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arXiv 1607.07579physics.plasm-ph
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强静电场turbulence中非线性动量输运驱动的极向旋转

Poloidal rotation driven by nonlinear momentum transport in strong electrostatic turbulence

Lu Wang, Tiliang Wen, P. H. Diamond

摘要:

实际上,现有的关于湍流极向动量输运的理论工作都是基于准线性理论。非线性极向动量通量- $\langle \tilde{v}_r \tilde{n} \tilde{v}_θ \rangle$被普遍忽略。然而,在相对脉动幅度不再小的强湍流区,准线性理论是无效的。这在至关重要的等离子体边缘是正确的。本文利用Hasegawa-Mima方程计算了强静电湍流中的非线性极向动量通量$ \langle \tilde{v}_r \tilde{n} \tilde{v}_θ \rangle $,并与准线性极向雷诺应力进行了比较。非线性极向动量通量的一个新性质是涨落谱的对称性破缺是不必要的。这与准线性的等效应力有本质的不同。此外,比较表明,极向旋转驱动的径向梯度的非线性动量通量是可比的,从准线性雷诺力。强静电湍流中的非线性极向动量输运对于极向旋转驱动是不可忽略的,因此可能对输运势垒的形成具有重要意义。

英文摘要:

Virtually, all existing theoretical works on turbulent poloidal momentum transport are based on quasilinear theory. Nonlinear poloidal momentum flux - $\langle \tilde{v}_r \tilde{n} \tilde{v}_θ \rangle$ is universally neglected. However, in the strong turbulence regime where relative fluctuation amplitude is no longer small, quasilinear theory is invalid. This is true at the all-important plasma edge. In this work, nonlinear poloidal momentum flux $ \langle \tilde{v}_r \tilde{n} \tilde{v}_θ \rangle $ in strong electrostatic turbulence is calculated using Hasegawa-Mima equation, and is compared with quasilinear poloidal Reynolds stress. A novel property is that symmetry breaking in fluctuation spectrum is not necessary for a nonlinear poloidal momentum flux. This is fundamentally different from the quasilinear Reynold stress. Furthermore, the comparison implies that the poloidal rotation drive from the radial gradient of nonlinear momentum flux is comparable to that from the quasilinear Reynolds force. Nonlinear poloidal momentum transport in strong electrostatic turbulence is thus not negligible for poloidal rotation drive, and so may be significant to transport barrier formation.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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