Coupling the two-fluid/Maxwell system to Magnetohydrodynamics/Ohm’s law

将二流体/麦克斯韦系统与磁流体动力学/欧姆定律耦合

• 批准号: 501208495
• 负责人: Professor Dr. Rainer Grauer
• 金额: --
• 依托单位: Institut für Theoretische Physik I: Plasma-, Laser- und Atomphysik
• 依托单位国家: 德国
• 项目类别: Research Units
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/501208495?language=en
• 关键词: Coupling; two; fluid; Maxwell; system

Astrophysical and space plasmas can be considered to be collisionless. The spatial and temporal scales occurring in such plasmas span more than 7 orders of magnitude from the finest kinetic to the global scales. Therefore, a multiscale/multiphysics modelling of plasmas is essential.In this project we consider the surface coupling of the two-fluid/Maxwell with the magneto-hydrodynamic (MHD) description. The transition from the two-fluid/maxwell to the MHD description contains several singular limits: i) the speed of light tends to infinity, ii) the ratio of Debye to system length vanishes and the electron mass is neglected. This leads to interesting questions when coupling MHD to the two-fluid/Maxwell system, such as: i) How can the information missing in the MHD be "reconstructed" to define consistent fluxes at the boundaries of the two descriptions? ii) How can a consistent energy density be formulated? iii) How can refinement criteria be defined to indicate when the MHD description is no longer appropriate? All these questions will be addressed in this project.This project is part of the DFG research unit "Structure-Preserving Numerical Methods for Bulk- and Interface-Coupling of Heterogeneous Models (SNuBIC)".

天体物理和空间等离子体可以被认为是无碰撞的。发生在这样的等离子体的空间和时间尺度跨越超过7个数量级，从最好的动力学全球尺度。因此，等离子体的多尺度/多物理模型是必不可少的。在本项目中，我们考虑了具有磁流体动力学（MHD）描述的双流体/麦克斯韦的表面耦合。从双流体/麦克斯韦到MHD描述的过渡包含几个奇异的极限：i）光速趋于无穷大，ii）德拜与系统长度之比为零，电子质量被忽略。这导致了有趣的问题时，耦合到两个流体/麦克斯韦系统的MHD，如：i）如何可以在MHD中丢失的信息被“重建”，以定义在两个描述的边界一致的通量？（二）如何制定一致的能量密度？iii）如何定义细化标准以指示MHD描述何时不再合适？所有这些问题都将在这个项目中得到解决。这个项目是DFG研究单元“非均匀模型体耦合和界面耦合的结构保持数值方法（SNUBIC）”的一部分。