共查询到20条相似文献,搜索用时 109 毫秒
1.
非理想MHD效应与m=1内扭曲模本征方程 总被引:1,自引:1,他引:0
对非俘获粒子与俘获粒子分别采用流体和单粒子模型,推导了同时包含各种非理想MHD效应的m=1内扭曲模本征方程,这些效应包括有限电阻,反磁漂移,俘获离子引起的增大的极化漂移与横向粘滞,沿力线电子热导,反常电子横和粘滞,俘获离子香蕉轨道宽度及自举电流等效应,所得到的m=1内扭曲模本征方程,为研究不同情况下各种非理想MHD效应的相对重要性及可能以m=1内扭曲稳定性的影响,提供了一可靠的基础。 相似文献
2.
利用描述俘获粒子运动的四流体模型推导出包含俘获粒子效应,离子反磁漂移,有限电阻及反常电子粘滞效应的m=1的内扭曲模本征方程和色散关系,并在等离子体芯部存在与不存在的高能粒子的两种情况下,讨论了俘获粒子效应和各种耗散效应对内扭曲模的影响。 相似文献
3.
托卡马克理想磁流体不稳定性的统一描述 (I) 总被引:1,自引:0,他引:1
石秉仁 《核聚变与等离子体物理》2001,21(2):65-72
在与平衡磁面相联系的坐标系下,用剪切阿尔芬波近似给出了统一描述托卡马克等离子体理想磁流体线性运动的本征模方程。利用此方程,可以进一步给出大尺度扰动(扭曲模、低模数气球模、阿尔芬模)和小尺度扰动(高模数气球模、Mercier模)的本征模方程。本文详细讨论了小尺度扰动的本征模方程。 相似文献
4.
电阻性磁流体内扭曲模的离子粘滞性效应 总被引:1,自引:1,他引:0
通过进一步分析电阻性磁流体内扭曲模的频率和增长率与离子粘滞性的关系,证明离子粘滞性对电阻性磁流体内扭曲模的稳定作用与磁切量的大小密切相关。通常微扰方法得出的结论,即当离子粘滞率大于某一临界值时该模式被完全稳定,仅当磁剪切量非常小时才正确;当磁剪切变大时,离子 粘滞的稳定效应很快减弱。 相似文献
5.
环形轴对称等离子体的理想磁流体简正模方程 总被引:2,自引:2,他引:0
石秉仁 《核聚变与等离子体物理》1993,13(3):1-8
本文在环形轴对称正文坐标系中对理想磁流体运动方程进行了严格自洽的讨论,通过对压缩量·ξ项的分析,发现在ω~2《K_1~2C_~2及ω~2》K_1~2C_5~2的两种极限情况下,可以仅用两个标函数来描述全域性模的运动。对于托卡马克等离子体,可引入剪切阿尔芬近似,得到由一个标函数描述的本征运动方程,它类似于文献中常用的简化托卡马克方程,但有一些重要不同点。该方程可用于分析计算各种频段的磁流体线性运动(包括扭曲模、阿尔芬波、间隙模等)。 相似文献
6.
石秉仁 《核聚变与等离子体物理》2001,21(3):129-136
采用磁力线为直线的坐标系,进一步将托卡马克理想磁流体剪切阿尔芬运动方程展开,获得了描述低模数环形阿尔芬本征模(TAE和EAE)的方程。 相似文献
7.
反常输运与非线性自持磁岛的自洽分析 总被引:3,自引:3,他引:0
从沿磁力线的等离子体电流与粒子径向输运相关的新经典MHD型的广义欧姆定律出发,提出了分析反常输运与非线性自持磁岛的自洽理论模型,基于该模型导出了反常扩散系数及反常电子热导。结果表明,非线性磁岛链可由磁岛调制的反常输动维持,反过来又通过磁岛短路效应维持反常输运。 相似文献
8.
串级磁镜电子抗磁性漂移气球模 总被引:1,自引:1,他引:0
本文利用气球模本征方程,研究了轴对称串级磁镜中电子的抗磁性漂移对离子有限拉莫尔半径致稳气球模的影响,得到了不同电子温度温度情况下的气球模增长率及产生边缘不稳定性的临界β值,并讨论了相应的物理机制。 相似文献
9.
10.
用积分本征模方程研究了在托卡马克等离子体中包含全部动力学效应的动力剪切阿尔芬波模 (无论是否存在温度梯度). 引入了一个新的积分变量,将实平面的积分解析延拓到复平面. 这样可以同时研究增长模和阻尼模. 结果表明,在有离子温度梯度(ITG)的情况下,激发动 力剪切阿尔芬不稳定性所需的等离子体压强梯度比激发理想磁流体动力学气球模不稳定性的 阈值低得多,没有ITG时两者相同. 与动力无碰撞气球模结果不同,当有限ITG存在时,剪切 阿尔芬模存在第二稳定区.
关键词:
动力剪切阿尔芬模
磁流体气球模
阈值压强梯度 相似文献
11.
12.
13.
本文研究粘滞效应对非线性电阻撕裂模的影响。利用准环坐标将具有标量电阻率和粘滞系数的MHD方程简化为一组无量纲的非线性方程。并对这组方程采用二步交替隐式差分格式进行数值计算。结果给出了2/1模的演变过程对无量纲粘滞系数的依赖关系和电流密度的分布。发现粘滞效应对饱和磁岛宽度的修正大约为5%(此时R=10~(-5)),同时发现由于粘滞效应的引入导致电流分布在奇异面附近的涨落明显减小。 相似文献
14.
15.
A new one-dimensional transport code named TASK/TX, which is able to describe dynamic behavior of tokamak plasmas, has been developed. It solves simultaneously a set of flux-surface averaged equations composed of Maxwell’s equations, continuity equations, equations of motion, heat transport equations, fast-particle slowing-down equations and two-group neutral diffusion equations. The set of equations describes plasma rotations in both toroidal and poloidal directions through momentum transfer and evaluates the radial electric field self-consistently. The finite element method with a piecewise linear interpolation function is employed with a fine radial mesh near the plasma surface. The Streamline Upwind Petrov–Galerkin method is also used for robust calculation. We have confirmed that the neoclassical properties are well described by the poloidal neoclassical viscous force. The modification of density profile during neutral beam injection is presented. In the presence of ion orbit loss, the generation of the inward radial electric field and torque due to radial current is self-consistently calculated. 相似文献
16.
E. G. Sheikin 《Technical Physics》2011,56(8):1091-1099
An analytical solution is obtained for the system of magnetohydrodynamic (MHD) equations in a quasi-one-dimensional approximation
for flow regimes with a monotonic variation of the velocity along a MHD channel. The problem of optimal choice of the parameters
of an MHD generator for the given ratio of the areas of the outlet and inlet MHD channel cross sections is considered using
the resultant analytic solution. 相似文献
17.
V. P. Pastukhov 《JETP Letters》1998,67(11):940-946
A simplified system of MHD equations describing the nonlinear dynamics of a toroidal plasma in a high magnetic field is obtained by correct elimination of the fast magnetosonic oscillations. In contrast to earlier analogs (Kadomtsev-Pogutse, Strauss, and other equations), the symmetries and the corresponding conservation laws characteristic of the initial complete system of MHD equations are preserved in the system of equations obtained here. This makes it possible to use the system obtained here to analyze the dynamics of plasma with flow and to avoid error accumulation in the analysis of the long-time evolution of disturbances. 相似文献
18.
The linear eigenstate problem of generalized magnetohydrodynamics(MHD) equations in a cylindrical plasma is discussed. The effects of finite frequency and finite pressure perturbation lead to an important result: the resonant layer of the shear Alfven waves is not a singular layer. In this paper, the MHD equations are reduced to four differential equations of first order for perturbed quantities. An analytical dispersion relation for a homogeneous plasma cylinder is obtained. The K. Appert theory is a limiting case of our theory 相似文献
19.
本文舍去多方近似,从完整的MHD方程出发,对一个具有粘性,可压缩性,及自引力的旋转MHD系统给出变分原理和稳定性条件。 相似文献
20.
Voshall R. E. Wright R. J. Liebermann R. W. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1977,5(2):110-122
A closed-cycle MHD generator topping a steam bottoming plant is analyzed. The combined power plant involves three working fluids in three loops. The MHD loop is investigated more thoroughly since it is the least conventional of the three. Equations are developed to determine the geometric and thermodynamic variables throughout the MHD channel for inlet conditions of mass flow, temperature, pressure, and velocity. Limiting design parameters are output power, channel length, channel aspect ratio, Hall parameter, and interaction parameter. The basic closed-cycle MHD loop working fluid can consist of either argon or helium seeded with cesium. Both non-equilibrium ionization produced by the elevation of the electron temperature from joule heating of the plasma and thermal ionization are considered. Equations used to calculate the electrical conductivity and the elevation of electron temperatures are derived. These equations are coupled with the one-dimentional differential equations applicable to an MHD generator. The chief interest is in determining those MHD channel conditions which result in the most thermodynamically efficient MHD-steam plantcombination. Thus an overall heat balance forthe system is required. Equations are developed to calculate the gas properties at the various stations of the closed loop and to determine the overall efficiency of the cycle. A rather flexible computer program written in Fortran is used to solve the MHD generator equations and to make the overall heat balance. Some typical results presented demonstrate the feasibility and adaptability of the analysis for optimizing the thermal efficiency and the sensitivity of thermal efficiency to various parameters. 相似文献