Astronomy and Astrophysics – Astronomy
Scientific paper
Dec 1998
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1998aas...193.7701c&link_type=abstract
American Astronomical Society, 193rd AAS Meeting, #77.01; Bulletin of the American Astronomical Society, Vol. 30, p.1370
Astronomy and Astrophysics
Astronomy
Scientific paper
In the frame of standard two-scale turbulence theory, we reconsider the dynamo coefficient alpha in incompressible isotropic helical MHD turbulence by taking the nonlinear effects of <{B}>, the large-scale magnetic field into account. Contrary to standard kinematic dynamo theory where alpha has only contribution from the kinetic helicity of turbulence velocity field, we find(Field, Blackman and Chou, 1998) that nonlinear dynamo alpha effect has contributions from current helicity of turbulen ce magnetic field, too. Our final result of alpha -effect is expressed in terms of statistical quantities that can be calculated from numerical simulations of the case <{B}>=0. We also show(Chou and Fish, 1998) that non-unit Prandtl number {Pr} =ν/λ, where nu and lambda are molecular viscosity and magnetic diffusivity, will affect the non-triviality of alpha . Our calculation shows that alpha remains finite in the limit of infinite magnetic Reynolds number, in support of Kraichnan(1979)'s analysis, but contrary to the simulation of Cattaneo and Hughes(1996).
Blackman Eric G.
Chou Hongsong
Field George B.
Fish Vincent
No associations
LandOfFree
A New Derivation of Nonlinear alpha -Effect in Dynamo Theory 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 A New Derivation of Nonlinear alpha -Effect in Dynamo Theory, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A New Derivation of Nonlinear alpha -Effect in Dynamo Theory will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-996582