M. Herring Jensen
Widex A/S, Vaerloese, Denmark
In this study we model the sound attenuation properties of a hearing aid earmold tube. The model includes thermoviscous acoustic effects and it couples structural vibrations to the external acoustic field. Moreover, the finite element domain is coupled at two boundaries with an electroacoustic model of a hearing aid and an acoustic 2-cc coupler.
Two-dimensional Analysis of Triple Coupled Physics of Structural Mechanics, Diffusion and Heat Transfer in a Gas Pipe
P. Lee-Sullivan, and M. Haghighi-Yazdi
Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, Ontario, Canada
In this study, a 2-D model has been built using COMSOL Multiphysics® to analyze a triple coupled physics problem involving simultaneous gas diffusion, heat transfer, and structural mechanics in a pipe due to the flow of high-pressure carbon dioxide. The problem geometry and boundary conditions were based on the analysis by Rambert et al. who have published the most advanced modeling work in ...
COMSOL Multiphysics for Efficient Solution of a Transient Reaction-Diffusion System with Fast Reaction
M.K. Gobbert, A. Churchill, G. Wang, and T.I. Seidman
Department of Mathematics and Statistics, University of Maryland, Baltimore County, Baltimore, Maryland, USA
A reaction between chemical species is modeled by a particular reaction pathway, in which one reaction is very fast relative to the other one. The diffusion controlled reactions of these species together with a reaction intermediate are described by a system of three transient reaction diffusion equations over a two-dimensional spatial domain. In the asymptotic limit of the reaction parameter ...
Effect of Antennae Polarization Relative to Tunnel Orientation on Electromagnetic Wave Scattering due to Underground Tunnels
A. Farid, and T. Raza
Civil Engineering, Boise State University, Boise, Idaho, USA
Illegal immigrants and smugglers frequently use underground tunnels to avoid border security and checkpoints. In addition, the threat of international terrorism has recently made the effort to detect tunnels a national security priority. No single technology and sensing modality is capable of detecting tunnels in all heterogeneous soils environments. The goal of this research is to study and ...
Image-Based Simulation of Electrical Impedance Techniques Applied on the Human Thorax for Cardio-Pulmonary Applications
F.K. Hermans, R.M. Heethaar, R.T. Cotton, and A. Harkara
VU University Medical Center, Amsterdam, The Netherlands
Simpleware Ltd., Exeter, United Kingdom
For medical diagnostic purposes there is an increasing need for non- (or minimal) invasive techniques to measure all kinds of parameters that can provide insight in the functioning of cells, organs or organ systems. Currently, Impedance Cardiography (ICG) is used for measurements of the heart and Electric Impedance Tomography (EIT) is used for investigating lung tissue condition. This paper ...
H.H. Chen-Mayer, and R. Tosh
Ionizing Radiation Division, National Institute of Standards and Technology, Gaithersburg, Maryland, USA
Water calorimetry is employed to establish a primary reference standard for radiation dosimetry by measuring the temperature rises in a water phantom (a cube of about 30 cm x 30 cm x 30 cm) subjected to a beam of ionizing radiation. We use COMSOL Multiphysics to model the system using the Heat Transfer module and the Incompressible Navier-Stokes module with a geometry of 2D-axial ...
A-G. Ghiaus, M-A. Istrate, and A-M. Georgescu
Technical University of Civil Egineering, Bucharest, Romania
Analysis and optimization of air flow distribution inside drying kiln systems contribute to the improvement of the final product quality. The present study reports on the threedimensional numerical solution of air flow within a drying kiln enclosure. The air flow field is examined in different configurations and operation conditions. Depending on the off/on switched fans, we obtain various air ...
Z. Fang[1,2], R. O'Handley, Y. Liu, and M. Yang[2,3]
Pennsylvania State University, University Park, PA, USA
Ferro Solutions Inc., Woburn, MA, USA
Massachusetts Institute of Technology, Cambridge, MA, USA
Here we investigate a promising passive cooling method through making advantage of the unique properties of ferrofluid. When a magnetic dipole or a permanent magnet is put at the hot side of a system, it will attract the cold ferrofluid to the hot place and displace the hot ferrofluid since cold ferrofluid below Tc has much stronger magnetization than that of hot ferrofluid above Tc. Then the ...
China Electronics Technology Group Corporation, China
With this presentation, some content has been discussed from several parts as follows: 1. Plasma switches are introduced by their derivation and types, and the operating mechanism of Hydrogen cross field plasma switch is indicated then. 2. The related theories of Hydrogen plasma to simulate a DC discharge have been discussed. 3. Hydrogen simulation model is established from two aspects: A: Fixed ...
E. Evgin, J. Infante Sedano, and Z. Fu
University of Ottawa
This paper is a part of a study on energy piles for heating and cooling of buildings. Energy piles are used for two reasons: (1) to transfer structural loads to foundation soils, and (2) to transfer heat from foundation soils to the building for space heating in winter time and for cooling purposes in summer time by transferring heat from the building to the foundation soils. The efficiency of ...