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.

The Transient Modeling of Single-Bubble Nucleate Boiling in a Sub-Cooled Liquid Using an ALE Moving Mesh

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

This paper investigates the evolution of a single bubble going through growth, pinch-off, and condensation while rising due to buoyancy forces in a sub-cooled liquid. Phase change is modeled on the evolving liquid-vapor interface by considering changes in enthalpy and heat fluxes at the interface. A comparison of the ALE model is made with the same single-bubble system computed with a level ...

Double Pipe Heat Exchanger Modelling - COMSOL Uses in Undergraduate Education

L. Desgrosseilliers, and D. Groulx
Mechanical Engineering
Dalhousie University
Halifax, NS

A cornerstone of Chemical and Mechanical Engineering undergraduate programs the world over is the experimental and theoretical study of heat exchange. Graduating engineering students gain some appreciation in their lab course by comparing empirical correlations combined with the thermodynamics of heat exchange with the real operation of a counter-current, double pipe, single-phase heat exchanger.

Simulation of Dendritic Solidification in Cubic and HCP Crystals by Cellular Automaton and Phase-Field Models

M. A. Zaeem[1], H. Yin[2], and S. D. Felicelli[3]
[1]Center for Advanced Vehicular Systems, Mississippi State University, MS
[2]Oak Ridge National Laboratory, TN
[3]Mechanical Engineering Department, Mississippi State University, MS

A cellular automaton (CA)-finite element (FE) model and a phase field (PF)-FE model were used to simulate equiaxed dendritic growth during solidification of cubic and hexagonal crystals. The governing equations of PF model include three coupled partial differential equations (PDE) for evolution of concentration, temperature, and non-conserved PF variable. These PDEs were solved using the ...

Poromechanics Investigation at Pore-scale Using Digital Rock Physics Laboratory

S. Zhang[1],
N. Saxena[2],
P. Barthelemy[1], and
M. Marsh[1]
[1]Visualization Sciences Group, Burlington, MA, USA
[2]Stanford University, Palo Alto, CA, USA

Understanding the rock structure at nano to micro scale is of growing importance in geology, oil and gas, and hydrology. New approaches that relies on a variety of high resolution 3D imaging techniques offered tremendous potential. These new approaches, in the meanwhile, introduce significant new challenges. Starting from digital imaging data, the paper introduces an image-to-simulation ...

Finite Element Convergence for Time-Dependent PDEs with a Point Source in COMSOL 4

M. Gobbert, and D. Trott
University of Maryland Baltimore County
Baltimore, MD

Many application problems have non-smooth forcing terms, such as the Dirac delta function. The convergence order for the FEM solution is limited by the regularity of the solution in this case. This paper presents information on the techniques needed in COMSOL 4 to enable FEM convergence studies for time-dependent problems of this type, including how to correctly implement the Dirac delta ...

Coupled Magnetodynamic and Electric Circuit Models for Superconducting Fault Current Limiter

L. Graber[1], J. Kvitkovic[1], T. Chiocchio[1], M. Steurer[1], S. Pamidi[1], and A. Usoskin[2]
[1]Center for Advanced Power Systems, Florida State University, Tallahassee, FL
[2]Bruker Energy & Supercon Technologies Inc., Billerica, MA

Finite element models, which include the shielding characteristics of superconductors are often complex and would currently not allow us to study 3D models of devices of complex geometry such as fault current limiters. We propose instead a model based on variable electric conductivity, which is suitable to simulate magnetic field characteristics of inductive superconducting fault current ...

Carbon MEMS Accelerometer

J. Strong, and C. Washburn
Sandia National Laboratories
Albuquerque, NM

The newly emerging field of carbon-based MEMS (C-MEMS) attempts to utilize the diverse properties of carbon to push the performance of MEMS devices beyond what is currently achievable. Our design employs a carbon-carbon composite using nano-materials to build a new class of MEMS accelerometer that is hyper-sensitive over a dynamic range from micro-G to hundreds of G’s – far surpassing the ...

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 validate ...

Study of AC Electrothermal Phenomena Models

S. Loire, and P. Kauffmann
University of California
Santa Barbara, CA

Recently, electrokinetic flows have raised the interest of the scientific community. Driving flow with an electric field leads to promising applications for mixing, concentration, pumping application in lab on chips. However, current models are still inaccurate and don\'t fit the measures. The simple decoupled model developed by Ramos et al does not predict velocities for all parameters. ...

Simulation of Field Enhancement in Anisotropic Transition Metamaterials using COMSOL

A. Pandey, and N. Litchinitser
The State University of New York at Buffalo
Buffalo, NY

Transition metamaterials constitute a new class of engineered materials which have material properties tailored in such a manner that the refractive index gradually changes from positive to negative. An important question is what happens at the interface of a positive and negative index material. In this work, we design anisotropic transition materials using metal-dielectric layers and study ...