Kelvin:Helmholtz Instability at the magnetopause: Solution for compressible plasmas
Kelvin:Helmholtz Instability at the magnetopause: Solution for compressible plasmas
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DOI：
10.1029/ja088ia02p00841
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发表时间：
1983-02
影响因子：
--
通讯作者：
Z. Pu;M. Kivelson
中科院分区：
文献类型：
--
作者：
Z. Pu;M. Kivelson
在线性磁流体近似下，重新研究了可压缩等离子体切向间断的Kelvin-Helmholtz（K-H）不稳定性。对于固定的等离子体条件，两种不同类型的表面波（标记为F为快，S为慢）可以同时存在，具有不同的切向波矢量k/sub t/。界面两侧等离子体的相对流速U在一定范围内才能激发表面波。因此，不稳定性需要U/sub c/m或大约。=U/sub i/，但慢波增长率与μ/sub F/和μ/sub i/相比都很小。因此，等离子体的可压缩性是相对无效的减少表面波增长的临界速度低于不可压缩等离子体。
The Kelvin-Helmholtz (K-H) instability of a tangential discontinuity in a compressible plasma is reexamined in the linear magnetohydrodynamic (MHD) approximation. For fixed plasma conditions, two different kinds of surface waves (labeled F for fast and S for slow) may exist simultaneously with different tangential wave vectors k/sub t/. The surface waves can be excited only for a limited range of U, the relative flow speed of the plasmas on the two sides of the interface. Thus the instability requires U/sub c/m or approx. =U/sub i/, but the slow wave growth rate is small in comparison with both epsilon/sub F/ and epsilon/sub i/. Consequently, plasma compressibility is relatively ineffective in reducing the critical velocity for surface wave growth below that for an incompressible plasma.