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.
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Optimization of a Rotor Shape for Spherical Actuator with Magnetically Levitating Rotor to Match Octupole Field Distribution

M. Sidz[1], R. Wawrzaszek[1], L. Rossini[2], A. Boletis[3], S. Mingard[3], K. Seweryn[1], E. Onillon[2], M. Strumik[1]
[1]Space Research Centre of PAS, Warsaw, Poland
[2]CSEM Centre Suisse d’Electronique et de Microtechnique SA, Neuchâtel, Switzerland
[3]Maxon Motor AG, Sachseln, Switzerland

The use of a reaction sphere as an actuator used by satellite Attitude Control System was proposed over twenty years ago. In principle this concept assumes the use of a single reaction sphere which can be accelerated in any direction instead of a set of reaction wheels. The solution discussed in this work has been proposed and patented by CSEM company. Contrary to conventional ball bearing ...

COMSOL Multiphysics Applied to MEMS Simulation and Design

Dr. Piotr Kropelnicki[1]
Mu Xiao Jing[1]
Wan Chia Ang[1]
Cai Hong[1]
Andrew B. Randles[1]

[1]Institute of Microelectronics, Agency for Science, Technology and Research, Singapore, Singapore

In this research, we performed multiple COMSOL Multiphysics® simulations. We analyzed the dispersion curves of waves in a LAMB wave pressure sensor; simulated a thin metal film in a microbolometer and observed the resulting stress; investigated the thermal behavior of an acoustic wave microbolometer; and modeled the fluid-structure interaction (FSI) for piezoelectric-based energy harvesting from ...

Near-Wall Dynamics of Microbubbles in an Acoustical Trap - new

L. Wright[1], G. Memoli[1], P. Jones[2], E. Stride[3]
[1]National Physical Laboratory, Teddington, UK
[2]University College London, London, UK
[3]University of Oxford, Oxford, UK

Understanding the interactions between microbubbles and surfaces is key to the successful deployment of microbubbles in a range of applications. Two important examples are their use as a drug delivery mechanism, and their potential use of acoustically-driven bubbles as microscale sensors. Drug delivery with bubbles involves sonication at high frequency close to a boundary, and sensing with ...

Mean Flow Augmented Acoustics in Rocket Systems - new

S. Fischbach[1]
[1]NASA Marshall Space Flight Center / Jacobs ESSSA Group, Huntsville, AL, USA

Combustion instability in solid rocket motors and liquid engines has long been a subject of concern. Recent advances in energy based modeling of combustion instabilities require accurate determination of acoustic frequencies and mode-shapes. Of particular interest is the acoustic mean flow interactions within the converging section of a rocket nozzle, where gradients of pressure, density, and ...

Development of a RheoDSC, an Instrument for Simultaneous Rheological and Calorimetric Measurements

L. Van Lokeren [1], R. Verhelle [1], C. Block [1], P. Van Puyvelde [2], G. Van Assche [1]
[1] Vrije Universiteit Brussel, Brussels, Belgium
[2] Catholic University of Leuven, Leuven, Belgium

Transformations in polymers, such as polymerisation, melting/crystallization, and phase separation/remixing, are associated with changes in both rheological and thermal properties. To permit simultaneous calorimetric and rheometric measurements, the RheoDSC was developed. The RheoDSC combines two commercial instruments, a TA Instruments Q2000 DSC and a TA Instruments AR-G2 dynamic rheometer. A ...

Janus 颗粒自驱运动的数值模拟

崔海航 [1], 王雷磊 [1], 谭晓君 [1],
[1] 西安建筑科技大学,西安,陕西,中国

Janus 颗粒是由物理或化学性质不同的两部分所构成的颗粒的总称。由于其结构的特殊性以及自驱动特性使其在MEMS、药物传输等领域有着潜在的应用价值。本文基于COMSOL Mutiphysics® 4.3a 多物理场耦合模拟平台对不同形状的 Pt-SiO2 型 Janus 颗粒的在不同浓度 H2O2 溶液中的自扩散泳动进行了数值模拟,并进一步研究模拟了球形 Janus 颗粒的近壁面运动。

Predicting Critical Current as a Function of Magnetic Field in High-Temperature Superconductors

J. Doody [1], P. Michael [1], R. Vieria [1], W. Beck [1], L. Zhou [1], J. Irby [1],
[1] Massachusetts Institute of Technology - Plasma Science and Fusion Center, Cambridge, MA, USA

REBCO tapes belong to a class of high-temperature superconductors (HTS) that can be superconducting at liquid nitrogen temperatures (77K) as opposed to typical superconductors such as Nb3Sn which need to operate at liquid helium temperatures (4K). One important aspect of designing a super conducting coil is the ability to predict the critical current above which the conductor becomes ...

Modeling of a Direct Methanol Fuel Cell

J. Drillet [1],
[1] DECHEMA-Forschungsinstitut, Frankfurt, Germany

This work aims at the modelling of a 5 cm^2 Direct Methanol Fuel Cell (DMFC) with mixed serial/parallel serpentine flow fields in terms of current/voltage behavior. One of the main challenge to overcome consists on lowering the so-called methanol cross over from the anode through the polymer membrane to the cathode that is responsible for mixed-potential formation at the cathode where both ...

基于 COMSOL 的 PVT 法 AlN 晶体生长仿真:温场对生长驱动力的影响研究

金雷 [1],
[1] 中国电子科技集团公司第四十六研究所,天津,中国

分别从软件模拟和晶体生长实验两方面对衬底表面的温度分布进行研究,进而达到控制 AlN 蒸气在衬底表面过饱和度的目的。理论上,结合异质形核理论(图1 (a)-(c)),采用 COMSOL Multiphysics® 模拟软件对坩埚结构的温度分布进行模拟仿真(图1(d)),模拟结果表明:复合型衬底可以显著地改变衬底表面的温度分布,进而改变衬底表面 AlN 气氛的过饱和度,实现对晶体生长驱动力[1]的控制;实验上,采用 PVT 法 AlN 晶体的生长实验验证了软件模拟结果。采用复合型衬底生长 AlN 晶体时,通过对衬底表面的温度分布调控,如图1 (c)-(g)所示,可有效地控制晶体生长驱动力,进而实现形核位置和形核数量的控制[2,3],经过 6~10 h AlN 晶体生长后,可获得较大直径的 AlN 单晶。拉曼光谱和 XRD 双晶摇摆曲线测试[4]结果表明,晶体具有很好的结晶性能。

电力母线板稳态、瞬态多物理场模型差异分析

程屾 [1], 刑燕好 [1]
[1] 沈阳工业大学,沈阳,中国

随着电力工业的快速发展,母线板作为汇集、分配和传送电能的装置,广泛应用于各个电工领域。由于流过母线板的电流一般较大,其温升发热问题不容忽视。该问题涉及电磁场、温度场、流场及位移场等多个物理场的综合。为了更好地研究其发热散热问题,本文采用 COMSOL Multiphysics® 多物理场直接耦合分析软件,基于有限元理论,在考虑设备几何形状和材料物理特性影响的基础上,对母线板进行三维建模。分别在瞬态和稳态情况下对母线板进行电—热—力耦合场分析,电—热—流耦合场分析,从而研究母线板的温度、电流密度分布规律和由于热膨胀引起的形变大小。最后加入层流,分析在考虑气流冷却效应时,母线板的散热情况,并对仿真结果进行研究分析。