Dynamics of turbulence spreading in magnetically confined plasmas -: art. no. 032303
Dynamics of turbulence spreading in magnetically confined plasmas -: art. no. 032303
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DOI：
10.1063/1.1853385
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发表时间：
2005-03-01
影响因子：
2.2
通讯作者：
Lin, Z
中科院分区：
文献类型：
--
作者：
Gürcan, ÖD;Diamond, PH;Lin, Z
提出了紊流扩散和非局部相互作用现象的动力学理论。基本模型采用Fokker-Planck理论推导，由波动动力学支持，k是类型闭包元素。在没有局部增长的情况下，该模型预测了湍流的次扩散扩散。随着非线性阻尼的局部增长和饱和，湍流强度锋的弹道传播成为可能。时间渐近锋面速度由局部增长和湍流扩散的几何平均值确定。当湍流达到局部饱和时，锋面前缘向前推进。研究表明，湍流可以跳过局部增长率剖面的间隙，穿透局部边缘或稳定区域。特别是，来自湍流边缘的显著波动能量很容易扩散到边缘稳定的核心，从而形成一个强湍流的中间区域。这表明，应该重新考虑核心和边缘之间的传统区别。(C) 2005美国物理研究所。
A dynamical theory of turbulence spreading and nonlocal interaction phenomena is presented. The basic model is derived using Fokker-Planck theory, and supported by wave-kinetic and K-is an element of type closures. In the absence of local growth, the model predicts subdiffusive spreading of turbulence. With local growth and saturation via nonlinear damping, ballistic propagation of turbulence intensity fronts is possible. The time asymptotic front speed is set by the geometric mean of local growth and turbulent diffusion. The leading edge of the front progresses as the turbulence comes to local saturation. Studies indicate that turbulence can jump gaps in the local growth rate profile and can penetrate locally marginal or stable regions. In particular, significant fluctuation energy from a turbulent edge can easily spread into the marginally stable core, thus creating an intermediate zone of strong turbulence. This suggests that the traditional distinction between core and edge should be reconsidered. (C) 2005 American Institute of Physics.