Aqui você encontrará apresentações realizadas nas Conferências de Usuários COMSOL de todo o mundo. As apresentações englobam pesquisas e produtos inovadores feitas por engenheiros e cientistas usando o COMSOL Multiphysics. Os tópicos abramgem uma grande gama de indústrias e aplicações, como elétrica, mecânica, escoamento e química. Use a função de busca "Quick Search" para encontrar apresentações na sua área de interesse.

Simulation of Supercritical Fluid Extraction Process

P. Katiyar [1], S. Khanam [1],
[1] Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, India

This paper deals with the simulation of mathematical model for supercritical extraction. Reverchon, 1996 extracted sage oil using supercritical extraction method from sage leaves at 9 MPa and 50 ᵒC. Four mean size of sage leaves ranging from 0.25 to 3.10 mm were taken for extraction with other experimental conditions and process parameters. Experimental results were fitted in the model developed ...

Undergraduate Studies of Supersonic Flow from a Converging-Diverging Nozzle

K. Stein[1], N. Gessner[1], R. Peterson[1], A. Wiedmann[1]
[1]Department of Physics, Bethel University, St. Paul, MN, USA

Undergraduate studies are carried out to examine the supersonic flow from an axisymmetric converging-diverging nozzle. Flow in the nozzle is initiated by the rupture of a diaphragm that is positioned between the nozzle and a 1-gallon pressurized air tank. Simulations are carried out in COMSOL Multiphysics® for unsteady, axisymmetric flow with the High Mach Number interface of the CFD Module. ...

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 ...

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 ...

Transient Simulation of the Electrolyte Flow in a Closed Device for Precise Electrochemical Machining - new

M. Hackert-Oschätzchen[1], M. Penzel[1], M. Kowalick[1], G. Meichsner[2], A. Schubert[1,2]
[1]Professorship Micromanufacturing Technology, Technische Universität Chemnitz, Chemnitz, Germany
[2]Fraunhofer Institute for Machine Tools and Forming Technology, Chemnitz, Germany

Precise electrochemical machining (PEM) is an innovative machining technology which results from further development of the electrochemical sinking. PEM works with pulsed low frequency direct current and oscillation of the tool electrode. As part of the project ‘Electrochemical machining of internal precision and micro-geometries with high aspect ratios by process-state-dependent electrolyte ...

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 ...

The Transient Modeling of Bubble Pinch-Off Using an ALE Moving Mesh

C.J. Forster, and M.K. Smith
Georgia Institute of Technology, Atlanta, GA, USA

The use of an acoustic field to control the boiling process has the potential to increase the overall rate of heat transfer and delay the critical transition to film boiling. This system is being investigated through the development of a model of a single boiling bubble near a flat, heated, horizontal surface in the presence of an acoustic field. The dynamics of the bubble interface is ...

Optimization of Extrusion Processes for non-Newtonian high-Viscous Fluids with Wall Slip and Shear Thinning Effects

W. Hoffmann[1], M. Scholz[1]
[1]SiCo-Solutions, Stuttgart, Germany

Simulation of the flow behaviour of non-Newtonian fluids with high viscosities leads to special material models with specific material parameters. In this presentation, a material model consisting of 4 material parameters describing the flow itself and also the wall slip is presented. The investigations of the flow behaviour are based on COMSOL Multiphysics® using the Modules CFD, Structural ...

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 ...