The Reynolds stress induced by weakly up-down asymmetric ion temperature gradient mode
The Reynolds stress induced by weakly up-down asymmetric ion temperature gradient mode
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DOI：
10.1063/1.4966241
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发表时间：
2016-10
影响因子：
2.2
通讯作者：
T. Xie;Y. Zhang;S. Mahajan;Z. Liu;Hongda He
中科院分区：
文献类型：
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作者：
T. Xie;Y. Zhang;S. Mahajan;Z. Liu;Hongda He
一个弱的上下不对称离子温度梯度（ITG）模式（形成在上下对称平衡），本地化的坏曲率区域，可能会占主导地位的非线性雷诺应力，因为它的增长率高于竞争模式：强烈的上下不对称模式，和其他模式的峰值（poloidally）远离外侧中平面。基于流体ITG模型，构造了二维傅立叶气球表示的参数化解析波函数，并利用有限差分法进行了数值验证。给出了弱和强上下非对称ITG模的极向雷诺应力的解析表达式。结果表明，这两种模式的极向应力可以解释为一个叠加的一个偶极子和偶极子结构。为了与实验进行比较，计算了五台机器上L型放电参数下的应力。分析实验室
A weakly up-down asymmetric ion temperature gradient (ITG) mode (formed in the up-down symmetric equilibrium), localized in the bad curvature region, may contribute dominantly to the nonlinear Reynolds stress because its growth rate is higher than the competing modes: the strongly up-down asymmetric modes, and other modes peaked (poloidally) away from the outboard mid-plane. Based on the fluid ITG model, the parameterized analytic wave function is constructed in the two dimensional (2D) Fourier-ballooning representation, and numerically verified by making use of the finite difference methods. Analytic expressions for the poloidal Reynolds stresses, defined on a rational surface, are given for both the weakly and the strongly up-down asymmetric ITG modes. It is shown that the poloidal stresses of both modes can be interpreted as a superposition of a monopole and a dipole structure. For comparison with the experiment, the stresses are calculated for L-mode discharge parameters on five machines. Analytic exp...