I. Terechkine, T. Khabiboulline, D. Sergatskov
Fermi National Accelerator Laboratory, Batavia, IL, USA
Performance degradation of a superconducting RF cavity after quenching in an external magnetic field was calculated using COMSOL. This degradation is due to the increased resistance of a superconducting surface with trapped magnetic flux. The amount of the trapped flux depends on the size of the normally-conducting opening that develops in the superconducting wall of a cavity during quenching. ...
Modeling and Analysis of a Direct Expansion Geothermal Heat Pump (DX): Part I-Modeling of Ground Heat Exchanger
C. Rousseau, J. Fannou, L. Lamarche, M. Ouzzane
École de Technologie Supérieure, Montréal, Québec, Canada
CanmetENERGY, Varennes, Québec, Canada
Geothermal heat pump technology is actually one of the most interesting processes to provide heat and cold to a building. In this study, a model of the ground exchanger of a direct expansion geothermal heat pump (DX) is going to be presented in 1 dimension. The model represents the phase change of the refrigerant, here Chlorodifluoromethane R22, with governing continuity, momentum and energy ...
A. Aman, R. Gentile, Y. Chen, X. Huang, Y. Xu, N. Orlovskaya
Department of Mechanical, Materials and Aerospace Engineering, University of Central Florida, Orlando, FL, USA
Department of Mechanical Engineering, University of South Carolina, Columbia, SC, USA
Solid oxide fuel cells (SOFCs) are electrochemical conversion devices that utilize ceramics as their electrolyte material for oxygen conduction. Compared to other types of fuel cells, they operate at relatively high temperatures, typically 400°C to 1000°C, and have an electrical efficiency over 50% and combined heat and power efficiency over 80%. One way to improve cell performance is to use ...
Modeling and Analysis of a Direct Geothermal Heat Pump (DX): Part II-Modeling of Water-Refrigerant Exchanger
J. Fannou, C. Rouseau, L. Lamarche, S. Kajl
École de Technologie Supérieure, Montréal, Canada
In this section, we simulate the heat exchanger system in one dimension characterized by two coaxial tubes with ribbed inner tube using the equations of conservation of mass, conservation of momentum and energy. The COMSOL PDE interface is used to simulate the monophasic and biphasic flow of refrigerant R22 (Chlorodifluoromethane). Heat transfer in waterand inner wall of the exchanger are ...
E. Gkanas, S. Makridis, E. Kikkinides, A. Stubos
Department of Mechanical Engineering, University of Western Macedonia, Kozani, Greece
Environmental Laboratory, Institute of Nuclear Technology and Radiation Protection, NCSR 'Demokritos', Agia Paraskevi, Athens, Greece
Hydrogen storage in a metal hydride bed, uses an intermetallic alloy that can absorb efficiently high amounts of hydrogen by chemical bonding resulting to metal hydrides. This alloy is capable of absorbing and desorbing hydrogen while maintaining its own structure. The heat, mass and momentum transfer in a metal-hydride reactor is mathematically described by energy, mass and momentum balance ...
A. Czirják, Z. Kőkuti, G. Tóth-Molnár, P. Ailer, L. Palkovics, G. Szabó
University of Szeged, Szeged, Hungary
Kecskemét College, Kecskemét, Hungary
In certain cases, the accuracy of measurements with a rotational rheometer can be influenced by inefficient thermal management, by the heat generated in the sample, or by rod-climbing due to the Weissenberg effect. We investigate the effect of these phenomena with simulations in COMSOL Multiphysics®. Our model is based on the axial symmetric (2D) formulation of the two-phase flow with the ...
M. J. Hancock, N. H. Elabbasi, M. C. Demirel
Veryst Engineering, LLC., Needham, MA, USA
Pennsylvania State University, University Park, PA, USA
Pumping liquids at small scales is challenging because of the principle of reversibility: in a viscous regime, the flow streamlines through a fixed geometry are the same regardless of flow direction. Recently we developed a class of microfluidic pump designs based on tilted flexible structures that combines the concepts of cilia (flexible elastic elements) and rectifiers (e.g., Tesla pump). We ...
A. Gil-Garcia, I. Kings, B. Al-Duri
University of Birmingham, School of Chemical Engineering, Edgbaston, Birmingham, UK
In clean coal technologies, improving energy conversion efficiency is one of the most important directions. Compared to traditional subcritical power plants, pressure-increased supercritical power plants improve the plant energy efficiency from 35% up to 45%. This work presents a study of the thermodynamic behaviour of the water cycle in coal-fired boilers in response to the changes in energy ...
L. Wright, G. Memoli, P. Jones, E. Stride
National Physical Laboratory, Teddington, UK
University College London, London, UK
University of Oxford, Oxford, UK
Understanding the interactions between microbubbles and surfaces is key to the successful deployment of microbubbles in a range of applications. Two important examples are their use as a drug delivery mechanism, and their potential use of acoustically-driven bubbles as microscale sensors. Drug delivery with bubbles involves sonication at high frequency close to a boundary, and sensing with ...
M. A. Chetoui , O. Boiron , A. Dogui , V. Deplano ,
 Université de Monastir, Ecole Nationale D'ingénieurs de Monastir; Ecole centrale Marseille, Marseille, France
 Aix-Marseille Université, CNRS, Ecole Centrale, Marseille, France
 Université de Monastir, Ecole Nationale D'ingénieurs de Monastir, Marseille, France
Intervertebral discs (IVD) are fibro-cartilages situated between vertebrae providing their joint flexibility. They play a major role in the transmission and absorption of load through the spine. The disc can undergo progressive structural and quantitative changes in its composition and morphology related to mechanical load applied to the spine which can lead to disc degeneration; this disease is ...