Articles techniques et présentations

Ici vous trouverez les présentations issues des Conférences COMSOL à travers le monde. Réalisées par des utilisateurs de COMSOL Multiphysics, ces présentations explorent tous les domaines actuels d'innovation. Les applications couvrent pratiquement tous les secteurs industriels et impliquent des phénomènes électriques, mécaniques, fluidiques et chimiques. Utilisez la recherche rapide pour trouver les présentations les plus intéressantes dans votre domaine d'intérêt.

Hydraulic Design of Activated Sludge Tanks with CFD

A. J. Bosma, and B. A. Reitsma
Tauw bv, Deventer, The Netherlands

The hydraulic design of wastewater treatment plants (WWTP) is usually based on general guidelines and experience. Research and development in this field is mainly focused on understanding and improvement of the biological processes. In this article we present modeling of the activated sludge tanks of the wastewater treatment plants in Amsterdam-West and Eindhoven. For both locations, a number of ...

Turbulent Compressible Flow in a Slender Tube

K.O. Lund[1], C.M. Lord[2]
[1]Kurt Lund Consulting, Del Mar, CA, USA
[2]Lord Engineering Corp., Encinitas, CA, USA

Pressure-drop experiments were conducted for the turbulent, compressible flow of air in a small, slender tube, and modeled with COMSOL heat transfer module, and analytically. A scalar integration variable is introduced which integrates the mass velocity [kg/m²s] over the inlet area and iteratively equates this to the input mass flow [kg/s]. For computation, the temperature specification is ...

Numerical Study of the Self-ignition of Tetrafluoroethylene in a 100-dm3-reactor

F. Ferrero[1], M. Kluge[1], R. Zeps[1], T. Spoormaker[2]
[1]BAM Federal Institute for Materials Research and Testing, Berlin, Germany
[2]Chairman PlasticsEurope Fluoropolymers TFE Safety Task Force, Du Pont De Nemours, Dordrecht, The Netherlands

The self-ignition of tetrafluoroethylene (TFE) caused by contact with hot surfaces has been analyzed with the help of simulations performed with COMSOL Multiphysics®. The current study focuses on large-scale heated reactors for the industrial production of polytetrafluoroethylene (PTFE) from TFE at high pressures. Simulations of the self-heating and consequent self-ignition of TFE in a ...

Miscible Viscous Fingering of Pushed Versus Pulled Interface

S. Pramanik[1], M. Mishra[1]
[1]Indian Institute of Technology Ropar, Rupnagar, Punjab, India

Viscous fingering (VF) instability has been extensively studied over past several decades in the context of various industrial, environmental and chemical processes. We try to model miscible VF at pushed or pulled interfaces using COMSOL Multiphysics®. We study the effect of the positive and negative log-mobility ratio on the fingering instability. Numerical simulation has been performed in 2D ...

Mean Flow Augmented Acoustics in Rocket Systems - new

S. Fischbach[1]
[1]NASA Marshall Space Flight Center / Jacobs ESSSA Group, Huntsville, AL, USA

Combustion instability in solid rocket motors and liquid engines has long been a subject of concern. Recent advances in energy based modeling of combustion instabilities require accurate determination of acoustic frequencies and mode-shapes. Of particular interest is the acoustic mean flow interactions within the converging section of a rocket nozzle, where gradients of pressure, density, and ...

3-D COMSOL Analysis of Extruder Dies

E. Solomon[1] and V. Mathew[1]
[1]Arcada University of Applied Sciences, Espoo, Finland

Three-dimensional flow analysis was performed by using COMSOL Multiphysics Chemical Engineering Module for the purpose of analyzing the flow properties and finding out the operating points of a test domain. Using material property table for an exemplary melt of LDPE (Low-Density Polyethylene), the logarithmic viscosity-shear rate graph was plotted and fitted to the 4–constant modified Carreau ...

Using COMSOL Multiphysics to Model Viscoelastic Fluid Flow

B.A. Finlayson
Department of Chemical Engineering, University of Washington

Viscoelastic fluids have first normal stress differences even in rectilinear flow. Thus, they are more complicated than purely viscous non-Newtonian fluids modeled as a power-law model or Carreau model. Viscoelastic effects must be included when modeling the flow of polymer melts and concentrated polymer solutions in situations for which the normal stresses matter. The extrudate swell problem ...

An Analysis of Skimboard Hydrodynamics

N.D. Barnett[1], and E. Gutirrez-Miravete[2]
[1]General Dynamics-Electric Boat, Kingston, Rhode Island, USA
[2]Rensselaer at Hartford, Hartford, Connecticut, USA

This paper report on a study of the hydrodynamics of skimboards and surfboards using the computational fluid dynamics (CFD) module in COMSOL. The study analyzes the flow in a thin water layer underneath a skim board in a 2-D Cartesian coordinate. Three different sets of boundary conditions were employed and one of them produced the best agreement with previous findings.

The Use of CFD Simulations in Learning Fluid Mechanics at the Undergraduate Level

Marc K. Smith
Professor of Mechanical Engineering, Georgia Institute of Technology

Simple, accurate CFD simulations using COMSOL Multiphysics are used in a senior-level undergraduate course as a means to explore a number of fluid flows with the intent of developing a deep understanding of the underlying fluid mechanical mechanisms involved in the flows. Students also learn about the finite element method, how to properly pose the underlying mathematical model for the fluid ...

Flow Modeling in a Flat Membrane Module

B. Balannec1, J. M. Gozálvez-Zafrilla2, D. Delaunay1, and M. Rabiller-Baudry1
1UMR - "Sciences Chimiques de Rennes", Université de Rennes, Rennes, France
2Departamento de Ingeniería Química y Nuclear, Universidad Politécnica de Valencia, Valencia, Spain

A CFD calculation of the complex three dimensional flow in a flat membrane module (Rayflow X100, Orelis- Novasep) was made under the conditions of a typical fouling study in order to compare velocity distribution to fouling deposit (with charcoal). The flow was turbulent in the inlet/outlet pipes of the module and laminar in the channel containing the membrane. The local Reynolds number was ...

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