Astronomy and Astrophysics – Astrophysics
Scientific paper
2001-06-29
Astronomy and Astrophysics 380, p.359-372 (2001)
Astronomy and Astrophysics
Astrophysics
14 pages, 17 figures, 5 tables, submitted to Astron. & Astrophys
Scientific paper
10.1051/0004-6361:20011388
The possibility of non-helical large scale dynamo action is investigated using three-dimensional simulations of global accretion discs as well as idealized local simulations without rotation and only shear. Particular emphasis is placed on a certain correlation between vorticity and azimuthal velocity gradient which has been predicted to drive large scale dynamo action, independent of the presence or absence of kinetic helicity. In the global disc simulations two types of behaviours are found: those which do show this type of velocity correlation and those which do not. The former ones are typically also the cases where the resistivity is larger. The latter ones show signs typical of dynamo action based on the usual helicity effect. In the idealized simulations without rotation and just shear the above correlation is found to be particularly strong. In both cases there is, as expected, a systematic flux of magnetic helicity through the midplane. However, very little helicity flux leaves the domain through the top and bottom boundaries. The idealized simulations reveal that much of this systematic flux comes from the rotational component of the helicity flux and does not contribute to its divergence.
Arlt Rainer
Brandenburg Axel
No associations
LandOfFree
Search for non-helical disc dynamos in simulations does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Search for non-helical disc dynamos in simulations, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Search for non-helical disc dynamos in simulations will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-330946