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.

Material Flow around a Bobbin Tool for Friction Stir Welding

J. Hilgert, L. Hütsch, J. Dos Santos, and N. Huber
GKSS Forschungszentrum GmbH, Geesthacht, Schleswig-Holstein, Germany

This study presents an approach to model the material flow around a bobbin tool for Friction Stir Welding (FSW). In this CFD model the aluminum is treated as a highly viscous non Newtonian shear thinning liquid. The model is formulated in a 3D Eulerian frame. The temperature field and the desired torque acting on the tool are taken from a 3D thermal pseudo mechanical model implemented in ...

Boundary Value Effects on Migration Patterns in Hydraulically Fractured Shale Formations - new

T. Aseeperi[1]
[1]Department of Chemical Engineering, University of Arkansas, Fayetteville, AR, USA

During the hydraulic fracturing process, there can be possible re-activation of closed/sealed faults and natural fractures in the formation, which may lead to changes in the boundary conditions of the reservoir. While study models of shale gas formations have utilized the concept of a closed reservoir in order to optimize the production of gas in the well-bore, this assumption cannot be adopted ...

Comparison of Industrial Agitation for Batch Reacting Vessel Mixing in Bioethanol Fermentation

H. Rana [1],
[1] Loughborough University, United Kingdom

This paper presents the investigation into the phenomena during batch reactor vessel mixing comparing agitation equipment; the Rushton turbine and the Marine propeller; in the production of bioethanol by yeast fermentation. The key factors addressed in selecting equipment were fluid vector flow, energy dissipation resulting in shear damage to yeast cells, agitation power consumption, critical ...

Design and Simulation of MEMS Micro Heater for DNA Amplification

D. Sharma [1], A. Siddiqua [1],
[1] Nitte Meenakshi Institute of Technology, Bengaluru, Karnataka, India

PCR (Polymerase Chain Reaction) is a recent well researched technique which can be employed to obtain an amplified DNA (Deoxyribonucleic Acid). A continuous flow polymerase chain reaction with integrated MEMS based design micro heater for DNA amplification is implemented. Temperature zone is obtained by natural heat conduction rather than making use of typical silicon thermal cycler. Inter ...

Modeling an Ejector for Hydrogen Recirculation in a PEM Fuel Cell

X. Corbella [1], R. Torres [2], J. Grau [2], M. Allué [3],
[1] Escola Universitària d’Enginyeria Tècnica Industrial de Barcelona (Universitat Politècnica de Catalunya), Barcelona, Spain
[2] Fluid Mechanics Department (Escola Universitària d’Enginyeria Tècnica Industrial de Barcelona - Universitat Politècnica de Catalunya), Barcelona, Spain
[3] Institut de Robòtica I Informàtica Industrial (Consejo Superior de Investigaciones Científicas – Universitat Politècnica de Catalunya), Barcelona, Spain

PEM Fuel Cells’ durability and performance can be increased using an ejector based hydrogen recirculation system. In this work, a CFD model has been implemented to simulate the flow within an ejector used to recirculate hydrogen in PEM Fuel Cell systems. The model has been validated experimentally and has been used to design and manufacture an ejector that will be implemented in a fuel cell test ...

Optimization of Flow Distribution in the Feed Sparger of a Steam Drum

P. Goyal[1], A. Dutta[1], and A. K. Ghosh[1]
[1] Reactor Safety Division, Bhabha Atomic Research Centre, Trombay, Mumbai, Maharashtra, India

Steam drums of a nuclear power plant separate steam from the steam water mixture and sub cooled incoming feed water returns to the reactor. The entire feed water flow is delivered to the steam drum through the feed water sparger. The feed water sparger is provided with number of inverted ‘j’ type lateral tubes to  distribute the feed water in the drum for proper mixing with the separated ...

A Multiphysics Approach to the Modeling of Biological Prosthetic Heart Valves

A. Avanzini[1], D. Battini[1], M. Berardi[1]
[1]Università degli Studi di Brescia, Brescia, Italy

The complex behavior of biological prosthetic heart valves was simulated. A multiphysics computational approach was adopted using different modules of COMSOL Multiphysics: the LiveLink(TM) interface was used to exchange the valve geometry with CAD, Structural Mechanics Module to set loads, boundary conditions and implement anisotropic hyper-elastic constitutive laws for leaflet tissue, PDE to ...

Mechanistic Modeling of Non-Spherical Bacterial Attachment on Plant Surface Structures

A. Warning [1], A. K. Datta [1],
[1] Cornell University, Ithaca, NY, USA

The particle tracking model provided a deeper understanding to the experimental results. The model showed good agreement with experimental data for rotation, transport and attachment. In the attachment model, protrusions create low velocity, low shear regions increasing attachment while holes pull cells toward the surface and increase residence time on the surface increasing attachment rate.

Design of an Anisokinetic Probe for Sampling Radioactive Particles from Ducts of Nuclear Facilities

P. Geraldini [1],
[1] Sogin Spa, Rome, Italy

The aim of this study is to design a new concept of shrouded probe that meets the ISO 2889 requirements and it is suitable for small-ducts installation. In order to reduce the construction costs they have been considered standard stainless steel welding fittings manufactured according to ASME/ANSI specifications. In particular, with the numerical simulations, they have been firstly evaluated ...

MCA 动脉瘤血流动力学分析

刘孟杰 [1], 付芳芳 [2], 李萌 [1]
[1] 郑州大学,郑州,河南,中国
[2] 郑州大学附属省人民医院,郑州,河南,中国

动脉瘤破裂是引起蛛网膜下腔出血的一种主要原因。结合 COMSOL Multiphysics® 灵活的几何建模特性以及强大的流体仿真求解能力,本文分别对两组不同大小关系的 MCA 动脉瘤理论模型进行了仿真建模分析。通过模拟分析,获得了动脉瘤球囊体长度和宽度与动脉瘤基底宽度不同比例条件下的动脉瘤速度、压力、壁面切应力(WSS)等参数的变化规律,分析了几何形态与动力学参数之间的关系。模拟结果显示:1、宽颈动脉瘤,瘤体内部旋流强度较之窄颈动脉瘤更强,中心区流速更低,更有利于形成血栓而且顶点处压力更大,更易破裂。2、增大动脉瘤宽度与基底直径的比值,顶点处 WSS 呈非线性增长,但最大值低于 WSS 安全范围的下限值,破裂危险性依然很高;3、动脉瘤宽度与基底直径不同比例下的最大的 WSS 均是主要集中在动脉瘤与载瘤血管结合处(第一剪应力集中区),对血管壁生物组织力学特性影响严重;WSS ...