DYNAMOS IN ACCRETION DISKS WITH BOUNDARY-LAYERS

We consider the classic MHD turbulent dynamo operating in a thin, Kepl erian accretion disk powered by turbulent viscous stress. The characte r of the turbulence is encapsulated into two constant parameters: the Shakura-Sunyaev dimensionless viscosity, alpha(SS), and the Coriolis n umber, Omega = 2 tau(corr)Omega. The dependence of the total electrom otive force on alpha(SS) and Omega is derived, The nonlinear models a re calculated without taking into account the back-reaction of magneti c field on the structure of the disk. Such an approach is consistent p roviding that the magnetic Mach number, M(mag), is smaller than unity. The physical quantities within the boundary layer - the radial zone b etween the disk and the star where the rotational velocity of the accr eting material slows from nearly Keplerian to the stellar rotation rat e - are calculated due to the approach of Lioure and Le Contel (1993). As well it's possible to change the boundary conditions at the inner edge of the disk as done by Popham et al. (1993). The generated magnet ic field has a quadrupolar symmetry with respect to the equator, is mo stly confined within the disk's density scale-height and is concentrat ed in the radially inner part. of the disk. The magnetic field normali zed to the equipartition value has its maximum in the boundary layer.