Inverse Estimation of the Flow Resistivity Tensor of Open-Cell Foams from Experimental Data and Darcy’s Flow Simulations
C. Van der Kelen, P. Göransson, and N-E.Hörlin
Marcus Wallenberg Laboratory for sound and vibration research, KTH Aeronautical and Vehicle Engineering, Stockholm, Sweden
The flow resistivity tensor, which is the inverse of the viscous permeability tensor, is one of the most important material properties for the acoustic performance of open cell foams, used in acoustic treatments. Due to the manufacturing processes, these foams are most often geometrically anisotropic. This paper discusses the estimation of the flow resistivity tensor using an improvement of a ...
V. Hrubý, and R. Hrach
Department of Surface and Plasma Science, Charles University, Prague, Czech Republic
The computer simulation with COMSOL Multiphysics has become a widely used technique for the study of various problems in the field of plasma physics. Despite the increasing performance of computers, fully three-dimensional particle simulations still have got extremely high demands on hardware and computer time. Although many problems could be solved by fluid models, results obtained by these ...
Y.M. Carreño-Martinez, J.M. Gozalvez-Zafrilla, J.A. Mendoza-Roca, and A. Santafé-Moros
Universidad Politecnica de Valencia, Spain
Submerged membrane bioreactor (SMBR) is an efficient technology for wastewater treatment that combines biological process and membrane filtration in one single stage. In the most usual configuration, submerged membrane hollow fibers are set in several planes. Air is introduced from the bottom in order to supply oxygen to the microorganisms but also to reduce fouling over the membrane fibers. ...
L. Kowalski, L.C. Muñoz, M.D. Pumar, and V.J. Serres
Universidad Politécnica de Cataluña, Departamento de Ingeniería Electrónica, Barcelona, Spain
The purpose of this paper is to describe numerical electro-thermal simulations of the REMS wind sensor unit and the results obtained by using COMSOL Multiphysics. This device is a hot-film anemometer for 2D wind measurements, which does not have movable parts and is based on the air stream forced heat convection to the environment. This wind sensor works as a thermo-electrical transducer where ...
Verification and Time Performance Analysis of COMSOL v3.5a for Solving the Electromagnetic Problem in a Superconductor Slab
J. Lloberas, J. López, E. Bartolomé, and X. Granados
Universitat Politècnica de Catalunya, Barcelona, Spain
Escola Universitària Salesiana de Sarrià, Barcelona, Spain
Institut de Ciència de Materials de Barcelona, Barcelona, Spain
Numerical analysis based on finite element method (FEM) represents a powerful approach to solve electromagnetic problems. For instance, FEM methods have been broadly used to calculate the critical state current distribution in high temperature superconductors of various geometries. In the near future, we intend to develop a tool in COMSOL v3.5a for the analysis of power applications, such as ...
W. Booth, J. Schiffbauer, and B. Edwards
West Virginia University
Star City, WV
Ion-selective membranes can be used in lab-on-a-chip devices for various portable applications in this field. These devices can be used as concentrators for analytical chemistry and for micro-scale filtration. Here, a binary aqueous electrolyte solution in a microchannel has a potential bias applied across it and it is driven through an ion-selective membrane. Ion concentration gradients form ...
Using COMSOL to Support a Cost-Effective, Non-Destructive Evaluation Approach for Predicting Bolt Failure in Highway Bridges
A. Elyea, B. Doubek, G. Hubbard, and D. Ozevin
Department of Civil Engineering
University of Illinois at Chicago
The development of a quantitative nondestructive evaluation method, as an alternative to visual inspection, for inspecting pre-tensioned bolts in fracture critical bridges is presented. In order to understand the ultrasonic behavior of a wide variety of bolt geometries used in bridges, numerical models of nine different bolt geometries were developed. The numerical models included the ...
M. Hackert, G. Meichsner, and A. Schubert[1,2]
Micromanufacturing Technology, Chemnitz University of Technology, Chemnitz, Germany
Fraunhofer Institute of Machine Tools and Forming Technology, Chemnitz, Germany
Electrochemical Machining with a closed electrolytic free jet is a special procedure to generate complex micro structures by help of anodic dissolution. The work piece shape is fabricated by supplying an electrolytic current through an electrolyte jet ejected from a small nozzle. In this study COMSOL Multiphysics is used to simulate the electric current density in the jet and the dissolution ...
N. Jand, A. Scarpetta, and M. Stefano
Chemical Engineering Department, University of L’Aquila, L’Aquila, Italy
Faculty of Engineering, University of L'Aquila, L’Aquila, Italy
The modeling of sublimation form a rotating cylinder of solid naphthalene in a confined vessel has been performed by coupling the model of incompressible Newtonian fluid flow with the model of the dilute solutions. Preliminary a 2D axisymmetric system with swirl flow function for laminar and turbulent regimes has been considered. In the turbulent regime the RANS model with default parameter ...
Energy Exchange During Electron Emission from Carbon Nanotubes: Considerations on Tip Cooling Effect and Destruction of the Emitter
M. Dionne, S. Coulombe, and J. Meunier
Department of Chemical Engineering, McGill University, Montreal, Quebec, Canada
Murphy and Good general theory for electron emission from metal surfaces was used to predict the field-emission capabilities of ideal arrays of vertically aligned carbon nanotubes (VACNT). The Nottingham effect was taken into account in order to explain experimental observation of a localized cooling of the VACNT tips during field emission and the total destruction of very short emitters at ...