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 abrangem 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.

DNA Interactions in Crowded Nanopores - new

K. Misiunas[1], N. Laohakunakorn[1], S. Ghosal[2], O. Otto[1], U. F. Keyser[1]
[1]University of Cambridge, Cambridge, UK
[2]Northwestern University, Evanston, IL, USA

The motion of DNA in crowded environments is a common theme in physics and biology. Examples include gel electrophoresis and the self-interaction of DNA within cells and viral capsids. Here we study the interaction of multiple DNA molecules within a nanopore by tethering the DNA to a bead held in a laser optical trap to produce a "molecular tug-of-war". We measure this tether force as a function ...

Use of COMSOL Multiphysics® for IAQ Monitoring in Cleanrooms - new

G. Petrone[1], C. Balocco[2]
[1]BE CAE & Test, Catania, Italy
[2]Department of Industrial Engineering, University of Firenze, Firenze, Italy

High levels of Indoor Air Quality (IAQ) in Operating Theatres (OT) is an important issue in order to contribute in prevention of Surgical Site Infections (SSI). Despite of specific plant layouts are applied for OT ventilation (e.g. unidirectional flow), the effective use conditions can heavily modify the design microclimate and air quality levels. Medical staff presence and movements and sliding ...

3D-FEA of the Relationship between the Occiput and Sphenoid in the Osteopathic Paradigm - new

Y. Chiesa[1]
[1]Istituto Superiore di Osteopatia, Milan, Italy

The concept of cranial Primary Respiratory Mechanism (MRP) is used by osteopathic practitioners to explain the perceptual characteristics arising from the clinical palpation approach of the human skull. The theoretical apparatus and the same MRP existence is always element of controversy among the scientific community. The results arising from this study highlight the intrinsic capability of ...

A 3D Thermal Model for Lunar Surface Using COMSOL Multiphysics® Software: Validation and Results

K. Durga Prasad [1], S.V.S. Murty [1], V. K. Rai [1],
[1] Planetary Sciences Division, Physical Research Laboratory, Ahmedabad, Gujarat, India

A comprehensive three dimensional finite element thermal model has been developed using COMSOL Multiphysics® software to understand the thermo-physical behaviour of the uppermost regolith layer of the moon. The model can simulate variable layers, layer thickness and dimensions and can account for complex geometry, different size, irregular meshing, parametric based variation in physics and ...

带螺旋翅片的绕管负压换热器

王坤祥 [1],
[1] 中国科学院理化技术研究所,北京,中国

引言:超流氦低温系统的正常运行离不开负压换热器,在此选用绕管式的负压换热器。其工况为4.45K~2K之间,低压侧绝对压力3000Pa左右。软件中用到的模块有Livelink for Solidworks、Livelink for Excel、“非等温湍流 k-ε”接口。 结果:求解结果定性上正确,问题在于为了让换热器达到理想换热效果,需要更多匝数的绕管,对计算机要求很大,在该模型中只保留了10匝。

自电泳机理驱动的微纳米马达仿真模拟研究

王威 [1], 周超 [1],
[1] 哈尔滨工业大学深圳研究生院,深圳,中国

微纳米马达是一种能将周围环境的能量转化为自身自主运动的新型智能仿生材料,其在药物的运输与释放,低维材料的合成以及软物质研究中有着重要的应用[1]。基于自电泳的双金属棒马达是研究时间最长的一类马达,它有着与自然界中类似的自组装和群体行为的特性[2]。但是其运动机理复杂且涉及到多个物理场的紧密耦合,这就为其进一步的研究和应用带来了一定的困难。 COMSOL Multiphysics® 可以方便地进行多物理场的模拟。图(1)展示了双金属棒的自电泳机理, 由于棒两端的化学反应造成了带电离子浓度的分布不均匀,进而产生自生电场驱动马达运动。其中传质过程、流体流动以及电场形成相互影响,环环相扣[3]。基于以上物理过程,我们对 COMSOL 中稀物质传递,静电和蠕动流接口进行了有效的耦合,从而实现了马达周围离子场,电场和流场的模拟(图2),在此基础之上,我们研究了马达的运动速度(图3) ...

Transient Diffusion Modeling of Methane Plume and Source Localization

S. K. Nayaka[1],, S. Roya [1],, K. Ghosha [1],, S. Aroshb [2],, S. Prakashb[2],, S. P. Duttaguptaa [1][2]
[1] Center for Research in Nanotechnology and Science, IIT Bombay, Mumbai, Maharashtra, India.
[2] Dept. of Electrical Engineering, IIT Bombay, Mumbai, Maharashtra, India.

Methane detection and quantification is of great importance due to its natural abundance, potential to cause explosions and known greenhouse effect. Leak detection and concentration monitoring at source is highly challenging as CH4 is odorless and colorless. This can be performed mounting sensor network over a potential diffusion area. It requires optimal positioning of those sensor nodes to ...

基于多物理场耦合方法分析熔盐堆工况

张海黔 [1], 刘国财 [1], 王凯凯 [1],
[1] 南京航空航天大学,南京,中国

熔盐堆是唯一一种以液态为燃料的反应堆,熔盐堆研究不同于其他反应堆。本文采用多物理场耦合方法模拟熔盐堆发生工况时熔盐堆中一些参数的变化[1-4]。我们将反应堆模型简化为一个石墨围成的空腔结构,如图[1a]。为简化计算采用二维轴对称图形,如图[1b]。分别采用流体流动接口中单向流中的湍流模式模拟熔盐流体流动、传热模块中流体传热模拟熔盐传热、传热模块中固体传热模拟石墨传热、稀质传递接口模拟反应堆中先驱核浓度、系数型偏微分方程模拟中子扩散。基于以上五个物理场耦合的情况下对一回路发生失流以及石墨发生膨胀两种工况下研究熔盐堆温度变化及先驱核浓度的变化。结果表明一回路流速减小会导致反应堆温度明显升高,如图[2],流速在5m/s减小到1m/s时温度升高不明显,由1m/s减小变化到0m/s时温度变化呈指数升高。先驱核浓度会随着流速减小先增大后减小,如图[3]。当一回路石墨发生膨胀时 ...

Modeling Bacterial Transport and Removal in a Constructed Wetland System

E. Engström, B. Balfors, and R. Thunvik
Royal Institute of Technology, Stockholm, Sweden

In this study we evaluate transport, retention and subsistence of Escherichia coli (E. coli), a common fecal indicator bacteria, in a model (2x1m) of a constructed wetland. Transport occurs in the unsaturated and saturated zone. Inactivation is accounted for as a kinetic first-order process. Retention is assumed to be dominated by solid-air-water interface straining and is modeled with a kinetic ...

Microfluidic Separation System for Magnetic Beads

F. Wittbrach, A. Weddemann, A. Auge, and A. Hütten
Department of Physics, Bielefeld University, Germany

It is possible to control the motion of magnetic beads using a combination of hydrodynamic and electromagnetic forces. In this work, we investigate the possibility to manipulate the motion of beads with different magnetic moments in a special microfluidic structure so as to separate them. We also experimentally prove that this structure is a suitable device to separate beads and show that the ...