共查询到15条相似文献,搜索用时 109 毫秒
1.
2.
3.
4.
5.
采用等效媒质处理方法来研究有限引导磁场下沿纵向运动的相对论环形电子注.首先建立运动坐标系以电子注纵向速度匀速运动,在运动坐标系中电子注可以被考虑成静止的磁化等离子体,再通过四维空间的洛伦兹变换得到电子注在静止的实验室坐标系下可以被等效为双各向异性媒质,其不仅具有张量形式的电导率和磁导率,还具有手征特性.在此基础上同时考虑了由于电子注表面波动所引起的表面电流密度.采用该方法研究了有限引导磁场下圆柱波导中沿纵向运动的相对论环形电子注,推导出该模型的色散方程,并进行了数值计算.计算结果表明该研究方法能够得到更准
关键词:
相对论环形电子注
磁化等离子体
色散特性 相似文献
6.
提出了一种用于辐射高功率微波的各向异性磁化等离子体通道天线(AMPCA),阐述了该天线的具体实现方法,给出了其工作原理,建立了AMPCA的电磁模型。推导了广义柱坐标系下各向异性磁化等离子体中纵向场满足的波动方程,并给出了纵向场与横向场的关系,利用边界条件导出了AMPCA传播模式的特征方程,并在极限条件下,将结果与已有文献进行对比,验证了所推导结果的正确性和有效性。数值计算了AMPCA传播模式的色散曲线。 相似文献
7.
分析了电磁波以任意角度入射到有限磁场中的激光等离子体通道天线(LPCA)时的电磁散射特性。根据LPCA的工作原理建立了其电磁分析模型,推导出广义柱坐标系下各向异性磁化等离子体中纵向分量所满足的波动方程和纵向场与横向场的关系,得到LPCA和周围媒质中的电磁场,利用边界切向电磁场连续,得出了散射系数方程。通过计算实例,将结果与文献结果比较,吻合较好。该研究结果预期可应用于高功率微波武器系统的研究。 相似文献
8.
分析了有限磁场中激光等离子体通道周围为有耗气体介质时激光引导电磁脉冲传播的一般模式的传播特性,建立了有限磁场中激光等离子体通道引导电磁脉冲的几何模型,导出了广义柱坐标系下各向异性介质中纵向场所满足的波动方程及纵向场与横向场的关系。利用边界条件给出了有限磁场中激光引导电磁脉冲传播模式的严格特征方程,重点讨论了传播常数随等离子体参数、周围介质参数和外加磁场的变化。结果表明,有限磁场中激光引导电磁脉冲的传播特性比无磁场或外加无穷大磁场时更具有可控性。 相似文献
9.
10.
本文从描述理想等离子体运动的线性化磁流体方程出发,导出了压缩量▽·ξ的一个表示式。一般情况下,它由两部分组成:第一部分与纵向惯性运动有关,第二部分与载等离子体力管的均匀运动(膨胀与压缩)有关。对于等离子体柱,我们讨论了几种可以将含有压缩量项的运动方程作某些简化的情形。利用这些结果,导出和分析了描述具有均匀分布电流的等离子体柱运动的色散关系。 相似文献
11.
Jin-Ping Xu 《International Journal of Infrared and Millimeter Waves》1996,17(1):193-203
A chiroferrite is made from chiral objects immersed in a magnetically biased ferrite. A waveguide including a chiroferrite is anticipated to possess some novel features due to the presence of chirality in combination with anisotropy. In this paper, the propagation characteristics of a circular metal waveguide filled with a chiroferrite medium are investigated by an analytical procedure. The equations of relations between the transverse components and the longitudinal ones of electromagnetic fields in general chiroferrite waveguides are derived in a cylindrical coordinate system. The coupled wave equations for the longitudinal electric and magnetic fields are decoupled into two Helmholtz equations which are then solved analytically. The characteristic equation is formulated for the circular chiroferrite waveguide. Propagation constants varying with the structural and material parameters have been calculated for several lower chiral modes. A number of interesting features have been revealed by the numerical results. 相似文献
12.
H.S. TÜRKMEN 《Journal of sound and vibration》2002,249(4):663-678
The results from a theoretical and experimental investigation of the dynamic response of cylindrically curved laminated composite shells subjected to normal blast loading are presented. The dynamic equations of motion for cylindrical laminated shells are derived using the assumptions of Love's theory of thin elastic shells. Kinematically admissible displacement functions are chosen to represent the motion of the clamped cylindrical shell and the governing equations are obtained in the time domain using the Galerkin method. The time-dependent equations of the cylindrically curved laminated shell are then solved by the Runge-Kutta-Verner method. Finite element modelling and analysis for the blast-loaded cylindrical shell are also presented. Experimental results for cylindrically curved laminated composite shells with clamped edges and subjected to blast loading are presented. The blast pressure and strain measurements are performed on the shell panels. The strain response frequencies of the clamped cylindrical shells subjected to blast load are obtained using the fast Fourier transformation technique. In addition, the effects of material properties on the dynamic behaviour are examined. The strain-time history curves show agreement between the experimental and analysis results in the longitudinal direction of the cylindrical panels. However, there is a discrepancy between the experimental and analysis results in the circumferential direction of the cylindrical panels. A good prediction is obtained for the response frequency of the cylindrical shell panels. 相似文献
13.
给出横向各向同性介质中SH波的标量波动方程,并通过简单的坐标变换,将其化为标准的Helmholtz方程.建立了求解散射问题的积分方程,利用边界单元方法数值计算了横向各向同性固体中圆柱状空洞及刚性散射体对SH波的散射场分布。重点分析了各向异性对空洞散射体散射场指向性的影响. 相似文献
14.
15.
本文从Vlasov-Maxwell方程组出发,保留高频场到四级项,导得了纵、横波大幅高频场与低频振荡粒子拍频作用的动力学方程组。结果表明,在空间一维情况下,对亚声波,高阶大幅高频场的存在使形成Soliton的有质动力凝聚作用削弱,而对超声波则更不存在Soliton解;在三维情况下,似乎使Caviton形成变慢。
关键词: 相似文献