Aqui você encontrará apresentações realizadas nas Conferências de Usuários COMSOL de todo o mundo. As apresentações englobam pesquisas e produtos inovadores feitas por engenheiros e cientistas usando o COMSOL Multiphysics. Os tópicos abrangem uma grande gama de indústrias e aplicações, como elétrica, mecânica, escoamento e química. Use a função de busca "Quick Search" para encontrar apresentações na sua área de interesse.

An Analysis of Skimboard Hydrodynamics

N.D. Barnett[1], and E. Gutirrez-Miravete[2]
[1]General Dynamics-Electric Boat, Kingston, Rhode Island, USA
[2]Rensselaer at Hartford, Hartford, Connecticut, USA

This paper report on a study of the hydrodynamics of skimboards and surfboards using the computational fluid dynamics (CFD) module in COMSOL. The study analyzes the flow in a thin water layer underneath a skim board in a 2-D Cartesian coordinate. Three different sets of boundary conditions were employed and one of them produced the best agreement with previous findings.

Simulating the Influence of the Nozzle Diameter on the Shape of Micro Geometries Generated with Jet Electrochemical Machining

A. Schubert[1][2], M. Hackert[1], and G. Meichsner[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 for micromachining. Based on localized anodic dissolution three-dimensional geometries and microstructured surfaces can be manufactured using Jet-ECM. COMSOL Multiphysics is used at Chemnitz UT to simulate the electric current density in the jet and the dissolution process. A mesh displacement dependent on the normal current ...

Estimation of Boundary Properties Using Stochastic Differential Equations and COMSOL

A. Atalla[1], and A. Jeremic[1]
[1]McMaster University, Hamilton, Ontario, Canada

The inverse diffusion problems deal with the estimation of many crucial parameters such as the diffusion coefficient, source properties, and boundary conditions. Such algorithms are widely applied in many design problems in different physical, chemical, and biological fields. Recently, the estimation of the boundary properties, of the diffusion process, have attracted researchers. We first ...

Earthquake and Volcano Clustering at Mono Basin (California)

D. La Marra[1], A. Manconi[2], and M. Battaglia[1]
[1]Dept of Earth Sciences, University of Rome “La Sapienza”, Roma, Italy
[2]IRPI-CNR, Strada delle Cacce, Torino, Italy

This study investigates the feedback between fault slip and dike intrusions during the Mono-Inyo eruption sequence of ~1350 A.D. (Mono Basin, California). We perform an extensive validation of 3D finite element models, implemented in the Structural Mechanics module of COMSOL Multiphysics, against standard analytical solutions of fault dislocation in a homogeneous elastic flat halfspace. The ...

Convergence Rates For Models With Coupled 1D / 2D Subdomains

A. Bradji[1], E. Holzbecher[2], and M.S. Litz[2]
[1]Department of Mathematics, University of Annaba, Algeria
[2]Georg-August Universität Göttingen, Germany

It is well known that the convergence rate of a numerical model is significantly reduced, when the genuine character of the setting with differential equation and boundary condition is not given anymore. Here we examine the decrease of convergence order for models using COMSOL in which the problem set-up includes a coupling between a 1D and a 2D subdomain. In terms of physics we are dealing with ...

Comparison of Computational Methods for the Estimation of the Dielectrophoretic Force Acting on Biological Cells and Aggregates in Silicon Lab-on-chip

S. Burgarella[1], F. Maggioni[2], and G. Naldi[2]
[1]STMicroelectronics, Agrate Brianza, Milan, Italy
[2]Department of Mathematics, University of Milan, Milan, Italy

Dielectrophoresis is a method for cell manipulation in miniaturized devices exploiting the dielectric properties of cells and/or cellular aggregates suspended in a fluid and subjected to a high-gradient electric field. The mathematical expression of the force is obtained by a multipole expansion whose terms involve increasing power of the particle\'s radius. Three methods for the expression ...

Electro-acoustic Coupling in Nematic Liquid Crystals

G. Rosi[1], L. Teresi[1], A. DiCarlo[1], and F. dell'Isola[2]
[1]LaMS - Università degli Studi Roma Tre, Roma, Italy
[2]Università degli Studi di Roma "La Sapienza", Roma, Italy

Liquid crystals - as all liquids - are generally modelled as incompressible media. In fact, mass-density changes occurring in these mesophases are minuscule and inconsequential in most regimes of interest. However, liquid crystals exhibit also phenomena that call for a more refined theory. In particular, it is experimentally well established that the Fréedericksz transition - i.e., the sudden ...

Analysis & Design Optimization of Laterally Driven PolySilicon Electro-thermal Microgripper for Micro-objects Manipulation

T. Pahwa[1], S. Gupta[1], V. Bansal[1], R. Narwal[1], B. Prasad[1], D. Kumar[1]
[1]Electronic Science Department, Kurukshetra University, Kurukshetra, India

Micro-grippers find applications in micro-robotics, microsurgery, micro-fluidics, micro-relays, assembling and miniature medical instrumentation. Actuation principle involved may be electrothermal, electrostatic, piezoelectric, shape memory and electromagnetic. It has been found that thermal actuation provides greater displacement at low voltages when compared to other mechanisms. A 3-D ...

Investigation of the Effect of Spinal Defects on Spondylolysis and Stress Fracture of Vertebral Bodies

M.S. Yeoman[1], C. Quah[2], A. Cizinauskas[1], K. Cooper[1], D. McNally[5], B. Boszczyk[2]
[1]Continuum Blue, Tredomen, Ystrad Mynach, United Kingdom
[2]The Centre for Spinal Studies and Surgery, Queen’s Medical Centre, Nottingham, United Kingdom
[5]Bioengineering Research Group, Faculty of Engineering, The University of Nottingham, Nottingham, United Kingdom

Spondylolysis (SL) is a defect of the spinal vertebra, and is typically caused by stress fracture of the pars interarticularis bone of the vertebral arch. It is especially common in adolescents who over train in sporting activities. Spina bifida occulta (SBO) is a malformation of the spine where the protruding vertebral bodies are not fully formed. In this study we demonstrate the predisposition ...

Simulation, Fabrication and Observation of Plasmonic Halos

F. Ye[1], M. Burns[1], J. Merlo[1], M. Naughton[1]
[1]Department of Physics, Boston College, Chestnut Hill, MA, USA

We present the simulation, observation and systematic study of a novel optical phenomenon, a “plasmonic halo”, wherein optically pumped surface plasmons on circular silver microcavities form confined drumhead modes that, under off-resonant conditions, transform to colorful far field radiation at their circumferential boundaries. We simulated the surface plasmon drumhead modes via COMSOL ...