Articles techniques et présentations

Ici vous trouverez les présentations issues des Conférences COMSOL à travers le monde. Réalisées par des utilisateurs de COMSOL Multiphysics, ces présentations explorent tous les domaines actuels d'innovation. Les applications couvrent pratiquement tous les secteurs industriels et impliquent des phénomènes électriques, mécaniques, fluidiques et chimiques. Utilisez la recherche rapide pour trouver les présentations les plus intéressantes dans votre domaine d'intérêt.

MEMS-Based Microdroplet Generation with Integrated Sensing

P. Ben-Tzvi, and W. Rone
George Washington University
Washington, DC

This paper presents model development and simulation results for a microdroplet generator capable of internally measuring the volume of dispensed droplets. The system’s integrated sensing is enabled by storing compressible gas adjacent to the dispenser’s liquid reservoir. During actuation, the net change in the compressible gas pressure is correlated to the ejected droplet volume. To ...

Xylophone Bar Magnetometry and Inertial-grade MEMS Optimisation: a Multiphysics Approach

H. T. D. Grigg, and B. J. Gallacher
Microsystems Group
Newcastle University
Newcastle upon Tyne
Tyne and Wear, UK

This paper presents ongoing research aimed at development of a MEMS magnetometer capable of nanoTesla sensitivity. Such a device would pave the way for inertial-grade MEMS IMUs. A resonant sensor is proposed, based on a Xylophone Bar sense element, and is analysed both directly and via COMSOL. Mode shapes and frequencies are found as functions of geometric parameters, and the results used ...

A Coulomb Stress Model to Simulate Induced Seismicity Due to Fluid Injection and Withdrawal in Deep Boreholes

G. Perillo[1], G. De Natale[2], C. Troise[2], A. Troiano[2], M.G. Di Giuseppe[2], A. Tramelli[2]
[1]University of Naples Parthenope, Naples, Italy
[2]INGV, Osservatorio Vesuviano, Naples, Italy

Fluid injection and withdrawal in deep wells is a basic procedure in mining activities and deep resources exploitation, i.e. oil and gas extraction, geothermal exploitation, geothermal permeability enhancement and waste ?uid disposal. All these activities have the potential to induce seismicity, as dramatically demonstrated by the 2006 Basilea earthquake of magnitude ML=3.4. The mechanism of ...

Simulation of a Magnetic Induction Method for Determining Passive Electrical Property Changes of Human Trunk Due to Vital Activities

H. Mahdavi[1], J. Rosell Ferrer[1]
[1]Universitat Politècnica de Catalunya, Barcelona, Spain

The human body consists of many different types of tissues each with specific passive electrical properties. Vital activities lead to a characteristic change of these properties and geometrical changes. Magnetic induction is a non-contact method which can be used to determine these changes. The method is based on the creation of a primary magnetic field that will produce eddy currents in the ...

Simplified Numerical Model of an Axial Impeller

A.-M. Georgescu[1], S.-C. Georgescu[2]
[1]Hydraulics and Environmental Protection Department, Technical University of Civil Engineering, Bucharest, Romania
[2]Hydraulics Department, University “Politehnica”, Bucharest, Romania

We propose a simplified numerical method to model the flow field downstream of an axial impeller. The method can be used for any axial hydraulic machinery for which, one is less interested by the flow between the blades, than by the flow field downstream of the machinery. The method is applied to an axial fan for which the pressure - flow rate curve is available. Numerical results are obtained ...

Calculations of the FMR Spectrum in 1D Magnonic Crystals

M. Mruczkiewicz[1], M. Krawczyk[1], V.K. Sakharov[2], Yu. V. Khivintsev[2], Yu. A. Filimonov[2], S. A. Nikitov[3]
[1]Nanomaterials Physics Division, Faculty of Physics, Adam Mickiewicz University, Pozna?, Poland
[2]Kotel’nikov Institute of Radio Engineering and Electronics, Russian Academy of Sciences (Saratov Branch), Saratov, Russia; Laboratory “Metamaterials”, Chernyshevsky Saratov State University, Saratov, Russia
[3]Kotel’nikov Institute of Radio Engineering and Electronics, Russian Academy of Sciences, Moscow, Russia; Laboratory “Metamaterials”, Chernyshevsky Saratov State University, Saratov, Russia

FMR spectra of the periodic microstructures (one-dimensional magnonic crystals, 1D MCs) were obtained using COMSOL with use partial differential equation interface. Results of these calculations were successfully compared with an experimental data for Damon-Eshbach (DE) and Backward-Volume (BV) geometries. The presented tool allows to analyze periodic structures with various geometries and ...

Elasto-Plastic FEM Models Explain the Emplacement of Shallow Magma Intrusions in Volcanic Complexes

A. Bistacchi[1]
[1]Università degli Studi di Milano Bicocca, Milano, Italy

We present numerical models and field data that aid understanding of volcano-tectonic processes related to the propagation of inclined sheets and dykes under a stress field resulting from the inflation of a shallow magma chamber. Structural field data from the classical Cuillins cone-sheet complex (Isle of Skye) show that sheets have a constant average dip angle (45°), with pure dilational or ...

Assessment of Anterior Spinal Artery Blood Flow following Spinal Cord Injury

M. Alshareef[1], A. Alshareef[2], V. Krishna[3], M. Kindy[3], T. Shazly[4]
[1]College of Medicine, Medical University of South Carolina, Charleston, SC, USA
[2]Department of Biomedical Engineering, Duke University, Durham, NC, USA
[3]Department of Neurosurgery, Medical University of South Carolina, Charleston, SC, USA
[4]Department of Mechanical Engineering, University of South Carolina, Columbia, SC, USA

The incidence of spinal cord injury (SCI) in the US is approximately 12,000 individuals annually, due to various forms of trauma and disease. Diminished flow over a prolonged period of time can cause permanent spinal damage. We constructed a 3D finite element model of the spinal cord to examine the role of compressive loading on spinal blood flow. It was found that the type of forces on the ...

Using COMSOL to Estimate the Heat Losses of Composite Panels Undergoing Repairs Using Bayesian Inference

A. Emery[1]
[1]University of Washington, Seattle, WA, USA

Composite repairs involve applying a prescribed heat flux which must be adjusted to account for heat losses. These losses must be estimated. Parameter estimation requires a knowledge of sensitivities. This is often done using finite differences. As shown in the figure, substantial errors often occur. The paper describes the use of the PDE features of COMSOL to obtain much more accurate values by ...

Low Pt Cathodes for High Performance PEMFCs: Modeling and Experiments

F. Daouda[1], J. Hamelin[1], P. Benard[1], S. Kumar Natarajan [1]
[1]Insitut de recherche sur l'hydrogène, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada

We present a novel multi-layered electrode fabrication technique for polymer electrolyte membrane fuel cells (PEMFCs). This method consists of alternate layers of Pt deposition (0.05 mg/cm²) by sputtering on the painted multi-walled carbon-Nafion layer (CNL) with larger concentration of catalyst particles closer to the membrane. Parametric models were developed and validated by experimental ...

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