Anisotropy of magnetohydrodynamic turbulence at low magnetic Reynolds number
Anisotropy of magnetohydrodynamic turbulence at low magnetic Reynolds number
复制标题
低磁雷诺数下磁流体动力湍流的各向异性
DOI：
10.1063/1.2140847
复制
发表时间：
2005
影响因子：
4.6
通讯作者：
B. Knaepen
中科院分区：
文献类型：
--
作者：
A. Vorobev;O. Zikanov;P. Davidson;B. Knaepen
磁流体动力学流动中的湍流波动在足够强的磁场作用下变得各向异性。我们研究这种现象的情况下，低磁雷诺数使用直接数值模拟和大涡模拟的强迫流动的周期性的盒子。一系列的模拟进行了不同强度的磁场，不同的雷诺数，和两种类型的强迫，其中之一是各向同性和其他仅限于二维流动模式。我们发现，速度各向异性（速度分量的相对振幅的差异）和速度梯度的各向异性主要由磁相互作用参数的值确定。雷诺数和强迫类型的影响要弱得多。我们还发现，各向异性的变化只有轻微的长度尺度。
Turbulent fluctuations in magnetohydrodynamic flows are known to become anisotropic under the action of a sufficiently strong magnetic field. We investigate this phenomenon in the case of low magnetic Reynolds number using direct numerical simulations and large eddy simulations of a forced flow in a periodic box. A series of simulations is performed with different strengths of the magnetic field, varying Reynolds number, and two types of forcing, one of which is isotropic and the other limited to two-dimensional flow modes. We find that both the velocity anisotropy (difference in the relative amplitude of the velocity components) and the anisotropy of the velocity gradients are predominantly determined by the value of the magnetic interaction parameter. The effects of the Reynolds number and the type of forcing are much weaker. We also find that the anisotropy varies only slightly with the length scale.