Statistical analysis of the turbulent Reynolds stress and its link to the shear flow generation in a cylindrical laboratory plasma device
Statistical analysis of the turbulent Reynolds stress and its link to the shear flow generation in a cylindrical laboratory plasma device
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DOI：
10.1063/1.2985836
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发表时间：
2008-09
影响因子：
2.2
通讯作者：
Zheng Yan;J. Yu;C. Holland;Min Xu;S. Müller;G. Tynan
中科院分区：
文献类型：
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作者：
Zheng Yan;J. Yu;C. Holland;Min Xu;S. Müller;G. Tynan
研究了磁化等离子体柱中碰撞漂移湍流产生的湍流雷诺应力的统计特性，并讨论了湍流驱动剪切流生成的物理图。雷诺应力在最大密度梯度区域附近达到峰值，并由湍流幅度和湍流径向速度场和方位角速度场之间的交叉相位控制。湍流雷诺应力的振幅概率分布函数 (PDF) 是非高斯分布，并且在密度梯度最大值处呈正偏态。湍流离子饱和 (Isat) 电流 PDF 显示，突发 Isat 事件发生的区域与正偏非高斯雷诺应力 PDF 重合，这表明粒子传输的爆发似乎也与动量传输的爆发相关。在剪切层，密度涨落径向相关长度具有极小值（∼4–6mm∼0.5Cs∕Ωci，其中 Cs 是离子声速，Ωci ...
The statistical properties of the turbulent Reynolds stress arising from collisional drift turbulence in a magnetized plasma column are studied and a physical picture of turbulent driven shear flow generation is discussed. The Reynolds stress peaks near the maximal density gradient region, and is governed by the turbulence amplitude and cross-phase between the turbulent radial and azimuthal velocity fields. The amplitude probability distribution function (PDF) of the turbulent Reynolds stress is non-Gaussian and positively skewed at the density gradient maximum. The turbulent ion-saturation (Isat) current PDF shows that the region where the bursty Isat events are born coincides with the positively skewed non-Gaussian Reynolds stress PDF, which suggests that the bursts of particle transport appear to be associated with bursts of momentum transport as well. At the shear layer the density fluctuation radial correlation length has a strong minimum (∼4–6mm∼0.5Cs∕Ωci, where Cs is the ion acoustic speed and Ωci ...