Hysteresis cycle in a turbulent, spherically bounded MHD dynamo model

Details Hysteresis cycle in a turbulent, spherically bounded MHD dynamo model Hysteresis cycle in a turbulent, spherically bounded MHD dynamo model

Jan 2009

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009njph...11a3027r&link_type=abstract

New Journal of Physics, Volume 11, Issue 1, pp. 013027 (2009).

Physics

4

Scientific paper

We report direct numerical magnetohydrodynamic simulations at low magnetic Prandtl numbers of a turbulent two-cell flow in a bounded, spherical geometry, driven by a constant body force. The flow amplifies infinitesimal magnetic perturbations if the magnetic Reynolds number Rm is larger than a threshold Rmc, resulting in a self-excited equatorial magnetic dipole. However, finite amplitude perturbations to the magnetic field can trigger dynamo action below Rmc: a hysteresis cycle has been found that can sustain dynamo action in an interval Rm0 < Rm < Rmc. The instability is therefore governed by a subcritical bifurcation. This hysteretic behaviour is associated with changes in the turbulent velocity field caused by the finite amplitude magnetic field. It is then shown that the dynamo state can be accessed by transiently applying a magnetic field from an external source. Finally, a dynamo state with characteristics different from the self-excited case is found in the vicinity of Rm0.

Affiliated with

Also associated with

No associations

Rating

Hysteresis cycle in a turbulent, spherically bounded MHD dynamo model 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 Hysteresis cycle in a turbulent, spherically bounded MHD dynamo model, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hysteresis cycle in a turbulent, spherically bounded MHD dynamo model will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1151564