Resistive magnetohydrodynamic studies of tearing mode instability with equilibrium shear flow and magnetic reconnection

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1992

OSTI ID:6820628

Ofman, L

Magnetic reconnection and tearing can play an important role in fusion experiments and in space plasmas. The magnetohydrodynamic (MHD) study of the linear and nonlinear evolution of the resistive tearing mode instability in the presence of equilibrium shear flow, and the reconnection of an x-point magnetic field configuration are discussed. Numerical solutions of the linearized time-dependent MHD equations and growth rate scaling are obtained. The results of the computations are compared to previous work, and the computed growth rate scalings agree with analytical predictions. The introduction of viscosity and small equilibrium shear flow alters the growth rate scaling considerably. When the shear flow is large, the growth rate behaves in a more complex way, and Kelvin-Helmholtz instability effects are present. The linear evolution of the double tearing mode with equilibrium shear flow and viscosity is investigated numerically. The dispersion relation for the growth rate of the double tearing instability is generalized to include flow. Relatively small shear flow at the resonant surfaces has a stabilizing effect on the double tearing mode. For Reynolds number comparable or larger than the magnetic Reynolds number a stabilizing effect is found. The nonlinear evolution of the tearing mode instability with equilibrium shear flow is investigated via numerical solutions of the resistive incompressible two dimensional MHD equations. The simulations are initiated with solutions of the linearized MHD equations. Magnetic energy release decreases, and the saturation time increases with shear flow. The validity of the numerical solutions is tested by verifying that the total energy and helicity are conserved. The reconnection of two-dimensional stressed x-type neutral point magnetic fields is studied via solution of the nonlinear incompressible and compressible resistive MHD equations. Solutions of the linear eigenvalue problem are obtained and compared to the MHD simulations.

• Research Organization: Texas Univ., Austin, TX (United States)
• OSTI ID: 6820628
• Country of Publication: United States
• Language: English

Related Subjects

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Ionospheric
& Magnetospheric Phenomena-- (1992-)
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700340 -- Plasma Waves
Oscillations
& Instabilities-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
DISPERSIONS
EQUILIBRIUM
FLUID MECHANICS
GROWTH
HELICITY
HELMHOLTZ INSTABILITY
HYDRODYNAMICS
INSTABILITY
INSTABILITY GROWTH RATES
MAGNETIC FIELDS
MAGNETIC RECONNECTION
MAGNETIC REYNOLDS NUMBER
MAGNETOHYDRODYNAMICS
MECHANICS
MIXTURES
NUMERICAL SOLUTION
PARTICLE PROPERTIES
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
REYNOLDS NUMBER
SATURATION
SHEAR
SOLUTIONS
SURFACES
TEARING INSTABILITY
VISCOSITY