DOI: 10.1615/ICHMT.2009.TurbulHeatMassTransf
ISBN Print: 978-1-56700-262-1
ISSN: 2377-2816
Energy exchange in magnetohydrodynamic decaying isotropic turbulence
要約
We investigate decaying magnetohydrodynamic turbulence subject to (i) a uniform mean magnetic field and (ii) an initially random magnetic field. Specifically, we seek to examine the physical mechanisms driving kinetic-magnetic energy exchange. In the fluctuating magnetic field simulation case we observe increase in enstrophy (forward cascade rate) and a monotonic approach to equipartition between kinetic and magnetic energies. In the uniform magnetic field simulations it is seen that the turbulent energy which is initially exclusively in velocity field fluctuations is rapidly transferred to magnetic fluctuations in a fraction of eddy turn-over time. At later times, the two energies tend toward equipartition but the approach is non-monotonic. We also investigate Lorentz force behavior, enstrophy evolution and vorticity alignment with the strain-rate tensor.