Technical Papers and Presentations

Here you will find presentations given at COMSOL Conferences around the globe. The presentations explore the innovative research and products designed by your peers using COMSOL Multiphysics. Research topics span a wide array of industries and application areas, including the electrical, mechanical, fluid, and chemical disciplines. Use the Quick Search to find presentations pertaining to your application area.

FEM Correlation and Shock Analysis of a VNC MEMS Mirror Segment

E. Aguayo[1], R. Lyon[2], M. Helmbrecht[3], S. Khomusi[1]
[1]The Newton Corporation, Bowie, MD, USA
[2]NASA Goddard Space Flight Center, Greenbelt, MD, USA
[3]Iris AO, Inc., Berkeley, CA, USA

Microelectromechanical systems (MEMS) are becoming more prevalent in today’s space technologies. The Visible Nulling Coronagraph (VNC) instrument, being developed at the NASA Goddard Space Flight Center, uses a MEMS Mirror to correct wavefront errors. This MEMS, the Multiple Mirror Array (MMA), will enable the VNC instrument to detect Jupiter and ultimately Earth size exoplanets. The MMA ...

Structural Optimization of the AISHa Ion Source

F. Noto[1], M. Piscopo[1], L. Celona[1], D. Cittadino[1], S. Gammino[1], G. Cuttone[1], G. Gallo[1], G. Schillaci[1], C. Campisano[2], L. Lo Nigro[3], G. Costa[3], A. Campisano[4]
[1]Laboratorio Nazionale del Sud, Santa Sofia, Catania, Italy
[2]Gravina di Catania, Sicily, Italy
[3]Trinacria, Canalicchio, Catania, Italy
[4]Unico Informatica, li Battiati, Catania, Italy

Different facilities for hadrontherapy have been built in the recent past. AISHa ion source has been designed by keeping in mind the typical requirements of hospital-based facilities, where the minimization of the mean time between failures (MTBF) is a key point together with the maintenance operations which should be fast and easy. The study of some critical parts of the facilities: the ...

Modeling of Expanding Metal Foams

B. Chinè[1,2], M. Monno[3]
[1]Laboratorio MUSP, Macchine Utensili e Sistemi di Produzione, Piacenza, Italy
[2]School of Materials Science and Engineering, Costa Rica Institute of Technology, Cartago, Costa Rica
[3]Politecnico di Milano, Dipartimento di Meccanica, Milano, Italy

Metal foams are interesting materials with many potential applications. They are characterized by a cellular structure represented by a metal or metal alloy and gas voids inside (Fig.1). A common metallic cellular material is aluminum foam which can be produced metallurgically by heating a precursor, made of aluminum alloy and TiH2 as foaming agent, in a furnace. In this case, the foaming process ...

A Phase Field Approach to Model Laser Power Control in Spot Laser Welding

C. Touvrey[1], V. Bruyere[2], P. Namy[2]
[1]CEA DAM, Valduc, France
[2]SIMTEC, Grenoble, France

Spot laser welding is largely used in industrial manufacturing, especially in the case of small penetration depth. Unfortunately, welded joins are often polluted by porosities. The formation of porosities depends on complex thermo-hydraulic phenomena. During the interaction, a deep and narrow cavity - called the keyhole - is formed. At the end of the interaction, surface tension forces ...

Thermal Field in a NMR Cryostat

A. D'Orazio[1], C. Agostini[1], S. Fiacco[1]
[1]Dipartimento di Ingegneria Astronautica, Elettrica ed Energetica - Sapienza University of Rome, Rome, Italy

Fundamental component of the NMR tomograph is the magnet. By using the property of superconductivity it is possible to achieve an induction field extremely homogeneous, stable and high. To maintain the material below the superconducting critical temperature (7.2K), the coils are immersed in liquid helium at 4K, within a cryostat. In this paper, we present the preliminary results related to the ...

Simple Finite Element Model of the Topografiner

H. Cabrera[1], D. A. Zanin[1], L. G. De Pietro[1], A. Vindigni[1], U. Ramsperger[1], D. Pescia[1]
[1]Laboratory for Solid State Physics, ETH Zürich, Zürich, Switzerland

In our recent experiments we are revisiting the topografiner technology for the imaging of surface topography with a resolution of a few nanometers. In these new technique called Near-Field Emission Scanning Electron Microscopy (NFESEM), low-energy electrons are emitted from a polycrystalline tungsten tip via electric-field assisted tunneling. In order to characterize and improve the capabilities ...

Simple Disk Piezo Transformer Based Oscillator

J. P. Sandoz[1], J. M. Kissling[1]
[1]Institute of Applied Microtechnology, La Chaux-de-Fonds, HE‐ARC, Switzerland

In this contribution we present a COMSOL Multiphysics® example of a disk piezoelectric ceramic transformer (D-PT) coupled with a bipolar NPN transistor to form an auto-oscillator. The comparison between the simulations and the measurements made on our prototype are found to be in good agreement. Having at our disposal a large number of homogenously poled disks, we decided to build and to ...

Prediction of Air Permeability Using a Finite Element Method

A. Pezzin[1], A. Ferri[1]
[1]Politecnico di Torino, Torino, Italy

Air permeability is one of the most important parameters in the study of thermo-physiological comfort of fabrics. The main goal of this work is to develop a virtual process that allows the prediction of air permeability of any fabric without realizing a sample. The Free and Porous Media Flow physics interface was used in COMSOL Multiphysics® software; this allows to use Navier-Stokes equation ...

Numerical Simulation of Chamber Design for Pulsed Electric Fields Processing of Wet Olive Pomace

N. Varga[1], I. Perales[2], A. Portugal[2]
[1]ATEKNEA Solutions Hungary, Budapest, Hungary
[2]ATEKNEA Solutions Catalonia, Barcelona, Spain

The application of pulsed electric fields (PEF) is well known in the food industry as an advanced technology for mass transfer improvement. A new potential adaptation area of PEF could be extracting a valuable antioxidant called polyphenol from wet olive pomace (WOP) which is a by-product of olive oil production. The modelling includes the PEF effects on the WOP which is flowing through a ...

Generalized Plane Piezoelectric Problem: Application to Heterostructure Nanowires

H. T. Mengistu[1], A. García-Cristóbal[1]
[1]Material Science Institute, University of Valencia, Valencia, Spain

The possibility to dispose of two-dimensional (2D) approaches to problems originally posed in a three-dimensional (3D) geometry is always desirable since it reduces significantly the computing resources needed for numerical studies. In this work we report on a new 2D approach called Generalized Plane Piezoelectric (GPP) problem [1] and apply it to the calculation of the strain and electric fields ...

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