In questa sezione troverete i lavori presentati alle Conferenze mondiali COMSOL. Le presentazioni descrivono ricerche e prodotti innovativi progettati con COMSOL Multiphysics da colleghi di tutto il mondo. I temi delle ricerche presentate abbracciano un'ampia gamma di settori produttivi e aree applicative, in ambito elettrico, meccanico, fluidodinamico e chimico. Lo strumento di Ricerca Rapida vi permetterà di trovare le presentazioni che si riferiscono all'area di vostro interesse.
COMSOL News Magazine 2017

Computational Evaluation of Improved Anaerobic Digestion Reactor Designs

A. A. Forbis-Stokes [1], M. A. Deshusses [1],
[1] Duke University, Durham, NC, USA

The purpose of this study was to investigate the impact on number of baffles placed in horizontal- or vertical-alignment of an anaerobic baffled reactor (HABR and ABR, respectively). Computational fluid dynamics was used to evaluate hydraulic performance of each and determine what number of compartments should be used to optimize reactor volume while adding minimal complexity. The findings ...

COMSOL Multiphysics for Efficient Solution of a Transient Reaction-Diffusion System with Fast Reaction

M.K. Gobbert[1], A. Churchill[1], G. Wang[1], and T.I. Seidman[1]
[1]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 ...

Using Computational Fluid-Dynamics (CFD) for the Evaluation of Tomato Puree Pasteurization: Effect of Orientation of Bottle - new

A. R. Lespinard[1, 2], R. H. Mascheroni[1, 2]
[1]Centro de Investigación y Desarrollo en Criotecnología de Alimentos (CIDCA), La Plata, Buenos Aires, Argentina
[2]Universidad Nacional de La Plata (UNLP), La Plata, Buenos Aires, Argentina

Determination of the temperature in liquid foods may be derived by measurements or by modeling. However, the placement of thermocouple probes to record temperature in the container disturbs the flow patterns. For this purpose, Computational fluid-dynamics (CFD) offers a powerful tool for predictions of the transient temperature and velocity profiles during natural convection heating of liquid ...

Effect of Permeability Diminution in Nutrient Diffusion in Intervertebral Disc

M. A. Chetoui [1], O. Boiron [2], A. Dogui [3], V. Deplano [2],
[1] Université de Monastir, Ecole Nationale D'ingénieurs de Monastir; Ecole centrale Marseille, Marseille, France
[2] Aix-Marseille Université, CNRS, Ecole Centrale, Marseille, France
[3] 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 ...

Chemical Reactions at Interfaces During Droplet Formation in Microchannels

Simeon Cavadias [1], Cédric Guyon [2], Gerrardo Vera De la Cruz [3],
[1] Institut Pierre-Gilles de Gennes (IPGG) - UPMC, France
[2] Chimie-ParisTech - Institut Pierre-Gilles de Gennes (IPGG) , France
[3] Master Nuclear Energy, ISTN (Saclay), France

Emulsions, small liquid droplets of oil in water or water in oil, find wide application in, pharmaceutical products, fine chemicals, analytical chemistry. Microfluidic devices allow creation of uniform droplets with a tight distribution. The COMSOL Multiphysics® software model presented here is an extension of the tutorial “Droplet Breakup in a T- junction”. In this tutorial uniform droplets ...

Analyzing a Malfunctioning Clarifier with COMSOL’s Mixture Model

A. de Niet, A. van Nieuwenhuijzen, and A. Geilvoet
Witteveen+Bos, Deventer, The Netherlands

Clarifiers are used to separate sludge and water in waste water treatment plants. In this paper we analyze a malfunctioning clarifier using the mixture model. We are able to receive model results that are reasonably close to measurements from the real clarifier. With the model we can explain the bad separation of water and sludge in the clarifier. Engineers have proposed several actions in order ...

Modeling Flow and Deformation during Hot Air Puffing of Single Rice Kernels

T. Gulati[1], A. Datta[1]
[1]Cornell University, Ithaca, NY, USA

When rice is subjected to intense heating, it results in rapid evaporation of liquid water to vapor. As a consequence, large pressures are generated within the kernel in a span of 15s resulting in large volume changes causing the kernel to puff rapidly. Under suitable conditions, the ratio of initial volume to volume after puffing could be as high as 10. Rice puffing process is a complex ...

Determination of the Load-dependent Thermal Conductivity of Porous Adsorbents

O. Kraft [1], J. Gaiser [1], M. Stripf [1],
[1] University of Applied Sciences, Karlsruhe, Baden-Würtemberg, Germany

Standard measuring techniques for thermal conductivity cannot be readily applied to determine the load-dependent thermal conductivity of porous adsorbents, because the local ad- and desorption inside the specimen and the thickness of the specimen are not considered. Hence, in this work a new measuring procedure combining the transient hot bridge (THB) with a three dimensional finite element ...

Study of a Self Heating Process of Tetrafluoroethylene by the Exothermic Dimerization Reaction to Octafluorocyclobutane

M. Beckmann-Kluge[1], H. Krause[1], V. Schröder[1], A. Acikalin[2], and J. Steinbach[2]
[1]Federal Institute for Materials Research and Testing, Berlin, Germany
[2]Technical University Berlin, Berlin, Germany

The self heating process of Tetrafluoroethylene caused by an exothermic dimerization reaction was studied. The heat of reaction can lead to a thermal explosion by the decomposition of the Tetrafluoroethylene. Different reaction kinetics, including multistep kinetics, were used to describe the mass balance. The COMSOL Chemical Engineering Module was used to perform the simulation which was ...

Modeling of Fluid Flow and Heat Transfer During a Steam-Thermolysis Process for Recycling Carbon Fiber Reinforced Polymer

A. Oliveira Nunes[1], Y. Soudais[1], R. Barna[1], A. Bounacer[1], Y. Yang[1]
[1]Centre RAPSODEE - Ecole des Mines d'Albi, Albi, France

Different types of technologies to recycle carbon fiber reinforced polymer (CFRP) waste have been studied, for example: pyrolysis, solvolysis and steam-thermolysis. The steam-thermolysis is a process that combines pyrolysis and superheated steam at atmospheric pressure to decompose the organic matrix of the composite. The waste is introduced into a bench-scale reactor heated at high temperatures ...