Influence of equilibrium shear flow on peeling-ballooning instability and edge localized mode crash
Influence of equilibrium shear flow on peeling-ballooning instability and edge localized mode crash
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DOI：
10.1063/1.4751256
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发表时间：
2012-09
影响因子：
2.2
通讯作者：
P. Xi;X. Xu;Xiaogang Wang;T. Xia
中科院分区：
文献类型：
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作者：
P. Xi;X. Xu;Xiaogang Wang;T. Xia
E×B剪切流对剥离-气球模式及其随后触发的边缘局部化模式(ELM)崩溃具有双重作用。一方面，流动剪切可以稳定高n阶模式，并使模式沿极向扭曲，限制模式的径向范围，减小相应的ELM尺寸。另一方面，剪切流还引入了开尔文-亥姆霍兹驱动，它可以破坏剥离-气球模式的稳定性。平衡剪切流对剥离-气球模式和榆树破碎的总体影响取决于这两种影响之间的竞争。当流动剪切值很小时或很大时，可以减小榆树的尺寸。然而，对于中等的流动剪切值，开尔文-亥姆霍兹项的失稳效应占主导地位，导致更大的ELM崩溃。
The E × B shear flow plays a dual role on peeling-ballooning modes and their subsequently triggered edge localized mode (ELM) crashes. On one hand, the flow shear can stabilize high-n modes and twist the mode in the poloidal direction, constraining the mode's radial extent and reducing the size of the corresponding ELM. On the other hand, the shear flow also introduces the Kelvin-Helmholtz drive, which can destabilize peeling-ballooning modes. The overall effect of equilibrium shear flow on peeling-ballooning modes and ELM crashes depends on the competition between these two effects. When the flow shear is either small or very large, it can reduce ELM size. However, for moderate values of flow shear, the destabilizing effect from the Kelvin-Helmholtz term is dominant and leads to larger ELM crashes.