Finite Element Analysis of Transient Ballistic-Diffusive Heat Transfer in Two-Dimensional Structures - new
S. Hamian, T. Yamada, M. Faghri, K. Park
University of Utah, Salt Lake City, UT, USA
Lund University, Lund, Sweden
University of Rhode Island, Kingston, RI, USA
For the last two centuries, the conventional Fourier heat conduction equation has been used for modeling a diffusive nature of macroscale heat conduction by considering the energy conservation and Fourier's linear approximation of heat flux. However, it cannot accurately predict heat transport when the length scale is comparable to or smaller than the mean free path of thermal energy carriers or ...
E. S. Tschoepke, J. A. E. Mazzaferro, G. Paz
Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
Introduction: The main objective of the present work consists in modeling an arc welding heat source to allow predict peak temperature and cooling rate at specific points. The filler metal was deposited on a plate of 32mm thick with no chamfer, in bead on plate configuration, using five different preheat temperatures: -30°C, 30°C, 100°C, 150°C and 200°C. Use of COMSOL Multiphysics® software: ...
M. J. Hancock , N. Elabbasi ,
 Veryst Engineering, LLC., Needham, MA, USA
Organ-on-a-chip microdevices combine microfluidics, MEMS, and biotechnology techniques to mimic the multicellular architectures, tissue-tissue interfaces, physicochemical microenvironments, and vascular perfusion of the body. Such devices are being developed to provide better levels of tissue and organ functionality compared with conventional cell culture systems, and have great potential to ...
V. Bruyere , C. Touvrey , P. Namy 
 SIMTEC, Grenoble, France
 CEA DAM, Is-sur-Tille, France
The formation of porosities in spot laser welding depends on complex thermo-hydraulic phenomena. To understand and control these mechanisms, the COMSOL Multiphysics® software is used to model both the interaction and cooling stages of an isolated impact made with a Nd:YAG pulsed laser. The model is based on the Phase Field method in order to apprehend the evolution of the liquid-gas interface ...
P. Zilio , W. Raja , A. Alabastri , R. Proietti Zaccaria 
 Istituto Italiano di Tecnologia, Italy
 Istituto Italiano di Tecnologia, Italy
 Rice University, USA
The formation of space charge clouds is a well known problem that affects thermionic emitters in regimes of high current emission. Although some analytical models have been presented, suitable for 1D geometries, the modeling of the problem in complex 3D structures remains a challenge due to the mutual coupling between electron trajectories and field they produce. Here we propose a model able to ...
A. Pezzin, M. Giansetti, A. Ferri
Politecnico di Torino, Torino, Italy
Electric resistances are widely used as heating elements in domestic and industrial equipment; since process water contains calcium carbonate and calcium bicarbonate, limescale plays an important role on global efficiency of water-heating systems. Calcium carbonate has a very low thermal conductivity (2.2 W/(m*K)) and the carbonate deposit on the heating element causes a decrease of the overall ...
Diffusion and Reaction in Fe-Based Catalyst for Fischer-Tropsch Synthesis Using Micro Kinetic Rate Expressions - new
A. Nanduri, P. L. Mills
Department of Chemical & Natural Gas Engineering, Texas A&M University, Kingsville, TX, USA
Fischer-Tropsch synthesis (FTS) is a highly exothermic polymerization reaction of syngas (CO+H2) in the presence of Fe/Co/Ru-based catalysts to produce a wide range of paraffins, olefins and oxygenates, often known as syncrude. Multi-Tubular Fixed Bed Reactors (MTFBR) and Slurry Bubble Column Reactors (SBCR) are widely employed for FTS processes. The scale-up of MTFBR is complicated by the ...
V. S. Kshirsagar, P. M. Pawar
SVERI's College of Engineering, Pandharpur, Maharashtra, India
Effective suspension and settling are critical for controlling biomass retention in a biogas digester. This paper developed a Computational Fluid Dynamics (CFD) model to simulate the hydrodynamic characteristics of multiphase flow in biogas digester. This is carried out by using COMSOL Multiphysics® software for understanding the behavior of slurries of different viscosity. This study helps to ...
R. Purkayastha , S. Schleuter , G. Minton , S. Walus , M. Wild ,
 Oxis Energy Ltd, E1 Culham Science Centre, Abingdon, United Kingdom
OXIS Energy Ltd is a pioneer in the research and development of Lithium Sulfur batteries. Scaling up from R&D level coin cells to pouch cells for automotive use, engineering design and thermal management start to become critical. In this study, heat flow at various levels of the cell is investigated. We analyzed different heat flow scenarios of the cell, and found that standard pack arrangements ...
R. Verhelle, L. Van Lokeren, S. Loulidi, H. Boyd, G. Van Assche
Physical Chemistry & Polymer Science, Vrije Universiteit Brussel, Brussels, Belgium
Heerema Marine Contractors, Leiden, The Netherlands
COMSOL Multiphysics® software is used to model the field joint application process on carbon steel pipelines for deep sea crude oil transportation, taking into account not only heat transfer, cure kinetics, and crystallization, but also thermal, cure and crystallization shrinkage and the resulting interfacial thermal stresses. Experimental data from the raw materials are implemented in the model ...