E x B Shear Flows and Electromagnetic Gyrofluid Turbulence
E x B Shear Flows and Electromagnetic Gyrofluid Turbulence
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E x B 剪切流和电磁陀螺流体湍流
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发表时间：
1999
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通讯作者：
B. Scott
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文献类型：
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作者：
B. Scott
采用电子和离子平等的陀螺流体方程对低频托克马克边缘湍流进行了数值模拟。电子是电磁的，任意强的有限回旋半径效应包括离子。计算是在一个全球一致的截断通量表面几何所产生的理想托卡马克平衡。湍流是类似的流体模型中的陡梯度制度，其中的电子渡越频率是可比的湍流。非线性漂移波不稳定性是由E×B自平流引起的，并且对于二维和三维模式是相似的。对于感兴趣的参数范围，湍流总是具有漂移波模式特征，除非达到理想的气球阈值。湍流与E×B剪切流强烈相互作用，但其本身不会将流剪切建立到显著水平。另一方面，一个强加的剪切层所产生的新古典平衡的边缘…
Low frequency tokamak edge turbulence is modelled numerically using gyrofluid equations for electrons and ions on an equal footing. The electrons are electromagnetic, and arbitrarily strong finite gyroradius effects are included for the ions. Computations are in a globally consistent truncation of flux surface geometry arising from ideal tokamak equilibria. The turbulence is similar to that in the fluid model in steep gradient regimes, for which the electron transit frequency is comparable to that of the turbulence. The nonlinear drift wave instability is shown to be caused by E×B self-advection, and is similar for both two-and three-dimensional models. The turbulence always has drift wave mode character for the parameter regime of interest, except when the ideal ballooning threshold is reached. Turbulence interacts strongly with E×B shear flows, but does not build the flow shear to significant levels by itself. On the other hand, an imposed shear layer arising from the neoclassical equilibrium of the edg...