HYDRODYNAMICAL CALCULATIONS TOWARDS STEADY-STATE STRUCTURES IN BOUNDARY-LAYERS IN ACCRETION DISKS .2. 2-D MODELS

The efficient hydrodynamical solver developed by Hujeirat & Rannacher (1994) is applied to search for steady state solution for the set of t ime-dependent Navier-Stokes equations describing a 2-D boundary layer around a non-magnetic white dwarf. We present the results of four mode l calculations carried out on the viscous time scale. The results indi cate: 1) the accreted matter loses most of its angular momentum via a shock in the boundary layer and forms a dense, quasi-spherical and pre ssure supported shell in some cases and belts in others, 2) the viscos ity in the disk is too large, modifying the viscosity prescription is necessary to prevent dissolution of the disk, 3) formation of circulat ions is observed in the shock-near regions whenever the angular veloci ty undergoes strong vertical variations near the equator or in the abs ence of cooling via thermal diffusion, 4) at least under optically thi ck conditions, the angular velocity and the temperature achieve a rela tively broad maxima in the equatorial region, and 5) to resolve the th ermal structure of BL-AD consistently, it is necessary to consider the vertical variation of angular velocity.