Formation of magnetic flux tubes in cylindrical wedge geometry
Formation of magnetic flux tubes in cylindrical wedge geometry
复制标题
圆柱形楔形几何形状磁通管的形成
DOI：
10.1080/03091929.2011.643236
复制
发表时间：
2012
影响因子：
1.3
通讯作者：
Botha G
中科院分区：
文献类型：
--
作者：
Botha G
三维（3D） MHD数值模拟还不能令人信服地证明大型垂直磁通管的自发形成。轴对称圆柱体中的二维磁对流形成一个由环形对流环包围的中心磁通管。为了研究这类解在三维空间中的鲁棒性，在初始均匀垂直磁场条件下，对三维圆柱形楔中非线性电阻MHD方程进行了数值求解。结果表明，在较小的域半径范围内，二维结果可以被检索到。然而，对于较大的半径，中心轴失去了它的重要性，在这种情况下，许多对流细胞形成在数值域。磁通量在细胞之间被捕获，在那里流体汇聚，而聚集在中心轴的减少的磁通量被周围的对流侵蚀。
Three-dimensional (3D) MHD numerical simulations have not been able to demonstrate convincingly the spontaneous formation of large vertical flux tubes. Two-dimensional (2D) magnetoconvection in axisymmetric cylinders forms a central magnetic flux tube surrounded by annular convection rings. To study the robustness of this type of solution in three dimensions, the nonlinear resistive MHD equations are solved numerically in a 3D cylindrical wedge from an initially uniform vertical magnetic field. It is shown that the 2D result is retrieved for small domain radii. However, for larger radii the central axis loses its importance and in this case many convection cells form in the numerical domain. Magnetic flux is captured between cells where flow converges and the reduced amount of flux that congregates at the central axis is eroded by the surrounding convection.