K. O. Lund
Engineering Consultant to SML Associates, Del Mar, CA, USA
Viscous equations are developed for regions with two interacting flowing fluids, or two fluid phases, such as occur in fluidized particle beds or the mixing of fluids. The descriptive equations are rendered into the standard COMSOL PDE matrix form, and solved over typical two-dimensional regions, as time-dependent interacting laminar flows.The model geometry selected is that of a so-called ...
A Finite Element Analysis of the Influence of Morphology on Barrier Properties of Polymer-Clay Nanocomposites
D. L. Statler Jr., and R. K. Gupta
Department of Chemical Engineering, West Virginia University, Morgantown, WV, USA
Nanocomposites, formed by dispersing a few weight-percent of nanometer-thick platelets of organically-coated montmorillonite clay in a variety of polymers, are being used in food packaging applications. The clay platelets reduce the diffusion coefficient of gases, such as carbon dioxide and water vapor, and prolong the shelf-life of packaged foods and carbonated beverages. Here we use the COMSOL ...
Compensating Spatial Variability of Quantity Index in 2D Electrical Impedance Tomography: COMSOL Multiphysics Study
S. Oh, and R. Sadleir
Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
In Electrical Impedance Tomography (EIT), an array of surface electrodes is used to inject current and measure the resulting voltages to non-invasively obtain conductivity distributions of objects. The system can be easily implemented as a device that monitors hemorrhage, respiration, gastric emptying or brain activities.The Quantity Index (QI), an integral measure of reconstructed images, can be ...
H. Esfandyarpour1,2, A. Maiyegun1, and R. W. Davis2
1Center for Integrated Systems, Department of Electrical Engineering, Stanford University, Stanford, CA, USA
2Stanford Genome Technology Center, Stanford, CA, USA
We present a preliminary investigation of a Nanoneedle biosensor as an ultra sensitive and localized impedance biosensor using COMSOL.This preliminary study was performed to prove the feasibility of the impedance biosensor for detection of protein or nucleic acids. By monitoring the change in capacitance and impedance of this structure, we aim to characterize and classify biological species such ...
M. Crosskey and E. Gutierrez-Miravete
Department of Engineering and Science, Rensselaer at Hartford, Hartford, CT, USA
COMSOL Multiphysics has been used to model the temperature distribution produced inside a tool as a result of the forces and friction involved in a cutting process, along with the resulting diffusional flow of cobalt binder from the tool.The model uses as the input tool rake and flank face temperatures determined either experimentally or from other models, and then proceeds to couple the thermal ...
I. Ponomarev 1, M. Bayer2, and T. Reinecke1
1Naval Research Laboratory, Washington, DC, USA
2Universität Dortmund, Dortmund, Germany
The influence of disorder on the optical mode spectrum of chains of coupled micron-sized microcavities has been studied both experimentally and theoretically with the help of COMSOL. The disorder is introduced by systematic variation of cavity sizes. The resulting spectra are interpreted in terms of modified dispersion for propagation along the chains accompanied by the appearance of localized ...
V. Mathur1, J. Li1, J. Therrien2, and W. D. Goodhue1
1Photonics Center, Department of Physics and Applied Physics, University of Massachusetts, Lowell, MA, USA
2Department of Electrical Engineering, University of Massachusetts, Lowell, MA, USA
Several methods have been demonstrated for depositing nanotubes on microstructures, ranging from using an atomic force microscope (AFM) tip for single tube manipulation to chemically pre-patterning the substrate. However, these techniques have a very low yield and poor reproducibility. Sorting techniques involving filtration and ultrasonication face similar issues. Recently, electric field ...
B. A. Finlayson
Department of Chemical Engineering, University of Washington, Seattle, WA, USA
COMSOL Multiphysics is used to solve the problem of a ferrofluid placed in a rotating magnetic field, known as the spin-up problem. The spin-up phenomenon occurs when the fluid is contained in a cylinder and a homogeneous magnetic field rotates uniformly in the circular cross-section.This work shows how to implement the pertinent equations in COMSOL Multiphysics and shows that the simulations ...
Acoustic Transparency of Non-homogeneous Plates (with repeating inclusions) using Periodic Structures Methodology
A. J. Kalinowski
Naval Undersea Warfare Center/Div. Npt. Newport, RI, USA
The paper addresses a class of problems for determining the acoustic interaction of time-harmonic plane waves impinging upon submerged elastic plates (fluid backed or void backed), that are infinite in extent.The plates can have repeated equally spaced inclusions (voids, solids, ribs etc.), and also can be constructed from orthotropic and/or isotropic layers that can have a frequency dependent ...
W. R. Schlichting1, R. T. Lahey Jr.1, M. Z. Podowski1, and T. A. Ortega G?mez2
1Center for Mutliphase Research, Rensselaer Polytechnic Institute, Troy, NY, USA
2Institute for Nuclear & Energy Technologies, Karlsruhe Institute of Technology, Karlsruhe, Germany
Boiling systems must be analyzed to determine their stability characteristics. Multiphase system instabilities can be predicted by the use of a one-dimensional drift-flux model. Using this model, an analysis has been performed with the COMSOL code to investigate both linear and nonlinear instability phenomena. In particular, density-wave oscillations in boiling channels were investigated, and, ...