Variational Integration for Ideal MHD with Built-in Advection Equations

[摘要] Newcomb's Lagrangian for ideal MHD in Lagrangian labeling is discretized using discrete exterior calculus. Variational integrators for ideal MHD are derived thereafter. Besides being symplectic and momentum preserving, the schemes inherit built-in advection equations from Newcomb's formulation, and therefore avoid solving them and the accompanying error and dissipation. We implement the method in 2D and show that numerical reconnection does not take place when singular current sheets are present. We then apply it to studying the dynamics of the ideal coalescence instability with multiple islands. The relaxed equilibrium state with embedded current sheets is obtained numerically.

[发布日期] 2014-08-05

[学科分类] 原子、分子光学和等离子物理

[关键词] Computational Physics;Computer Simulation;Magnetohydrodynamics (MHD)