Conservation of Magnetic Helicity and Its Constraint on α-Effect of Dynamo Theory

Abstract

We show, with direct numerical simulation of three-dimensional magnetohydrodynamic turbulence with a mean magnetic field, B, that the time behavior of the dynamo α-effect is constrained by the dynamics of magnetic helicity. A time-scale tc is introduced such that for t < tc, the α-coefficient calculated from the simulation is close to the result given by Field et al (1999), αFBC ∼ − τc 3 (〈v · ∇ × v〉 − 〈b · ∇ × b〉); for t > tc, the α-coefficient can be approximated by αFBC/ (

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Cite this paper

@inproceedings{Chou2000ConservationOM, title={Conservation of Magnetic Helicity and Its Constraint on α-Effect of Dynamo Theory}, author={Hongsong Chou}, year={2000} }