On the self-heating phenomenon in nonmodal shear flow
On the self-heating phenomenon in nonmodal shear flow
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非模态剪切流中的自热现象
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
Zhong‐yuan Li
中科院分区：
文献类型：
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作者：
Jing;Yao Chen;Zhong‐yuan Li
本文研究了线性剪切流的非模态自热现象[A. D.罗伽瓦，天体物理学。空间科学293，189（2004）]的研究与初始激发Alfvenic扰动集中在决定加热过程的效率的因素。结果表明，为了得到有效的自加热过程，初始Alfven波必须至少部分地转变为快模。这是因为在三种类型的磁流体动力学模式中，只有快模式可以被剪切流显著放大。这要求沿切变的初始波数沿着为正，使得空间傅立叶谐波可以通过退化区域，并且还对等离子体参数β [β= CS 2 scinVA 2，其中CS（VA）是声音（Alfvenic）速度]施加约束。结果表明，自热函数随β的增大而单调减小，自热函数表示在某一时刻耗散的总能量。此外，为了获得有效的加热，粘性系数...
In this article, the nonmodal self-heating phenomenon of linear shear flow [A. D. Rogava, Astrophys. Space Sci. 293, 189 (2004)] is investigated with an initially excited Alfvenic perturbation focusing on the factors determining the efficiency of the heating process. It is found that to get an efficient self-heating process, the initial Alfven wave must be at least partially transformed into the fast mode. This is because only the fast mode, among the three types of magnetohydrodynamic modes, can get amplified significantly by the shear flow. This requires the initial wave number along the shear to be positive so that the Spatial Fourier Harmonics can pass through the degeneration region, and also puts constraints on the plasma parameter β [β=CS2∕VA2, where CS (VA) is the sound (Alfvenic) velocity]. It is shown that the self-heating function, which represents the total energy dissipated at a certain time, decreases monotonically with increasing β. In addition, to get efficient heating the viscous coeffici...