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Compressible MHD in Spherical Geometry

Published online by Cambridge University Press:  12 April 2016

Lorenzo Valdettaro  and
Maurice Meneguzzi
Lorenzo Valdettaro
Affiliation:
CERFACS, 42 Av. G. Coriolis, 31057 Toulouse CEDEX, France
Maurice Meneguzzi
Affiliation:
CERFACS, 42 Av. G. Coriolis, 31057 Toulouse CEDEX, France

Abstract

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The generation of magnetic field by a conducting, compressible fluid inside a spherical shell is studied by direct numerical simulations. A pseudo-spectral method is used in order to resolve accurately all the scales present in the problem. The range of parameters considered is the following: a unit Prandtl number, Rayleigh numbers up to 100 times critical, Taylor number 625, an aspect ratio of 2, a Mach number slightly less than 1, and pressure and temperature scale heights of the order of the thickness of the shell. A dynamo effect is observed for magnetic Prandtl numbers larger than 1. We present the properties of the turbulent flow, the role of the helicity and of the differential rotation in the enhancement of the magnetic field, and the spectral properties of the flow fields.

Type
Part I Convection and turbulence as the basis of magnetic activity
Information
International Astronomical Union Colloquium , Volume 130: The Sun and Cool Stars: activity, magnetism, dynamos , 1991 , pp. 80 - 85
Copyright
Copyright © Springer-Verlag 1991

References

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