Plasma Heating by Volumetric Large-scale Flows

Abstract:

We solve an incompressible magnetohydrodynamo system.
We simulate a series of high-resolution numerical simulations and aim at clarifying the mechanisms that lead to heating of the solar corona. The model consists of an initially uniform magnetic field that is slowly deformed by a volumetric prescribed flow.
The response of the system is to re-adjust the magnetic configuration by a series of non-ideal events that lead to the heating of the plasma. Our simulations show that the system develops an MHD turbulent state. The heating is intermittent and independent of Lundquist number. The time averaged magnetic and kinetic energies also are independent of Lundquist number.
Thereafter, we propose a phenomenological model to explain our finding. Our model provides the scaling laws that fairly describe the heating rate, the time averaged magnetic energy, and the time averaged kinetic energy.