Magnetic dynamo action in two-dimensional turbulent magneto-hydrodynamics

Technical Report · Tue Jun 01 00:00:00 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: Univ. of Iowa, Iowa City (United States). Dept. of Physics and Astronomy; National Center for Atmospheric Research, Boulder, CO (USA)
• Sponsoring Organization: US Energy Research and Development Administration (ERDA)
• DOE Contract Number: E(11-1)-2059
• OSTI ID: 7130490
• Report Number(s): COO-2059-54
• Country of Publication: United States
• Language: English

Related Subjects

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