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.

Air Damping of Oscillating MEMS Structures: Modeling and Comparison with Experiment

S. Gorelick[1], M. Leivo[1], U. Kantojärvi[1]
[1]VTT Technical Research Centre of Finland, Espoo, Finland

Excessive air damping can be detrimental to the performance of oscillating MEMS components. Complex systems, such as structures in pre-etched cavities or angular comb-drive scanning mirrors, typically require simulations to reliably evaluate the air damping. The simulated and experimental performance of the following systems was evaluated and compared: two types of out-of-plane cantilevers, ...

Numerical Study of the Controlled Droplet Breakup by Static Electric Fields inside a Microfluidic Flow-focusing Device

Y. Li[1], K. Nandakumar[1], M. Jain[1]
[1]Louisiana State Univeristy, Baton Rouge, LA, USA

Conventional passive microfluidic flow-focusing devices confront difficulties in controlling droplet sizes in dripping regime especially when the dispersed phase has a large viscosity. It is reported that external electric field can be used to manipulate the droplet breakup. In the present study, a computational fluid dynamics based level-set method coupled with perfect dielectric model has been ...

Numerical Study of Microscale Heat Sinks Using Different Shapes and Fluids

H. Garg[1], A. K. Lall[2], Nidhi[3], V. S. Negi[1]
[1]Central Scientific Instruments Organisation, Chandigarh, India
[2]PEC University of Technology, Chandigarh, India
[3]UIET, Punjab University, Chandigarh, India

Microchannel heat sinks designed for applications in electronic cooling and having microscale heat transfer combine the attributes of high material compatibility, high surface area per unit volume ratios, and large potential heat transfer performance with a highly sophisticated and economic fabrication process. The present study deals with different microchannel shapes and different properties of ...

Fluid-Structure Interaction Modeling of High-Aspect Ratio Nuclear Fuel Plates Using COMSOL Multiphysics®

F. Curtis[1], K. Ekici[1], J. D. Freels[2]
[1]The University of Tennessee, Knoxville, TN, USA
[2]Oak Ridge National Laboratory, Oak Ridge, TN, USA

The High Flux Isotope Reactor at the Oak Ridge National Lab is in the research stage of converting its fuel from high-enriched uranium to low-enriched uranium. One of the areas being explored is the fluid-structure interaction phenomenon due to the interaction of thin fuel plates (50 mils thickness) and the cooling fluid (water). Detailed computational simulations have only recently become ...

Numerical Study of the Self-ignition of Tetrafluoroethylene in a 100-dm3-reactor

F. Ferrero[1], M. Kluge[1], R. Zeps[1], T. Spoormaker[2]
[1]BAM Federal Institute for Materials Research and Testing, Berlin, Germany
[2]Chairman PlasticsEurope Fluoropolymers TFE Safety Task Force, Du Pont De Nemours, Dordrecht, The Netherlands

The self-ignition of tetrafluoroethylene (TFE) caused by contact with hot surfaces has been analyzed with the help of simulations performed with COMSOL Multiphysics®. The current study focuses on large-scale heated reactors for the industrial production of polytetrafluoroethylene (PTFE) from TFE at high pressures. Simulations of the self-heating and consequent self-ignition of TFE in a ...

Modeling of Two-Phase Flows

K. O. Lund
Engineering Consultant to SML Associates, Del Mar, CA, USA

Viscous equations are developed for regions with two interacting flowing fluids, or two fluid phases, such as occur in fluidized particle beds or the mixing of fluids. The descriptive equations are rendered into the standard COMSOL PDE matrix form, and solved over typical two-dimensional regions, as time-dependent interacting laminar flows.The model geometry selected is that of a so-called ...

Effects of Forced Airflow Cooling on Laser Beam Heating of Volume Bragg Gratings

S. Kaim[1], B. Anderson[1], G. Venus[1], J. Lumeau[1], V. Smirnov[2], B. Zeldovich[1], L. Glebov[1]
[1]CREOL, The College of Optics and Photonics, University of Central Florida, Orlando, FL, USA
[2]OptiGrate Corp, Oviedo, FL, USA

Forced airflow cooling of a Volume Bragg Grating heated by a laser beam was investigated by means of simulation with COMSOL Multiphysics®. In addition to air cooling of unrestricted airflow, a case of airflow directed by limiting glass plates was investigated. A number of temperature distributions and thermal deformations were obtained in simulations for different rates of airflows. Simulations ...

Steady and Unsteady Computational Results of Full Two Dimensional Governing Equations for Annular Internal Condensing Flows

R. Naik[1], S. Mitra[1], A. Narain[1], N. Shankar[1]
[1]Michigan Technological University, Houghton, MI, USA

This paper presents steady and unsteady computational results obtained from numerical solutions of the full two-dimensional governing equations for annular internal condensing flows in a channel. This is achieved by tracking the “sharp” interface while solving the flow fields using COMSOL Multiphysics® and MATLAB®. The unsteady wave simulation capability is used to predict heat-transfer ...

Flow Analysis and Optimization of a Hierarchical Plate Heat Exchanger for an Adsorption Heat Pump

E. Tempfli[1], F.P. Schmidt[1]
[1]Karlsruhe Institute of Technology (KIT), Fluid Machinery (FSM), Karlsruhe, Germany

The paper investigates the hydrodynamic performance of a hierarchical parallel channel network for the objective of optimal thermal coupling to heat released in the adsorption processes, as in adsorption heat pumps. More specifically, the uniformity of the fluid flow over the network is improved by optimizing the topology of the manifold channels of the two hierarchical levels. For this purpose a ...

Design of Small-Scaled de Laval Nozzle for IGLIS Experiment

E. Mogilevskiy[1], R. Ferrer[1], L. Gaffney[1], C. Granados[1], M. Huyse[1], Yu. Kudryavtsev[1], S. Raeder[1], P. Van Duppen[1]
[1]KU Leuven, Instituut voor Kern- en Stralingsfysica, Leuven, Belgium

De Laval nozzles are used in supersonic aerodynamical tubes and engines. They are also employed for the production of cold gas jets to be used in chemical reactions studies. Recently, cold gas jets have been proposed of In-Gas Laser ionization Spectroscopy (IGLIS) The nozzle has a converging and a diverging part with a throat between them. High gas pressure and temperature, and low velocity are ...

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