Nonlinear Compressible Dynamos

Details Nonlinear Compressible Dynamos Nonlinear Compressible Dynamos

May 1999

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1999aas...194.5616d&link_type=abstract

American Astronomical Society, 194th AAS Meeting, #56.16; Bulletin of the American Astronomical Society, Vol. 31, p.914

Astronomy and Astrophysics

Astronomy

Scientific paper

The predictions of Mean Field Electrodynamics have been questioned because of the strong feedback of small scale magnetic structure on the velocity fields. In 2-D, this nonlinear feedback results in a lengthening of the turbulent decay time. In 3-D alpha-quenching is predicted. Previous studies assumed a homogeneous fluid. Here we present result of numerical solutions of fully compressible, nonlinear dynamos in two and three dimensions. In two dimensions, we consider an adiabatically stratified layer which experiences a constant shear. A mean-field alpha effect is introduced which is uniform over the layer. This system admits dynamo solutions of both the alpha -omega and alpha (2) varieties. This system also experiences a random thermal forcing which generates an additional turbulent diffusion. We seek to understand both the nonlinear actions of this system and the impact of the turbulent motions upon it. The magnetic flux in the convecting region above has a strong influence on the evolution of the dynamo. In three dimensions we model the generation of magnetic field in an adiabatic, stratified layer with random thermal forcing and an imposed velocity shear across the layer. Rather than introduce an artificial alpha effect, we seek a fully self consistent periodic dynamo. We therefore introduce a uniform rotation to the system which, in conjunction with the random forcing produces a mean helicity to the flows. We present the results of these calculations and their implications for the solar cycle. This work is supported by NASA grant: NAGW-5154

Affiliated with

Also associated with

No associations

Rating

Nonlinear Compressible Dynamos 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 Nonlinear Compressible Dynamos, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Nonlinear Compressible Dynamos will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1120853