Three-dimensional simulations of the parallel velocity shear instability
Three-dimensional simulations of the parallel velocity shear instability
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DOI：
10.1063/1.872090
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发表时间：
1997-02
影响因子：
2.2
通讯作者：
D. McCarthy;A. E. Booth;J. Drake;P. Guzdar
中科院分区：
文献类型：
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作者：
D. McCarthy;A. E. Booth;J. Drake;P. Guzdar
采用三维非线性流体模拟方法研究了均匀磁化平板中静电平行速度剪切不稳定性的非线性模结构和反常动量输运。在这个简化模型中，系统取决于两个无量纲参数α=2πqRρs/Lv 2和ρ=ρs/LV，α = 2 πqRρs/Lv 2是声波传播时间与波型线性增长时间的比值，ρ=ρs/LV是离子拉莫尔半径与平行速度剖面的径向尺度长度的比值。在ρ=0的极限下，模结构非线性演化到m=2/α，n=1的状态，其中m为极向模数，n为环向模数。对于所有的α，输运的值都是D ρscs/2。当ρ = 0时，系统表现出不同的饱和状态，对于所有α，系统演化为m=1和n=α/2。对于所有α，运输保持D <$ρscs/2。拉莫尔半径的影响是，这个三维系统类似于众所周知的二维逆叶栅。
The nonlinear mode structure and anomalous momentum transport of the electrostatic parallel velocity shear instability in a uniformly magnetized slab were studied using three-dimensional (3-D) nonlinear fluid simulations. Within this simplified model, the system depends upon two dimensionless parameters α=2πqRρs/Lv2, which is a ratio of the sound transit time to the linear growth time of the mode and ρ=ρs/LV, which is a ratio of the ion Larmor radius and the radial scale length of the parallel velocity profile. In the limit of ρ=0, the mode structure evolved nonlinearly to a state with m=2/α and n=1 for α 1 where m is the poloidal mode number and n is the toroidal mode number. The transport had a value of D∼ρscs/2 for all α. For ρ≠0 the system displayed a different saturated state, evolving to m=1 and n=α/2 for all α. The transport remained D∼ρscs/2 for all α. The effect of the Larmor radius is this 3-D system is similar to the well known inverse cascade in a two-dimensional in...