Analytical theory of the probability distribution function of structure formation
Analytical theory of the probability distribution function of structure formation
复制标题
结构形成概率分布函数的解析理论
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
Eun
中科院分区：
文献类型：
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作者：
Johan Anderson;Eun
通过结合离子温度梯度 (ITG) 湍流中剪切流的影响，计算了带状流结构形成的概率分布函数 (PDF) 尾部和动量通量的 PDF 尾部。双极涡旋孤子（modon）被假定为负责驱动 PDF 尾部的突发和间歇事件的相干结构。研究发现，ITG 湍流中产生的纬向流比长谷川-美马湍流更强，并且离边际稳定更远。这表明，尽管 ITG 湍流具有更高水平的热通量，但它也更有可能产生更强的纬向流，从而形成自我调节系统。研究还表明，剪切流可以显着减少雷诺应力和结构形成的 PDF 尾部。
The probability distribution function (PDF) tails of the zonal flow structure formation and the PDF tails of momentum flux are computed by incorporating the effect of a shear flow in ion-temperature-gradient (ITG) turbulence. The bipolar vortex soliton (modon) is assumed to be the coherent structure responsible for bursty and intermittent events driving the PDF tails. It is found that stronger zonal flows are generated in ITG turbulence than Hasegawa–Mima turbulence, as well as further from marginal stability. This suggests that although ITG turbulence has a higher level of heat flux, it also more likely generates stronger zonal flows, leading to a self-regulating system. It is also shown that shear flows can significantly reduce the PDF tails of Reynolds stress and structure formation.