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.

Keyhole Behavior During Spot Laser Welding

V. Bruyere [1], C. Touvrey [2], P. Namy [1]
[1] SIMTEC, Grenoble, France
[2] CEA DAM, Is-sur-Tille, France

The formation of porosities in spot laser welding depends on complex thermo-hydraulic phenomena. To understand and control these mechanisms, the COMSOL Multiphysics® software is used to model both the interaction and cooling stages of an isolated impact made with a Nd:YAG pulsed laser. The model is based on the Phase Field method in order to apprehend the evolution of the liquid-gas interface ...

Reducing Solar Heat Gain from Inclined Buildings’ Roof by Using Radiant Barrier System

S. Ebrahim[1], A. Alshayji[1]
[1]Department of Mechanical Engineering, College of Engineering and Petroleum, Kuwait University, Kuwait City, Kuwait

The study produced a simulated model of natural convection in an inclined rectangular channel open ended with different locations of radiant barrier (RB) along the channel thickness(S). The upper plate is heated by various uniform constant heat fluxes while the inner surface of the lower plate has a very thin layer with low emissive aluminum foil. This model was used to adjust the location of ...

Application of Kelvin's Inversion Theorem to the Solution of Laplace's Equation Over a Domain That Includes the Unbounded Exterior of a Sphere

J. Russell[1]
[1]Florida Institute of Technology, Melbourne, FL, USA

In simulating physical systems modeled as solutions of partial differential equations over an unbounded domain, a challenge arises owing to the impossibility to cover an unbounded domain with a mesh. A classical problem in fluid dynamics, a solid sphere of radius a_s is submerged in a tank of water (at rest) of much larger size. The water is disturbed by the sphere’s sudden acceleration in the z ...

Simulation of an Impulse Arc Discharge in Line Lightning Protection Devices

A. Chusov [1], E. Rodikova [2], D. Belko [1],
[1] Streamer Electric Inc., Saint Petersburg, Russia
[2] Streamer Electric Inc. and Saint Petersburg State University, St. Petersburg, Russia

Line lightning protection devices (LLPD) nowadays are widely used for lightning protection of overhead power lines. LLPD is composed of electrodes in series embedded in silicone rubber which all together forms sequence of spark gaps. When lightning overvoltage is applied it causes electrical breakdown in every spark gap. From this point spark gap starts to operate as discharge chamber, ...

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 ...

COMSOL Multiphysics® 在热发电用真空集热管设计中的应用

赵旭山 [1], 郝雷 [1], 蒋利军 [1], 米菁 [1], 杨海龄 [1],
[1] 北京有色金属研究总院,北京,中国

随着能源紧张、油价攀升,环境污染严重,利用可再生绿色能源又成为不懈努力的方向。槽式太阳能热发电技术具有兼容性强、对电网冲击小、性价比高、发电成本低、可存储可调度等特点,近年来得到了迅猛发展,其核心部件为高温太阳能真空集热管,如图1所示。本研究利用 COMSOL Multiphysics® 针对真空集热管真实工况下的动态过程开展研究,并在此基础上开展集热管结构的优化设计。 由图 1 可知:集热管在电站中服役工况下,槽面会聚的太阳光主要集中于集热管下半面,上半面接收的会聚太阳光较少;导热工质自吸收管一端进入,接收会聚太阳光辐照能量,从吸收管另一端流出,流入→流出过程中,导热工质被加热;集热管外表面与外部环境通过热辐射和对流两种方式换热;吸收管与玻璃罩管间形成的环形密闭高真空区域各内表面通过热辐射换热,不考虑对流;集热管两端支撑固定于聚光器上,由于本身自重和热应力,会产生一定形变。 ...

Validation of a CFD Study of Particle Distribution in Nuclear Workplace

P. Geraldini [1],
[1] Sogin S. p. A., Rome, Italy

Understanding the air flow patterns and aerosol trajectories in ventilated rooms can provide key information for determining where to place early warning and monitoring instruments, and how to minimize hazardous materials in the worker’s breathing zone. The dispersion within rooms can be influenced by complex interactions between numerous variables, but especially ventilation design and room ...

Simulation of the Flow of an Autonomous Spherical Ball inside a Pipeline

W. Chalgham [1], A. C. Seibi [1], M. Mokhtari [1],
[1] University of Louisiana at Lafayette, Lafayette, LA, USA

One of the limitations of pipelines performance and structural integrity assessment is the continuous inspection of possible leaks due to corrosion or other types of failure mechanisms. Efforts to develop new technologies started several decades ago where different inspection techniques were used to enhance pipelines structural integrity. However, although available technologies present some ...

Studying PEM Fuel Cells using Equation Based Simulation

J. Blackburn [1], N. McCartney [1],
[1] National Physical Laboratory, London, UK

We present computer simulation results for PEM fuel cells using COMSOL Multiphysics® software. We have developed novel PDE equations at NPL from first principles and these are more realistic than models typically used in literature. The theory includes Maxwell-Stephan and Nernst-Planck equations for the diffusion and electrochemistry as well as equations governing electrostatic and stress/strain ...

On The Modelling Of Electrowetting Using COMSOL Multiphysics

J.F. Dannenberg, J. Brinkert, and E.A.D. Lamers
Reden b.v., Hengelo (ov.), The Netherlands

One of the upcoming technologies in displays is that of the electrowetting displays. A surface can be covered by a colored oil or transparent water using a voltage to increase or decrease the wettability of the surface. A simulation of the behavior of such a thin film of oil in water, forced to move due an electrostatic field, has been made using the level-set, two-phase flow application mode ...