论文标题
在各种碰撞状态下，在1D有限的低温等离子体的模拟中遇到的数值挑战
Numerical challenges in the simulation of 1D bounded low-temperature plasmas with charge separation in various collisional regimes
论文作者
论文摘要
我们研究了在两个导电壁之间限制在实验室等离子体中的等离子体的1D几何形状。这些等离子体的特征是准中性散装，它通过称为鞘的薄边界层连接到墙壁，该鞘呈阳性带电。尽管分析解决方案在护套和鞘中可用，但通过一个分析溶液连接两个区域仍然是一个开放的问题，它需要与泊松方程耦合的流体方程的数值分辨率。当前的数值方案使用高阶离散化来正确捕获护套中的电子电流，从而在边界层中呈现不令人满意的结果，并且不适合所有可能的碰撞状态。在这项工作中，我们确定了尝试使用这种配置的模拟时出现的主要数值挑战，并通过数值分析提出了对观察到现象的解释。我们提出了一个具有控制扩散以及解决已确定问题的新离散边界条件的数值方案。
We study a 1D geometry of a plasma confined between two conducting floating walls with applications to laboratory plasmas. These plasmas are characterized by a quasi-neutral bulk that is joined to the wall by a thin boundary layer called sheath that is positively charged. Although analytical solutions are available in the sheath and the pre-sheath, joining the two areas by one analytical solution is still an open problem which requires the numerical resolution of the fluid equations coupled to Poisson equation. Current numerical schemes use high-order discretizations to correctly capture the electron current in the sheath, presenting unsatisfactory results in the boundary layer and they are not adapted to all the possible collisional regimes. In this work, we identify the main numerical challenges that arise when attempting the simulations of such configuration and we propose explanations for the observed phenomena via numerical analysis. We propose a numerical scheme with controlled diffusion as well as new discrete boundary conditions that address the identified issues.
