Magnetic instabilities in rapidly rotating spherical geometries I. from cylinders to spheres
Magnetic instabilities in rapidly rotating spherical geometries I. from cylinders to spheres
复制标题
DOI：
10.1080/03091929108219516
复制
发表时间：
1991
影响因子：
1.3
通讯作者：
D. Fearn;W. Weiglhofer
中科院分区：
文献类型：
--
作者：
D. Fearn;W. Weiglhofer
全非线性水磁发电机问题的求解是一项重要的数值工作。在继续努力的同时，对发电机过程各个方面的补充研究可以大大提高我们对所涉及机制的理解。在本研究中，研究了在环形磁场Bo(r,θ)l⊘和环形速度场Uo(r,θ)l⊘（其中（r,θ,⊘）为极坐标）存在下，导电流体在刚性电绝缘球形容器中的线性稳定性。该系统是地球流体核心的一个模型，它是快速旋转的，使用了磁转近似，并排除了热效应。为了简化数值分析，早期的研究采用了圆柱形几何。尽管柱形几何保留了基本的物理性质，但球形几何是更适合地球的模型。在这里，我们使用圆柱系统的结果作为更真实的指导方针。
Abstract The solution of the full nonlinear hydromagnetic dynamo problem is a major numerical undertaking. While efforts continue, supplementary studies into various aspects of the dynamo process can greatly improve our understanding of the mechanisms involved. In the present study, the linear stability of an electrically conducting fluid in a rigid, electrically insulating spherical container in the presence of a toroidal magnetic field Bo(r,θ)l⊘ and toroidal velocity field Uo(r,θ)l⊘, [where (r,θ,⊘) are polar coordinates] is investigated. The system, a model for the Earth's fluid core, is rapidly rotating, the magnetostrophic approximation is used and thermal effects are excluded. Earlier studies have adopted a cylindrical geometry in order to simplify the numerical analysis. Although the cylindrical geometry retains the fundamental physics, a spherical geometry is a more appropriate model for the Earth. Here, we use the results which have been found for cylindrical systems as guidelines for the more rea...