Magnetic dynamo action in two-dimensional turbulent magneto-hydrodynamics

Technical Report · Tue Jun 01 04:00:00 EDT 1976

DOI:https://doi.org/10.2172/7130490· OSTI ID:7130490

Fyfe, D.; Joyce, G.; Montgomery, D.

Two-dimensional magnetohydrodynamic turbulence is explored by means of numerical simulation. Previous analytical theory, based on non-dissipative constants of the motion in a truncated Fourier representation, is verified by following the evolution of highly non-equilibrium initial conditions numerically. Dynamo action (conversion of a significant fraction of turbulent kinetic energy into long-wavelength magnetic field energy) is observed. It is conjectured that in the presence of dissipation and external forcing, a dual cascade will be observed for zero-helicity situations. Energy will cascade to higher wave numbers simultaneously with a cascade of mean square vector potential to lower wave numbers, leading to an omni-directional magnetic energy spectrum which varies as k/sup -1/3/ at lower wave numbers, simultaneously with a buildup of magnetic excitation at the lowest wave number of the system. Equipartition of kinetic and magnetic energies is expected at the highest wave numbers in the system.

• Research Organization: Iowa Univ., Iowa City (USA). Dept. of Physics and Astronomy; National Center for Atmospheric Research, Boulder, CO (USA)
• Sponsoring Organization: US Energy Research and Development Administration (ERDA)
• OSTI ID: 7130490
• Report Number(s): COO-2059-54
• Country of Publication: United States
• Language: English

Related Subjects

640430* -- Fluid Physics-- Magnetohydrodynamics
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
DIFFERENTIAL EQUATIONS
DIRECT ENERGY CONVERTERS
ENERGY
EQUATIONS
EQUATIONS OF MOTION
FLUID FLOW
FLUID MECHANICS
FOURIER ANALYSIS
HYDRODYNAMICS
KINETIC ENERGY
MAGNETOHYDRODYNAMICS
MATHEMATICAL MODELS
MECHANICS
MHD GENERATORS
TURBULENT FLOW
TWO-DIMENSIONAL CALCULATIONS