An Analysis of Heat Conduction with Change of Phase with Application to the Solidification of Copper
J. Michalski, and E. Gutirrez-Miravete
Rensselaer at Hartford, Hartford, Connecticut, US
The goal of this study was to determine the possibility of using the finite element in COMSOL Multiphysics program to obtain a high accuracy solution to a moving boundary problem, specifically, the solidification of copper. A one-dimensional geometry in Cartesian coordinates was used to investigate the solidification of initially liquid copper from a chilled wall maintained at fixed temperature. ...
Minhee Jun, and Jason V. Clark
Departments of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, USA
Large deflection actuators are becoming increasingly important for microsystems. Since actuation forces are usually small, large deflection actuators usually require flexures with low stiffness. Rectangular serpentine flexures are often used for such actuators due to their low stiffness and large linear deflection range. In this paper we investigate the performance of curved serpentine flexures ...
Z. Qin, Y. Zeng, and D.W. Shoesmith
The University of Western Ontario, London, Ontario, Canada
Models that describe hydrogen permeation through a thin TiO2 film deposited on Pd have been developed based on a mass-balance equation consisting of diffusion, reversible hydrogen absorption/desorption, and irreversible hydrogen trapping. These models are solved by the finite element method using COMSOL Multiphysics. By comparing model simulations with experimental permeation curves, values of ...
J.J. Dubowski, and D.Carrier
Department of Electrical and Computer Engineering, Université de Sherbrooke, Quebec, Canada
We present a Finite Element Method simulation procedure that allows rapid development of prototype devices comprising novel self-referenced interference SPR (surface plasmon resonance) biosensing microstructures. The procedure takes advantage of COMSOL Multiphysics and MATLAB software and their bi-directional link. The simulation is made using COMSOL RF Module, 2D harmonic propagation ...
Importance of Assembly Discontinuity Factors In Simulating Reactor Cores Containing Highly Heterogeneous Fuel Assemblies
Atomic Energy of Canada Limited, Mississuaga, Ontario, Canada
To assess the importance of assembly discontinuity factors (ADF), a highly heterogeneous reactor core was simulated using a COMSOL model in which ADF are not used. The resulting errors in assembly powers were found to be unacceptably high. This indicates that for highly heterogeneous cores such as one with MOX and LEU fuel assemblies, the use of techniques that counter the effect of ...
Department of Mechanical Engineering, University of Washington, Seattle, Washington, USA
A comparison of the commercial code COMSOL is performed with the bench-mark solutions provided by the literature for a tall, differentially heated rectangular cavity for aspect ratios of 8, 15, 20, and 33. At small Rayleigh numbers the flow is dominated by conduction. As the Rayleigh number is increased the flow becomes unstable, first resulting in multicellular secondary flow patterns, and then ...
B. L. Crossley, M. Kossler, P.J. Collins, R. A. Coutu Jr., and L. A. Starman
Air Force Institute of Technology, Wright-Patterson AFB, Ohio, USA
Carbon nanotubes (CNTs) have been proven experimentally to be well suited for field emission applications. An optimized triode configured CNT field emission array is developed using the COMSOL Multiphysics Electrostatics Application to adjust five key physical dimensions to investigate the effects on the enhanced electric field at the CNT emitter tips. The five dimensions studied are CNT ...
Marc K. Smith
Professor of Mechanical Engineering, Georgia Institute of Technology
Simple, accurate CFD simulations using COMSOL Multiphysics are used in a senior-level undergraduate course as a means to explore a number of fluid flows with the intent of developing a deep understanding of the underlying fluid mechanical mechanisms involved in the flows. Students also learn about the finite element method, how to properly pose the underlying mathematical model for the fluid ...
Boundary conditions in multiphase, porous media, transport models of thermal processes with rapid evaporation
A. Datta, and A. Halder
Biological and Environmental Engineering, Cornell University, Ithaca, New York, USA
In modeling of thermal processing of biological materials with rapid evaporation, it is critical to provide boundary conditions consistent with the phenomena happening at the surface to accurately predict spatial temperature and moisture content for quality and safety assurance. Boundary conditions in a mathematical model are as important as governing equations itself and describe how the heat ...
TM Wave Propagation in Optical Nanostructures with a Third-Order Nonlinear Response: Modeling and Validation with COMSOL
A. Kildishev, E. E. Narimanov
Birck Nanotechnology Center, School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana, USA
An enhanced method is used for analysis of third-order nonlinearities in optical nanostructures with scalar TM (H-field) frequency domain formulation. After embedding it in COMSOL Multiphysics it is shown to produce fast and accurate results without superfluous vector E-field formalism. A standard TM representation based on cubic non-linear susceptibility χ(3) results in an intractable ...