Here you will find presentations given at COMSOL Conferences around the globe. The presentations explore the innovative research and products designed by your peers using COMSOL Multiphysics. Research topics span a wide array of industries and application areas, including the electrical, mechanical, fluid, and chemical disciplines. Use the Quick Search to find presentations pertaining to your application area.

Core-shell structure induced high displacement in piezoelectric ceramics - new

Ziming Cai [1], Xiaohui Wang, Bingcheng Luo, Longtu Li [1],
[1] State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, PR China

Large strain is crucial for piezoelectric ceramics to be used as actuators. In this work, a piezoelectric composite with core-shell structure is proposed to pursue high strain at a low applied electric field. The core of the piezoelectric composite is typical ferroelectric material, while the shell is composed of non-ferroelectric material. The distribution of internal electric field and the ...

基于电流连续性方程的电晕放电仿真及其应用 - new

许浩珲 [1], 鲁一苇 [1], 杨勇 [1],
[1] 华中科技大学

电晕放电是高电压技术的应用方向之一,它广泛应用于生物医学、水污染处理、纳米材料制造、静电除尘、材料表面改性以及新型人工降雨等领域。 电晕放电的数值模拟研究开始于四十年前,而在近十几年得到了迅猛发展。其最大的难点在于机理上具有高度的非线性、空间上存在多尺度等问题,这对于数值模拟研究来说是个很大的困难。时至今日,在相对较大的空间尺度仍未出现较为精确的仿真方法与模型。本文利用电流连续性原理,并结合经验公式,提出一种具有自洽性以及工程实用性的简化模型,大大提高了电晕放电计算的效率,节约计算内存以及计算时间,其结果也具有工程指导意义。 本文使用 COMSOL 的静电模块以及PDE偏微分方程模块,联立求解泊松方程、电势与电场强度的关系方程、电流密度方程以及电流连续性方程,并结合Peek经验公式以及Kaptsov假设,使用优化求解器进行迭代来确定边界条件,仿真所得电流 ...

直流GIL内金属微粒对表面电荷积聚影响的COMSOL®三维仿真研究 - new

倪潇茹 [1], 常帅 [1], 王志远 [1], 王靖瑞 [1], 于万水 [1],
[1] 华北电力大学

以SF6或SF6/N2混合气体为绝缘介质的GIL 具有大容量、高可靠性和环境友好等特点,而GIL中存在的金属微粒污染问题是提高设备绝缘强度研究中的关键技术难题。在GIL中,金属微粒引起的电场畸变会带来一系列绝缘问题,这些问题需要进行深入研究。针对直流GIL中金属微粒污染问题,本文研究其对绝缘子表面电荷积聚的影响。充分考虑附着导电微粒的情况,建立了可以灵活设置微粒与绝缘子相对位置的三维模型,利用COMSOL®软件的AC/DC模块对三维空间中绝缘子下绝缘子形状及表面附着微粒的不同粘附形态对表面电荷积聚的影响进行了求解分析。基于麦克斯韦方程组理论,我们首先对绝缘子表面电荷的积聚情况进行分析。然后纳入微粒污染以及气体侧微观尺度空间离子的产生、复合、迁移和扩散等作用,进一步建立了微粒污染情况下包含气体侧微观机制的绝缘子表面电荷积聚模型。 仿真研究显示,不同底角的绝缘子表面电荷均呈带状分布 ...

干式变压器电磁振动噪声的优化控制分析 - new

王斌 [1], 沙瑞 [1], 韩天衡 [1],
[1] 天津工业大学,天津,中国

干式变压器作为城区供电的重要电力设备,其连续运行时的振动噪声问题已成为制约其发展和应用的瓶颈,铁心的振动噪声不仅会对人们的生活环境造成污染,而且会降低设备的可靠性。由于该问题涉及电磁-机械-声多物理场耦合,铁心振动噪声的准确计算是研究此问题的关键。为此本文基于硅钢片磁特性的测量数据,并考虑铁心磁致伸缩效应,采用COMSOL Multiphysics多物理场仿真软件,通过AC/DC模块、声-固耦合模块对变压器铁心的应力、声压级分布进行研究,并提出优化控制方法。首先进行场路耦合计算,得到铁心磁场分布及应力分布,最后基于振动位移计算变压器的噪声情况。本研究有利于干式变压器在设计阶段评估本体振动噪声水平以及选择合适的工作磁通。 Reference [1] L. Lahn, C.Wang, A. Allwardt, T. Belgrand, and J. Blaszkowski, ...

基于 COMSOL Multiphysics 的水中等离子电弧放电的分析 - new

Yiyi Zhan [1], 唐文虎 [2],
[1] 广州航海学院
[2] 华南理工大学

在过去的二三十年中,液体燃烧电弧被用来制造纳米碳结构。该方法利用电弧空间中存在的碳蒸气作为电极腐蚀的结果,在存在高温梯度的区域迅速冷却时形成碳纳米管和富勒烯。碳结构的形成速率和结构取决于等离子体环境和形成机制两个方面。目前的研究工作,等离子体环境的形成和从电极表面的碳蒸气的传输是用二维电弧模型计算研究的。利用流动气液界面的传热来确定水的蒸发速率,考虑到电弧辐射对水蒸发的贡献以及碳和水蒸气之间的化学反应。此项研究使用COMSOL Multiphysics等离子体模块及传热模块。

基于环形馈线的77 GHz毫米波微带天线 - new

浦实 [1], 杨世佳 [1], 杨朝伟 [1],
[1] 武汉理工大学、武汉、湖北、中国

近年来,行驶车辆数量和平均驾驶时间都呈现剧增趋势,无人驾驶/辅助驾驶成为了竞相追捧的未来科技。汽车防撞毫米波雷达作为无人驾驶/辅助驾驶的关键技术,将得到广泛应用。未来可用于汽车防撞毫米波雷达的目标频段有24 GHz、28 GHz、60 GHz以及77 GHz等,其中77 GHz可拥有230 m的较长探测距离。本文提出一种基于环形馈线的77 GHz毫米波微带天线,包括4个结构完全相同的天线单元和环形馈线,其中4个天线单元均匀分布在环形馈线的圆周上,并指向环形馈线的圆心;每个天线单元包括3个通过微带线连接的贴片,每个天线单元通过微带线与环形馈线连接。利用这种结构,能够方便天线单元组成阵列,并实现整体结构的阻抗匹配设计,由于其中的简单结构单元均朝向内侧圆心,达到了节省空间的效果,使得天线整体结构更为紧凑。本文工作是利用COMSOL Multiphysics®软件RF模块进行设计的 ...

Numerical simulation of micro galvanic corrosion induced by intermetallic particle in Al alloys - new

Ying Jin [1], Litao Yin [2], Christofer Leygraf [3], Jinshan Pan [4],
[1] National Centre for Material Service Safety, University of Science & Technology Beijing, 100083 Beijing, China
[2] 1National Centre for Material Service Safety, University of Science & Technology Beijing, 100083 Beijing, China 2Div. Surface & Corrosion Science, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden
[3] 2Div. Surface & Corrosion Science, Dept. of Chemistry, School of Chemical Science and Engineering, KTH Royal Institute of Technology, Drottning Kristinas väg. 51, SE-100 44 Stockholm, Sweden
[4] Div. Surface & Corrosion Science, Dept. of Chemistry, School of Chemical Science and Engineering, KTH Royal Institute of Technology, Drottning Kristinas väg. 51, SE-100 44 Stockholm, Sweden

Intermetallic particles (IMPs) in Al alloys play an important role in localized corrosion processes, and largely affect the service safety and reliability of the alloys. However, most of the experimental methods used so far only probe active corrosion sites on a projected two-dimensional surface, with no detailed information about how localized corrosion develops and how the local chemical ...

Growth and Remodelling of Intracranial Saccular Aneurysms

A. Di Carlo[1], V. Sansalone[2], A. Tatone[3], and V. Varano[1]
[1]Modelling and Simulation Lab, Università Roma Tre, Roma, Italy
[2]Laboratoire de Mécanique Physique, Université Paris Est, Paris, France
[3]DISAT, Università degli Studi dell’Aquila, L'Aquila, Italy

We present a mechanical model a growing spherical shell suitable for predicting the evolution of a Saccular Cerebral Artery Aneurysms (SCAA). It relies basically on the Kröner-Lee decomposition, used to describe the interplay between the current and the relaxed configuration of body elements. Rupture or stabilization of a SCAA are the end effect of a number of biological mechanisms, still poorly ...

Thermal Analysis of Electrorefiner for Engineering Scale Pyroprocessing Studies

S. Agarwal, S.P. Ruhela, V. Mente, M.G. Hemanath, B. Murlidhran, V.S. Kumar, C.P. Reddy, G. Ravisankar, B.K. Sharma, K. Nagarajan, C.A. Babu, and P. Kalyanasundaram
Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu, India

Pyrochemical process based on molten salt electrorefining is ideally suited for reprocessing spent metallic fuels from Fast Breeder Reactors. In this work, a heat transfer analysis of the Electrorefiner cell was conducted to develop a basic tool for designing of the engineering–scale Electrorefiner. The focus of this work is to find out steady state temperature profiles of cover gas and molten ...

Coupled Hydrochemical Modeling for the Optimal Design of an In-situ Redox Experiment

P. Trinchero[1], J. Molinero[1], G. Román-Ross[1], A. Nardi[1], L.M. De Vries[1], T. Karvonen[2], P. Pitkänen[3]
[1]Amphos 21, Barcelona, Spain
[2]WaterHope, Helsinki, Finland
[3]Posiva, Eurajoki, Finland

In this work, we present a number of scoping calculations that have been carried out to design an in-situ redox experiment (Figure 1) focused on assessing potential changes in the pH and redox conditions and in the buffering capacity of the Olkiluoto bedrock (i.e. the site for the Finnish spent fuel repository). A characteristic of these models lies in the need to integrate prior information, ...