Statistical theory of subcritically-excited strong turbulence in inhomogeneous plasmas. II
Statistical theory of subcritically-excited strong turbulence in inhomogeneous plasmas. II
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DOI：
10.1143/jpsj.68.2611
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发表时间：
1999-08-01
影响因子：
1.7
通讯作者：
Itoh, K
中科院分区：
文献类型：
--
作者：
Itoh, SI;Itoh, K
统计力学描述扩展到自持非均匀湍流，包括热波动的影响。在非均匀磁场存在下，揭示亚临界激发强湍流的交换模式被认为是集体模式，为测试模式制定了朗之万方程，其中与热涨落的相干相互作用被保留为碰撞阻力，非相干相互作用被认为是热噪声：相干非线性相互作用被保留为重正化湍流阻力，非相干相互作用被认为是随机自噪声。因此，热激发和湍流激发都包括在内。假设两种噪声统计上独立，得到稳态湍流状态的解，并对波动水平进行分析；去相关率，相关函数清楚地显示了热波动激发的模式与亚临界自激模式之间的联系。水平表示为非平衡参数（梯度）的非线性函数（具有滞后）。在梯度温度空间中获得相图。明确提出了远非平衡系统的扩展涨落耗散定理的应用，并提出了新的统计关系。
A statistical mechanics description is extended for a self-sustained inhomogeneous turbulence, including the effects of thermal fluctuations. Interchange mode in the presence of inhomogeneous magnetic field, which reveals a subcritically-excited strong turbulence, is considered as a collective mode, A Langevin equation is formulated for a test mode, in which the coherent interactions with thermal fluctuations are kept as a collisional drag and the incoherent ones are considered to be thermal noise: The coherent nonlinear interactions are kept as a renormalized turbulent drag, and the incoherent ones are considered to he a random self-noise. Both thermal and turbulent excitations are thus included. The solutions of stationary turbulent state are obtained, provided that both noises are statistically independent, The analysis for the fluctuation level; decorrelation rate, and the correlation functions clearly shows the connection between a mode which is excited by thermal fluctuations and the one being subcritically self-excited. The level is expressed as nonlinear functions (with hysteresis) of nonequilibrium parameter (gradient). A phase diagram is obtained in the gradient-temperature space. An application of the extended fluctuation-dissipation theorem for far non-equilibrium system is explicitly made and new statistical relations are presented.