Articles techniques et présentations

前期研究中，我们设计了基于准同轴结构的微波等离子体无极灯 [1]。该结构以激发后的等离子体作为同轴内导体，法拉第笼作为外导体。仿真结果显示，电磁波在等离子体 - 金属构成的准同轴波导中传播时，同步被等离子体吸收并形成驻波；实验中，激发后的无极灯呈现亮 - 灭周期性特征，这与仿真所得电子密度分布特性高度一致。​ 基于上述研究基础，结合激发后等离子体具备高电导率、可作为同轴内导体的特性，我们进一步提出新设计，一种用于在放电管中产生长等离子体源的装置。该装置采用矩形波导与同轴波导组合结构，仍以高电导率的激发后等离子体为同轴内导体，外导体则由金属壁构成。对 Ar ... En savoir plus

电声产品的仿真包括电磁仿真、力学仿真、声学仿真，逐步拆解设计部件电磁设计最佳方案，悬挂系统对称性最佳方案，声学产品效果最佳方案，随着智能电声产品越来越小型化、集成化、多功能化，借助多物理场分析的场合越来越多，Comsol也可实现耳塞或耳垫的物理降噪仿真、耳机充电仓的磁吸力效果仿真、多单元耳机的声学效果集成仿真等，借助Comsol仿真可以有效辅助设计、缩短电声产品的开发周期。 En savoir plus

电子枪中加速电极的形状参数是影响电子枪性能的关键参数之一，其影响主要通过改变轴上电势分布实现，本研究建立了电子枪加速极的静电仿真简化模型，以加速极形状参数为变量、轴上电势曲线为目标进行参数化扫描，可以得到预设条件下的加速极厚度、孔径、间距等参数的影响趋势。该模型可用于电子枪加速电极的形状参数优化，导入具体电子枪几何模型后可以寻找加速极几何参数的局部最优解。 En savoir plus

磁性纳米线中的磁畴壁 (domain wall) 系统因兼具基础研究价值与应用潜力而备受关注。在窄而薄的纳米线中，横向磁畴壁(transverse domain wall)是最基本的磁畴壁类型。 存在两种截然不同的磁畴壁相互作用机制：首先，静磁相互作用会诱发长程吸引或排斥效应——等效而言，每个磁畴壁携带有效磁荷，介导着类库仑长程相互作用；其次，交换相互作用会在相邻畴壁间产生短程的吸引或排斥力，这实质上是一种拓扑相互作用。按照磁畴壁携带的等效磁荷的符号以及其拓扑手性，共有四种横向磁畴壁，分别记为R+,R-,L+,L-。 对于单根纳米线中的两个磁畴壁 ... En savoir plus

The paper reports on an electromagnetic field study of a 765 kV switchyard. The study is performed using COMSOL Multiphysics® software. The study involves geometric modelling, finite element analysis, and numerical solution of the linearized equations. For the system studied, it was ... En savoir plus

We present the utilization RF module of COMSOL Multiphysics® for understanding three different types of wave guidance mechanisms in photonic crystal fibers (PCFs), like modified total internal reflection, Bragg’s reflection and resonant trapping of defect mode at Dirac frequency. ... En savoir plus

Electric, magnetic and electromagnetic (em) methods are widely used to monitor active volcanoes. A review of such applications is presented in Johnston (cit). Em signals were recorded in correspondence of numerous volcanic eruptions, for example in the case of the Mt. Unzen in Giapppone, ... En savoir plus

Examples of Electromagnetic processes are presented: (1) cold crucible, (2) electromagnetic pump, (3) DC electromagnetic brake. A combined approach by using multiphysics modeling with Comsol and experimental validation is used in order to give some guidelines for process improvement and ... En savoir plus

Electromagnetic shielding design is usually approached referring to nominal values of the main parameters. This could lead to malfunctioning devices and its performance differ widely from what was really aimed at or, worse, the final design product could even be physically unrealizable. ... En savoir plus

DEMETER is a magnetic field replicator. This system is designed to deceive anti tank mines. Numerical simulation (using COMSOL Multiphysics® software) allows to indicate DEMETER's performance in various environment and various configurations. The study of the magnetic field provide also ... En savoir plus