On spontaneous formation of current sheets: Untwisted magnetic fields
On spontaneous formation of current sheets: Untwisted magnetic fields
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关于电流片的自发形成：未扭曲的磁场
DOI：
10.1063/1.3496379
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发表时间：
2010
影响因子：
2.2
通讯作者：
P. Smolarkiewicz
中科院分区：
文献类型：
--
作者：
R. Bhattacharyya;B. Low;P. Smolarkiewicz
本文研究了在不可压缩粘性流体中电流片的自发形成，流体具有理想的导电性，由磁流体动力学Navier-Stokes方程控制。两个初始值问题的数值解的三维，周期性的，无扭曲的磁场演变，在冻结条件下的磁拓扑结构没有变化，在特征流体雷诺数的顺序为500，从一个非平衡初始状态与流体在休息。这种演化将磁自由能转化为动能，所有动能都被粘性耗散掉，这样磁场就进入了一个能量最小的静态平衡。的解决方案表明，作为冻结条件的结果，电流片必须形成在演化过程中，尽管几何简单的规定的初始字段。除了与磁中性点和场反转层有关的电流片外，其他不与磁中性点和场反转层有关的电流片也是如此。
This is a study of the spontaneous formation of electric current sheets in an incompressible viscous fluid with perfect electrical conductivity, governed by the magnetohydrodynamic Navier–Stokes equations. Numerical solutions to two initial value problems are presented for a three-dimensional, periodic, untwisted magnetic field evolving, with no change in magnetic topology under the frozen-in condition and at characteristic fluid Reynolds numbers of the order of 500, from a nonequilibrium initial state with the fluid at rest. The evolution converts magnetic free energy into kinetic energy to be all dissipated away by viscosity so that the field settles into a minimum-energy, static equilibrium. The solutions demonstrate that, as a consequence of the frozen-in condition, current sheets must form during the evolution despite the geometric simplicity of the prescribed initial fields. In addition to the current sheets associated with magnetic neutral points and field reversal layers, other sheets not associat...