Orthonormal Divergence-free Wavelet Analysis of Energy Transfer in Magnetohydrodynamic Turbulence

For the purpose of clarifying mechanism of local structure formations in magnetohydrodynamic (MHD) turbulence, energy transfers among various scales and positions of magnetic/kinetic energies in the course of roll-up processes of vortices are studied by direct numerical simulations (DNS) and orthonormalwavelet analysis. Initial shear layers are perturbed by three-dimensional random perturbations, and roll up to form tubular vortices which are connected to each other by blade structures. The energy transfers in this process is considered to be modified from that in the neutral fluid turbulence in the presence of large-scale magnetic fields. Information on scales provided by the wavelet analysis are used to study scale-to-scale energy transfers in the roll-up processes. The scale-to-scale analysis suggests that large scale flow structures directly excite magnetic fields with various scales. Energy exchange between the kinetic and magnetic field energies will also be examined from the points of views of local analysis of scale-to-scale energy transfers.