Nonlinear theory of resonant slow waves in dissipative layers
Nonlinear theory of resonant slow waves in dissipative layers
复制标题
耗散层谐振慢波的非线性理论
DOI：
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发表时间：
1997
期刊：
影响因子：
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通讯作者：
M. Goossens
中科院分区：
文献类型：
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作者：
M. Ruderman;J. V. Hollweg;M. Goossens
线性耗散磁流体力学（MHD）表明，在高雷诺数磁等离子体中，当驱动磁流体波的频率等于磁表面的局部阿尔芬频率或慢频率时，磁流体波表现出近共振行为。这种近共振行为仅限于包含共振磁表面的薄耗散层。虽然驱动的MHD波在离共振磁面较远的地方具有较小的振幅，但耗散层中的这种近共振行为可能导致线性理论的崩溃。本文讨论了驱动MHD波在慢波耗散层中的非线性行为。采用匹配渐近展开的方法，得到了耗散层内波动变量的非线性方程。Sakurai， Goossens和Hollweg [Sol. Phys. 133, 227(1991)]在线性共振MHD波理论中引入的连接公式概念被扩展到包括耗散中的非线性效应。
Linear dissipative magnetohydrodynamics (MHD) shows that driven MHD waves in magnetic plasmas with high Reynolds number exhibit a near resonant behaviour if the frequency of the wave becomes equal to the local Alfven or slow frequency of a magnetic surface. This near resonant behaviour is confined to a thin dissipative layer which embraces the resonant magnetic surface. Although the driven MHD waves have small amplitudes far away from the resonant magnetic surface, this near-resonant behaviour in the dissipative layer may cause a breakdown of linear theory. In the present paper we deal with the nonlinear behaviour of driven MHD waves in the slow wave dissipative layer. The method of matched asymptotic expansions is used to obtain the nonlinear equation for wave variables inside the dissipative layer. The concept of connection formulae introduced into the theory of linear resonant MHD waves by Sakurai, Goossens, and Hollweg [Sol. Phys. 133, 227 (1991)] is extended to include nonlinear effects in the dissip...