Magnetic field amplification and saturation in two-dimensional magnetohydrodynamic turbulence
Two-dimensional magnetohydrodynamic turbulence is investigated for weak initial magnetic fields using numerical simulation. It is found that the magnetic field is amplified owing to the formation of flux sheets with saturation due either to resistive diffusion (kinematic regime) or to nonlinear effects (dynamic regime). Due to the strongly disparate kinetic and magnetic energy spectra in the kinematic regime, dynamic interaction on a small scale already occurs at very small global energy ratios (E(M)/E(V), giving rise to strongly enhanced kinetic energy dissipation. In the fully dynamic regime global magnetic and kinetic energies become tightly coupled, with E(M)/E(V) being approximately constant in time and the energy dissipation rates being independent of the collisional diffusion coefficients. Finally, the effect of the magnetic Prandtl number is discussed.
Bibliographic Reference: Article: The Physics of Fluids B, Vol. 2 (1990) No. 8, pp. 1787-1793
Record Number: 199110058 / Last updated on: 1994-12-02
Original language: en
Available languages: en