M. Cavenago, P. Veltri, E. Gazza, G. Serianni, and P. Agostinetti
INFN-LNL, Legnaro, Padova, Italy
Consorzio RFX, Padova, Italy
The development of powerful negative ion sources requires precise and versatile simulation tools to predict the emittance of the extracted ion beams and the heat load on the electrodes. A first tool is a determination of the plasma beam interface which is accomplished by a set of macro based in the COMSOL Multiphysics environment. Notwithstanding the strong nonlinearities involved, a proper ...
Q. Li, and S. Seelecke
Department of Mechanical & Aerospace Engineering, North Carolina State University, Raleigh, NC, USA
This presentation deals with a Thermomechanical coupled analysis of a Shape Memory wire actuator. The outline for the Shape Memory Alloy model is:Motivation - Multiple scales and materialsMicro-scale mechanismsMeso-scale lattice elementsMacro-scale elementFree energy conceptUnified approach to various active materials(SMA, PZT, FSMA, etc.)Mathematical modelStatistical thermodynamicsThermally ...
M. Ek, and D. Sichen
Materials Science and Engineering, Royal Institute of Technology, Stockholm, Sweden
In the steelmaking processes, the stirring of the metal bath by argon (or nitrogen) injection is a widely used method to achieve chemical or thermal homogeneity. Computational fluid dynamics can be used as a very powerful tool to gain an insight into the mass transfer and heat transfer in liquid steel. In this paper, the flow behaviors in two different steelmaking reactors were simulated using ...
Laminar Fluid Flow and Heat Transfer Studies of an Electrical Conducting Fluid Subject to Combined Electric and Magnetic Fields
E. Gutierrez-Miravete, T. DePuy, and X. Xie
Rensselaer at Hartford, Hartford, CT
Pratt & Whitney, East Hartford, CT
The flow of electrically conducting fluids such as liquid metals is significantly affected by applied electric and magnetic fields. The effect has important industrial applications in metallurgy, nuclear technology and other fields. This paper described results of a series of studies designed to investigate the capabilities of COMSOL Multiphysics to accurately simulate the steady laminar flow ...
Electrostatic Screening Effects between Vertically Aligned Carbon Nanotubes and Fast Transient Joule Heating during Field Emission
M. Dionne, J.-L. Meunier, and S. Coulombe
Department of Chemical Engineering, McGill University, Montreal, QC, Canada.
To minimize the erosion of arc electrodes, surface melting must be avoided by optimizing field emission. This can be achieved through the use of sharp structures in the design of the surface topography.Carbon nanotubes standing vertically on metal substrates are good candidates for the creation of new electrodes fulfilling these requirements but their dimensions and density on the substrate must ...
S.M.F. Garcia, and P. Seshaiyer
U.S. Naval Academy, Annapolis, MD, USA
George Mason University, Fairfax, VA, USA
In this work we consider a 1-D mathematical model that describes a heating problem combined with electrical current flows in a body which may undergo a phase change as a result of the heat generated by the current, so-called Joule heating. The model consists of a system of nonlinear partial differential equations with quadratic growth in the gradient. Joule heating is generated by the resistance ...
S. Khushrushahi, A. Weddemann, Y. Kim, and M. Zahn
Massachusetts Institute of Technology
Prior work has analyzed the case of planar Poiseuille ferrofluid flows in planar ducts stressed by uniform sinusoidally applied fields transverse and perpendicular to the duct axis. The coupled linear and angular momentum conservation equations with imposed magnetic flux density, Bx and magnetic field Hz result in a fourth-order system that was numerically solved using the shooting method in ...
E. Bertarelli, R. Ardito, E. Bianchi, K. Laganà, A. Corigliano, G. Dubini, and R. Contro
Department of Structural Engineering, Politecnico di Milano, Milano, Italy
In this work, an electrostatic diaphragm micropump is investigated by means of COMSOL Multiphysics®. A fluid-dynamic model is adopted to evaluate the fluid flow characteristics inside the pumping chamber, in static conditions. In parallel, electromechanical quasi-static simulations are performed to evaluate the occurrence of membrane movement and pull-in phenomena. Finally, a simplified ...
M.H. Poech, M. Weiß, and K. Gruber
Fraunhofer Institute for Silicon Technology, Itzehoe, Germany
Since a couple of years, sintering becomes more and more important for power electronics. To press a semiconductor under high temperature in silver paste on a substrate promises benefits for durability. Tests with semiconductors of different thickness expose some problems. After the cool down, some of them fall slightly from the substrate. Stress in the boundary layer, caused by different ...
V. Thümmler1, and A. Weddemann2
1Department of Mathematics, Bielefeld University, Bielefeld, Germany
2Department of Physics, Bielefeld University, Bielefeld, Germany
Partial differential equations which exhibit solutions that are spatial temporal patterns are often found in biological and chemical systems, e.g. when describing pattern formation in reaction-diffusion systems.Special classes of such patterns are relative equilibria and relative periodic orbits, which are solutions that in an appropriately co-moving frame of reference are stationary and ...