquifers becomes opportune. Hence, insight is required in the heat balance of potential aquifer systems. Essential issues are convection, conduction and dispersion. This article focuses on Lauwerier’s problem. As an extension, it is suggested that beside ...
Growth and Remodelling of Intracranial Saccular Aneurysms
A. Di Carlo[1], V. Sansalone[2], A. Tatone[3], and V. Varano[1]
[1]Modelling and Simulation Lab, Università Roma Tre, Roma, Italy
[2]Laboratoire de Mécanique Physique, Université Paris Est, Paris, France
[3]DISAT, Università degli Studi dell’Aquila, L'Aquila, Italy
We present a mechanical model a growing spherical shell suitable for predicting the evolution of a Saccular Cerebral Artery Aneurysms (SCAA). It relies basically on the Kröner-Lee decomposition, used to describe the interplay between the current and the relaxed configuration of body elements. Rupture or stabilization of a SCAA are the end effect of a number of biological mechanisms, still poorly ...
Modeling Contaminant Diffusion in Highly Complex Rock Structures
N. Diaz[1], A. Jakob[1], L. Van Loon[1], and D. Grolimund[2]
[1]Paul Sherrer Institut NES/LES, Villigen PSI, Switzerland
[2]Paul Sherrer Institut NES/SLS, Villigen PSI, Switzerland
Opalinus clay is currently being proposed as a potential host rock for radioactive waste repository in deep geological formation. It is then important for performance assessments to understand the transport properties of such rocks. Clay materials are characterized by low hydraulic conductivities and diffusion is assumed to be the main transport mechanism. The studied rock is a complex assembly ...
