论文标题
使用通量管代码$ \ texttt {stella} $的径向全局陀螺仪模拟的新颖方法
A novel approach to radially global gyrokinetic simulation using the flux-tube code $\texttt{stella}$
论文作者
论文摘要
在磁通管代码$ \ texttt {stella} $中实现了一种全局陀螺仪仿真的新方法。这是通过在湍流的垂直尺度长度中使用陀螺仪方程的辅助扩展来完成的，该湍流最初是由Parra和Barnes [Plasma Phys]得出的。受控的融合，$ \ textbf {57} $ 054003，2015]，它允许使用傅立叶基函数，同时启用径向配置文件变化的效果，以扰动方式包含。磁性几何形状的径向变化是通过利用通过泰勒膨胀获得的毕业生 - shafranov方程和米勒平衡方程的全局扩展。还开发了采用多个通量管模拟的径向边界条件，它是在全球模拟中使用的常规Dirichlet径向边界条件的更具身体动机的替代。结果表明，这些新的边界条件消除了使用光谱基础表达非周期函数时在径向边界附近产生的许多数值伪像。然后，我们使用许多标准测试用例线性和非线性基准进行新的方法。
A novel approach to global gyrokinetic simulation is implemented in the flux-tube code $\texttt{stella}$. This is done by using a subsidiary expansion of the gyrokinetic equation in the perpendicular scale length of the turbulence, originally derived by Parra and Barnes [Plasma Phys. Controlled Fusion, $\textbf{57}$ 054003, 2015], which allows the use of Fourier basis functions while enabling the effect of radial profile variation to be included in a perturbative way. Radial variation of the magnetic geometry is included by utilizing a global extension of the Grad-Shafranov equation and the Miller equilibrium equations which is obtained through Taylor expansion. Radial boundary conditions that employ multiple flux-tube simulations are also developed, serving as a more physically motivated replacement to the conventional Dirichlet radial boundary conditions that are used in global simulation. It is shown that these new boundary conditions eliminate much of the numerical artefacts generated near the radial boundary when expressing a non-periodic function using a spectral basis. We then benchmark the new approach both linearly and nonlinearly using a number of standard test cases.
