2020 Volume 15 Pages 2401024
This study investigated the energy transfer of a fully developed freely decaying homogeneous isotropic turbulence of a Hall magnetohydrodynamic medium from the perspective of the interaction between the ion cyclotron (IC) and whistler (Wh) modes. The variables were decomposed using generalized Elsässer variables (Galtier, J. Plasma Phys. 72, 721 (2006)), which are given by a combination of velocity and magnetic fields. To analyze the energy transfer between these coupled variables, an analytical-mechanical approach was introduced that guaranteed both the Galilean covariance and the detailed energy balance for each decomposed mode. A remarkable asymmetry of the energy transfer between the IC and Wh modes was found. In the present study,almost one-sided energy transfers from the IC to the Wh modes were observed. In addition, a shell-to-shell transfer analysis revealed relatively weak inter-mode interactions with nonlocal features, while the intra-mode interactions were both intense and local.
