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.

Heat and Mass Transfer in a Gypsum Board Subjected to Fire

B. Weber
Swiss Federal Laboratories for Materials Science and Technology
Duebendorf, Switzerland

Heat and mass transfer through a gypsum board exposed to fire is simulated and compared to experimental data. The gypsum board is modeled as a porous medium with moist air in the pores. A dehydration front develops at the fire side and travels through the board, consuming energy and releasing water vapor. The vapor migrates through the porous medium by convection and diffusion, and condenses in ...

A Wide Range MEMS Vacuum Gauge Based on Knudsen’s Forces

V. Sista, and E. Bhattarchaya
Microelectronics and MEMS Lab
Department of Electrical Engineering
Indian Institute of technology Madras
Chennai, India

A MEMS based Knudsen’s pressure gauge working in the range of 1e-5 mbar to 10 mbar is designed and simulated in COMSOL. The working principle is based on Knudsen’s forces that arise when two plates are held at different temperatures and their separation is comparable to the mean free path of the ambient gas molecules. The forces change the separation between the plates and capacitance between ...

Planar Geometry Ferrofluid Flows in Spatially Uniform Sinusoidally Time-Varying Magnetic Fields

S. Khushrushahi, A. Weddemann, Y. Kim, and M. Zahn
Massachusetts Institute of Technology
Cambridge, MA

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 ...

Impact Assessment of Hydrologic and Operational Factors on the Efficiency of Managed Aquifer Recharge Scheme

M.A. Rahman[1], P. Oberdorfer[1], Y. Jin[1], M. Pervin[1], E. Holzbecher[1]
[1]Department of Applied Geology, Geoscience Center, University of Göttingen, Göttingen, Lower Saxony, Germany

Due to increased demands on groundwater accompanied by increased drawdowns (ca. 2-3 meters/year), technologies that use alternative water resources have been suggested for Dhaka City, Bangladesh. Preliminary studies show that managed aquifer recharge (MAR) would help in optimal use of available water resources and to reduce adverse effects of pumping in the Dupitila aquifer of the city. In this ...

Capacitive Accelerometer Characteristics Study

B. S. Kavitha[1], S. B. Rudraswamy[1], C. R. Venugopal[1]
[1]SJCE, Mysore, Karnataka, India

This paper will describe the dependence of capacitive accelerometer characteristics on the accelerometers physical dimension and its material properties. The sense element of the accelerometer is designed on the basis of a commercially available torsion based accelerometer technology. The sense element consists of an asymmetrically shaped flat plate of metal supported above a substrate surface ...

Design and Simulation of MEMS Based Piezoelectric Vibration Energy Harvesting System

M. C. B. Kumar[1], D. B. Prabhu[1], R. Akila[1], A. Gupta[1], M. Alagappan[1]
[1]PSG College of Technology, Coimbatore, Tamil nadu, India

This paper discusses the simulation studies on a vibration based energy harvesting system to convert the undesirable mechanical vibration to useful green power. The design consists of a resonating proof mass and a spring system enclosed in housing and fixed on the source of vibration. A piezoelectric suspension acts as the transducer and generates a voltage that is used to charge the batteries ...

Numerical Calculation of the Dynamic Behavior of Asynchronous Motors with COMSOL Multiphysics

J. Güdelhöfer[1], R. Gottkehaskamp[1], A. Hartmann[1]
[1]Department of Electrical Machines and Electromagnetic Field Theory, University of Applied Sciences Düsseldorf, Düsseldorf, Germany

This paper shows how a time-dependent and non-linear simulation of the dynamic operation behavior of an induction machine is executed by means of the \"Rotating Machinery\" interface from COMSOL Multiphysics 4.2a. The two-dimensional FEM model is connected to electrical circuits by coupling the physics \"Rotating Machinery\" and \"Electrical Circuit\" interfaces. These circuits include the ...

Simulation of Heat Transfer on Periodic Microstructured Surfaces for Evaporation Cooling

M. Hackert-Oschätzchen[1], R. Paul[1], M. Penzel[1], M. Zinecker[1], A. Schubert[1]
[1]Professorship Micromanufacturing Technology, Technische Universität Chemnitz, Chemnitz, Germany

Evaporative cooling is a promising cooling method for dissipating high heat fluxes in high power density applications. One possibility to enhance heat flux is a generation of microstructures into the cooler surface. This enlarges the cooler surface and systematically affects the fluid flow as well as the boiling process. In this study the geometric arrangement of cylindrical pin microstructures ...

Elucidating the Mechanism Governing the Cell Rotation Behavior Under DEP

G. Zhang[1], Y. Zhao[1], J. Brcka[2], J. Faguet[2], E. Lee[2]
[1]Clemson University, Clemson, SC, USA
[2]TEL U.S. Holdings, Inc., U.S. Technology Development Center, Austin, TX, USA

In our experiments with manipulating cells with DEP, we noted that some cells are constantly spining. By hypothesing that the cell spining is caused by the non-circular shape of the cell body and the off-centered location of its nucleus and that the rotation direction depends on the relative location of nucleus with respect to the electrical field, we found that the observed cell rotation was ...

Development of a Multiphase, Multispecies Droplet Evaporation Model for Optimization of Desiccation Preservation Techniques

A. Sinkevich[1], S. Bhowmick [1], M. Raessi[1]
[1]University of Massachusetts Dartmouth, North Dartmouth, MA, USA

Biopreservation deals with the protection and storage of complex biologics such as proteins, lipids, and recently, mammalian cells. One preservation method, known as lyopreservation, involves placing a biologic inside a water droplet with some type of sugar excipient (sucrose, trehalose, etc.) and drying the solution convectively. We are currently developing a model that couples the two-phase ...