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
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 ...
L. Desgrosseilliers, and D. Groulx
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, H. Yin, and S. D. Felicelli
Center for Advanced Vehicular Systems, Mississippi State University, MS
Oak Ridge National Laboratory, TN
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 ...
P. Barthelemy, and
Visualization Sciences Group, Burlington, MA, USA
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 ...
M. Gobbert, and D. Trott
University of Maryland Baltimore County
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 ...
L. Graber, J. Kvitkovic, T. Chiocchio, M. Steurer, S. Pamidi, and A. Usoskin
Center for Advanced Power Systems, Florida State University, Tallahassee, FL
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 ...
J. Strong, and C. Washburn
Sandia National Laboratories
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 ...
P. Ben-Tzvi, and W. Rone
George Washington University
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 ...
A. Pandey, and N. Litchinitser
The State University of New York at Buffalo
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 ...
Modeling and Simulation of Artificial Core-Shell Based Nanodielectrics for Electrostatic Capacitors Applications
D. Musuwathi Ekanath, N. Badi, and A. Bensaoula
Center for Advanced Materials, University of Houston, Houston, TX
Dept. of Physics, University of Houston, Houston, TX
The need for high storage capacitors led to the development of polymer based capacitors. Polymers have high processability, mechanical flexibility, electrical breakdown strength and compatibility with printed circuit board (PCB) technologies; but usually have very low permittivity (K). In COMSOL Multiphysics software, the AC/DC module is selected and the In-plane electric currents are applied ...