旋转天体力学流动 - Alfven 波的高效放大器
摘要
我们表明，螺旋剪切流可作为 Alfven 波的高效放大器。我们发现，即使流为纯喹注流（即无旋转时），Alfven 波也会通过瞬态、剪切诱导的代数放大过程得到放大。一系列沿流顺序发生的瞬态放大，可能导致这些波的级联放大。然而，当流为旋转或螺旋流（即对等离子体运动施加某种旋转）时，Alfven 波将受到新的、更强大的剪切不稳定性的影响。在这种情况下， Depending on the type of differential rotation, both usual and parametric instabilities may appear. We claim that these phenomena may lead to the generation of large amplitude Alfven waves and the mechanism may account for the appearance of such waves in the solar atmosphere, in accretion-ejecion flows and in accretion columns. These processes may also serve as an important initial (linear and nonmodal) phase in the ultimate subcritical transition to MHD Alfvenic turbulence in various kinds of astrophysical shear flows.
引用
@article{arxiv.astro-ph/0212132,
title = {Swirling astrophysical flows - efficient amplifiers of Alfven waves},
author = {Andria D. Rogava and Swadesh M. Mahajan and Gianluigi Bodo and Silvano Massaglia},
journal= {arXiv preprint arXiv:astro-ph/0212132},
year = {2009}
}
备注
12 pages, 11 figures, accepted for publication (25-11-02) in Astronomy and Astrophysics