Boundary effects and propagating, magnetic fronts in disc dynamos
Boundary effects and propagating, magnetic fronts in disc dynamos
复制标题
盘式发电机中的边界效应和传播磁锋
DOI：
10.1080/03091929808203688
复制
发表时间：
1998
影响因子：
1.3
通讯作者：
D. Sokoloff
中科院分区：
文献类型：
--
作者：
D. Moss;A. Shukurov;D. Sokoloff
摘要：我们讨论了平均场发电机方程的薄盘渐近解的有效性和准确性，使用新的数值代码对嵌入式盘模型进行计算，在非均匀网格上具有高空间分辨率。我们证明，只要引入有效盘厚度的概念，传统线性渐近解（使用真空边界条件）与数值结果之间存在合理的一致性。这一结果在圆盘发电机模型中具有更普遍的意义，因为有必要重新定义具有真空边界条件的模型的发电机数，以便将它们应用于没有尖锐边界的现实圆盘。我们还考虑了盘中不同区域具有不同增长率的本征模之间竞争的影响。与快速增长的本征模相关的前沿通过圆盘传播并最终主导解决方案。在典型的银河条件下，锋面速度...
Abstract We discuss the validity and accuracy of thin-disc asymptotic solutions of the mean-field dynamo equations, using a new numerical code to perform calculations for embedded disc models, with high spatial resolution on a nonuniform grid. We show that there is reasonable agreement between conventional linear asymptotic solutions (using vacuum boundary conditions) and numerical results, provided that the concept of effective disc thickness is introduced. This result is of more general significance in the context of disc dynamo models, in that it is necessary to redefine the dynamo number of models with vacuum boundary conditions in order to apply them to realistic discs without sharp boundaries. We also consider the effects of competition between eigenmodes with different growth rates localized in different regions of the disc. A front associated with the faster growing eigenmode propagates through the disc and eventually dominates the solution. Under typical galactic conditions, the frontal velocity ...