2.5维自适应磁场重联MHD模式

磁雷诺数(R_m)是影响磁场重联的重要因素. 真实的物理环境中R_m往往很高, 例如, 在行星际空间和太阳日冕中R_m通常大于104量级. 高R_m条件下的磁重联表现出很多异常特性, 然而高R_m条件下的磁场重联数值模拟需要很高的时空分辨率, 否则很难分辨出重联过程中形成的薄电流片. 本文基于自适应软件包PARAMESH将并行自适应网格技术引入磁场重联数值模拟, 建立了一个2.5维自适应磁场重联MHD模式, 研究高磁雷诺数条件下重联的动态演化过程, 进而将不同磁雷诺数的参数进行对比研究. 结果表明, 该模式可以自动捕捉到磁场重联产生的奇性电流片, 高磁雷诺数条件下产生的慢激波结构可提供一种快速磁能释放机制. 

2.5D AMR MHD Magnetic Reconnection Model

Magnetic reconnection is one of the hot topics in space physics. The magnetic Lundquist number can influence the magnetic reconnection process drastically. Magnetic Lundquist number is always very large in many real physical environments, for example, higher than 104 in interplanetary space and solar corona. Magnetic reconnection with enormously large Lundquist number behaves many new characteristics, while magnetic reconnection simulation needs very high grid resolution, or it can't resolve the thin current sheets formed in the magnetic reconnection. With the help of the Adaptive Mesh Refinement (AMR) package named PARAMESH, AMR technique was introduced into magnetic reconnection simulations and a two and half dimensional (2.5D) AMR magnetic reconnection model was developed. The dynamic reconnection process with different magnetic Lundquist numbers was studied. The results showed that this model can automatically capture the near-singular current sheets with the development of the magnetic reconnection and the slow-mode shock structures formed in the magnetic reconnection process with high magnetic Lundquist number provide a possible way for fast magnetic energy conversion.