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.

Understanding Ferrofluid Spin-Up Flows in Rotating Uniform Magnetic Fields

S. Khushrushahi, and M. Zahn
Massachusetts Institute of Technology, Cambridge, MA, USA

A fully filled sphere of ferrofluid has constant demagnetizing factors in all three Cartesian directions such that when subjected to a uniform external rotating magnetic field the internal field is also uniform, and ultrasound measurements give no observable flow. Non-uniform magnetic fields or a non-uniform distribution of susceptibility are necessary conditions for ferrofluid spin-up flows in ...

Virtual Acoustic Prototyping – Practical Applications for Loudspeaker Development

A. Salvatti
JBL Professional, Northridge, CA, USA

The author presents an overview of methods to build virtual prototypes of both horns and loudspeaker drivers which allows a significant reduction in the number of physical prototypes, as well as reduced development time. This paper will present some of the practical results from work the author has performed in the course of designing both transducers and horns using COMSOL Evolution of the ...

Characterization of an AlGaN/GaN Electrostatically Actuated Cantilever Using the Finite Element Method

N. DeRoller, M. Qazi, J. Liu, and G. Koley
University of South Carolina, Columbia, SC, USA

AlGaN/GaN heterostructures are unique because the 2DEG at the interface is created by the difference in polarization properties of the AlGaN and the GaN layers; not due to intentional doping. In this work, a 3D model of an electrostatically actuated micro cantilever has been developed using COMSOL for characterization using the finite element method (FEM). The microcantilever has AlGaN/GaN HFET ...

Simulation of a Magnetophoretic Device for the Separation of Colloidal Particles in Magnetic Fluids

S.K. Fateen, and M. Magdi
Cairo University, Giza, Egypt

Magnetophoresis of non-magnetic particles is the induced motion of non-magnetic particles suspended in magnetic media on the application of a magnetic field gradient. Magnetophoresis can be used in special separation devices to separate colloidal particles based on their sizes. Multiphysics computational programs, such as COMSOL, are ideal for the modeling and simulation of those devices. In ...

A Directional Dogbone Flextensional Sonar Transducer

S.C. Butler
Naval Undersea Warfare Center, Newport, RI, USA

In order to transmit energy in one direction, sonar flextensional transducers are combined into arrays of elements that are spaced a 1/4 wavelength apart. The directionality (front-to-back pressure ratio) is a modest of 6 dB. A single projector that is 1/3 wavelength in size and capable of developing unidirectional beams with front-to-back ratios greater than 20 dB that is independent of sound ...

Effective Medium Theory of Nanodielectrics for Embedded Energy Storage Capacitors

R. Bikky, N. Badi, and A. Bensaoula
University of Houston, Houston, TX, USA

In this work, we present the effective properties of nanodielectrics with gold (Au) nanoparticles embedded in polymer (Polyvinyl Pyrrolidone (PVP)) matrix, calculated by using finite element method (FEM) based simulation in COMSOL Multiphysics software. Drude model is used to calculate size dependent complex dielectric function of Au. EMTs of Maxwell-Garnett, Bruggeman and Looyenga models are ...

The Transient Modeling of Bubble Pinch-Off Using an ALE Moving Mesh

C.J. Forster, and M.K. Smith
Georgia Institute of Technology, Atlanta, GA, USA

The use of an acoustic field to control the boiling process has the potential to increase the overall rate of heat transfer and delay the critical transition to film boiling. This system is being investigated through the development of a model of a single boiling bubble near a flat, heated, horizontal surface in the presence of an acoustic field. The dynamics of the bubble interface is ...

Computational Modeling of Synthetic Jets

D.C. Durán, and O.D. López
Universidad de los Andes, Bogotá, Colombia

A synthetic Jet actuator is a device which moves a fluid in and outside a cavity, through a small aperture, by the continuous oscillation of a diaphragm. The multiphysics interaction between the piezoelectric disk, which deforms due to the alternating voltage, and the fluid makes COMSOL Multiphysics the most suitable tool for the computational analysis of these devices. The first approach to the ...

Modeling Horizontal Ground Heat Exchangers in Geothermal Heat Pump Systems

A. Chiasson
University of Dayton, Dayton, OH, USA

Geothermal heat pumps use the earth as a heat source and sink via a ground heat exchanger (GHX) that consists of a network of buried heat exchange pipes, which can either be installed in vertical boreholes or in shallow horizontal trenches or excavations. The main goal in GHX design is to determine the minimum length of pipe needed to provide adequate fluid temperatures to heat pumps over their ...

Electro-Thermal Analysis of a Contactor: Comparing the Performance of Two Braze Alloys during the Temperature Rise Test

E. Gutierrez-Miravete[1], and G. Contreras[2]
[1]Rensselaer at Hartford, Hartford, CT, USA
[2]General Electric Co., Plainville, CT, USA

The purpose of this study was to develop mathematical models of the coupled electro-thermal process in selected, typical contactors that could then be validated and verified by comparing model predictions with the results of previous studies and with experimental data obtained during a temperature rise test. The study employed Finite Element Analysis using COMSOL to simulate coupled electro ...