GEOMETRY OF SINGULAR STRUCTURES IN MAGNETOHYDRODYNAMIC FLOWS

The flattening of current sheets is investigated by means of numerical simulations of the ideal incompressible magnetohydrodynamic equations in two dimensions. The use of adaptive mesh refinement techniques all ows one to resolve the more and more singular structures and to follow the exponential growth of current density. The numerical results are in good agreement with a scaling ansatz proposed by Sulem et al, [J. P lasma Phys. 33, 191 (1985)]. The geometry of the current sheets is cha racterized by the alignment properties of the deformation matrices. (C ) 1998 American Institute of Physics. [S1070-664X(98)01707-8]