Open AccessChaos in turbulence driven by the magnetorotational instability
Author(s) -
Winters Wayne F.,
Balbus Steven A.,
Hawley John F.
Publication year - 2003
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2003.06315.x
Subject(s) - physics , turbulence , magnetorotational instability , lyapunov exponent , chaotic , shearing (physics) , instability , formalism (music) , classical mechanics , mechanics , statistical physics , magnetohydrodynamics , nonlinear system , magnetic field , thermodynamics , art , musical , quantum mechanics , artificial intelligence , computer science , visual arts
Chaotic flow is studied in a series of numerical magnetohydrodynamical simulations that use the shearing box formalism. This mimics important features of local accretion disc dynamics. The magnetorotational instability gives rise to flow turbulence, and quantitative chaos parameters, such as the largest Lyapunov exponent, can be measured. Linear growth rates appear in these exponents even when the flow is fully turbulent. The extreme sensitivity to initial conditions associated with chaotic flows has practical implications, the most important of which is that hundreds of orbital times are needed to extract a meaningful average for the stress. If the evolution time in a disc is less than this, the classical α formalism will break down.