On the Nonlinear Evolution of Magnetohydrodynamic Kelvin-Helmholtz Instabilities
On the Nonlinear Evolution of Magnetohydrodynamic Kelvin-Helmholtz Instabilities
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DOI：
10.1086/176691
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发表时间：
1996
期刊：
影响因子：
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通讯作者：
A. Malagoli;G. Bodo;R. Rosner
中科院分区：
文献类型：
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作者：
A. Malagoli;G. Bodo;R. Rosner
我们研究的物理行为的Kelvin-Helmholtz（KH）不稳定性的非线性制度在一个简单的导电剪切流中的磁场的存在下，基于使用的理想磁流体运动方程的数值模拟在二维。流动的特点是由三个主要的控制参数：马赫数{ital M}的剪切流，比{alpha}的Alfv{acute e}n速度的声速，和有效的扩散率，我们调查这些参数如何影响的演变和饱和的不稳定性。我们研究的关键结果是，即使是相对较小的磁场（即，小的均分强度相比）影响的方式KH不稳定性饱和相对于纯流体动力的情况。如果磁场强度不足以完全抑制KH不稳定性，那么磁场本身仍然可以介导湍流衰减以及能量和质量在层间的扩散。我们提出了一个详细的研究，这个过程的各个阶段，我们简单的剪切层配置。美国天文学会（American Astronomical Society）
We investigate the physical behavior in the nonlinear regime of Kelvin-Helmholtz (KH) instabilities in a simple conducting shear flow in the presence of magnetic fields, based upon the use of numerical simulations of the ideal magnetofluid equations of motion in two dimensions. The flow is characterized by three principal control parameters: the Mach number {ital M} of the shear flow, the ratio {alpha} of the Alfv{acute e}n speed to the sound speed, and the effective diffusivity; we investigate how these parameters affect the evolution and saturation of the instability. The key result of our study is that even relatively small magnetic fields (i.e., small compared to the equipartition intensity) affect the way the KH instability saturates with respect to the purely hydrodynamic case. If the magnetic field intensity is not sufficiently strong to suppress the KH instability entirely, then the field itself can still mediate the turbulent decay and diffusion of energy and mass across the layer. We present a detailed study of the various phases of this process for our simple shear layer configuration. {copyright} {ital 1996 The American Astronomical Society.}