论文标题
草榆树的特征及其对分流热通量宽度的影响
Characteristics of grassy ELMs and its impact on the divertor heat flux width
论文作者
论文摘要
对60年代的稳态长脉冲高\ {beta} p东草榆木排放进行回合++湍流模拟。回合++线性模拟表明，不稳定模式频谱涵盖了从低N（n = 10〜15）剥离球模式（P-B）到高N（n = 40〜80）漂移-Alfvén的不稳定性的一系列环形模式数字。非线性模拟表明，低N剥离模式会触发ELM崩溃，并且在峰值压力梯度位置上产生了波动，即使漂移 - alfvén的不稳定占据了线性生长阶段，也会在尖峰梯度位置并径向向外散布。然而，漂移 - 阿尔夫温的湍流延迟了草榆木的发作，并随着波动延伸到基座顶部区域，增强了能量损失。仿真进一步表明，如果去除剥离驱动器，则波动振幅下降了一个数量级，而榆树崩溃消失了。由于强大的径向湍流传输，基于HD模型和ITPA多TOKAMAK缩放（或经验EICH缩放）的估计值大约大约2倍。
BOUT++ turbulence simulations are conducted for a 60s steady-state long pulse high \{beta}p EAST grassy ELM discharge. BOUT++ linear simulations show that the unstable mode spectrum covers a range of toroidal mode numbers from low-n (n=10~15) peeling-ballooning modes (P-B) to high-n (n=40~80) drift-Alfvén instabilities. Nonlinear simulations show that the ELM crash is trigged by low-n peeling modes and fluctuation is generated at the peak pressure gradient position and radially spread outward into the Scrape-Off-Layer (SOL), even though the drift-Alfvén instabilities dominate the linear growth phase. However, drift-Alfvén turbulence delays the onset of the grassy ELM and enhances the energy loss with the fluctuation extending to pedestal top region. Simulations further show that if the peeling drive is removed, the fluctuation amplitude drops by an order of magnitude and the ELM crashes disappear. The divertor heat flux width is ~2 times larger than the estimates based on the HD model and the ITPA multi-tokamak scaling (or empirical Eich scaling) due to the strong radial turbulence transport.
