An inverse coordinate multigrid method for free boundary magnetohydrostatics (Q5919263)

The equations of a two-dimensional magnetohydrostatic equilibrium with free pressure boundary conditions are expressed in inverse (flux) coordinates for both cartesian and axisymmetric geometries. The obtained quasi-linear elliptic system is solved using FAS full multigrid with line relaxation as the smoothing procedure. Convergence rates are generally very good with the exception of the expanding fluxtube model when they are slower but still acceptable.