Mean-field view on rotating magnetoconvection and a geodynamo model

摘要: A comparison is made between direct numerical simulations of magnetohydrodynamic processes in a rotating spherical shell and their mean–field description. The mean fields are defined by azimuthal averaging. coefficients that occur the traditional representation electromotive force considering derivatives magnetic field up to first order calculated with fluid velocity taken from two different methods. While one does not use specific approximations, second based on first–order smoothing approximation. There satisfying agreement results both methods for sufficiently slow motions. For investigated example magnetoconvection derived simulation well reproduced level. simple geodynamo model discrepancy occurs, which probably consequence neglect higher–order force. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)