Articles techniques et présentations

电磁辐射对燃油危害是加油站、炼油厂、油气基地等大型设施禁用手机和其他无线通讯设备的重要原因。不同于静电对燃油蒸气的危害，本文的研究重点在于分析不同频率下的射频放电击穿特性。基于射频等离子体鞘层模型，通过多物理场仿真，分析了12M~300MHz频率下的氩气射频放电过程。仿真结果表明，当激励频率大于雪崩击穿临界频率时，两侧极板附近会形成随激励周期变化的鞘层区，中心区域为准电中性的等离子体区。同时，当激励频率远小于等离子体频率时，鞘层会促进极板附近的γ电离过程；随着频率增大，鞘层特性会逐渐退化，而中心区域的α电离过程会增强。此外，放电特性曲线表明，频率越高，板间放电电压越小 ... En savoir plus

Thermal ablation driven by an acoustic heat source has tremendous potential for the treatment of diseased tissue. In many applications, such as treating tumors in the liver, bulk removal of tissue is required, and thermal ablation can reliably cause necrosis for a relatively large tissue ... En savoir plus

Perfectly matched layers (PML) are an efficient alternative for emulating the Sommerfeld radiation condition in the numerical solution of wave radiation and scattering problems. The key ingredient of the PML formulation is the complex scaling function, which controls the anisotropic ... En savoir plus

Efforts involving simulation of  transmission line networks necessitate the accurate values of the parameters of the lines. In this paper, as an attempt in estimating such parameters, the parameters of high voltage asymmetric power lines are calculated. In the process of estimation, the ... En savoir plus

The majority of electrical machines are designed to produce the rotary motion, there by exploiting the blessing of circularity which man has enjoyed since the discovery of the wheel. Electromagnetic forces may also be employed to produce the linear motion resulting in linear motion ... En savoir plus

Industrial microwave ovens are widely used in agri-food and chemical applications. Resonant cavities are used to speed up chemical reactions and have the advantage to be small sized and efficient in terms of microwave distribution. These multimode cavities are considered as batch ovens ... En savoir plus

Because of its high enthalpy of combustion, aluminum has been added to energetic materials. In this paper, a two dimension thermal model is developed and assessed to describe the interrelated processes of Aluminum particle oxidation by using the software COMSOL Multiphysics. The thermal ... En savoir plus

High power Lower-Hybrid RF waves injected at in a Tokamak plasma can strongly modify the edge plasma. This is caused by ponderomotive forces pushing charged particles in an inhomogeneous oscillating electromagnetic field towards weaker field areas. On the Alcator C-Mod Tokamak, edge ... En savoir plus

Microwave imaging has been recently proposed as a potentially useful screening technique for breast cancer. This method detects abnormalities in the tissue based on permittivity difference between breast normal and malignant tissue. In this method breast is illuminated by high frequency ... En savoir plus

The classical optimization method has been applied to many design problems for electromagnetic systems. One of its major difficulties is related to meshing problems arising from shape modifications. In order to circumvent these kinds of technical difficulties with moving mesh problems, ... En savoir plus