Study of a drift wave-zonal mode system based on global electromagnetic Landau-fluid ITG simulation in toroidal plasmas
Study of a drift wave-zonal mode system based on global electromagnetic Landau-fluid ITG simulation in toroidal plasmas
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DOI：
10.1088/0029-5515/45/6/003
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发表时间：
2005-06
期刊：
影响因子：
3.3
通讯作者：
N. Miyato;J.Q. Li;Y. Kishimoto
中科院分区：
文献类型：
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作者：
N. Miyato;J.Q. Li;Y. Kishimoto
利用环面几何中的全局Landau流体程序，研究了电磁离子温度梯度(ITG)驱动的湍流纬向模系统。两种不同类型的纬向流，即在低Q(安全系数)区的定常纬向流和在高Q区的振荡纬向流，被称为测地线声学模式，在一个环面内同时被激发。定常流动有效地抑制了湍流的输运，而振荡流动由于其时变性而对湍流的影响较弱。因此，在纬向流基本稳定的低Q区，它们在湍流中占主导地位。另一方面，在纬向气流振荡的高Q区，湍流仍然活跃。
Using a global Landau-fluid code in toroidal geometry, an electromagnetic ion temperature gradient (ITG) driven turbulence–zonal mode system is investigated. Two different types of zonal flows, i.e. stationary zonal flows in a low q (safety factor) region and oscillatory ones in a high q region, which are called geodesic acoustic modes, are found to be simultaneously excited in a torus. The stationary flows efficiently suppress turbulent transport, while the oscillatory ones weakly affect the turbulence due to their time varying nature. Therefore, in the low q region where the zonal flows are almost stationary, they are dominant over the turbulence. On the other hand, the turbulence is still active in the high q region where the zonal flows are oscillatory.