  A thickening at the outer edge of the accretion disk is usually invoked to
explain the dips in the light curves of cataclysmic variables with stationary
disks at phases ~0.7. The non-collisional interaction between the stream and
the disk in the stationary solution raises the question of why matter appears
at a considerable height above the accretion disk in such systems. Our
three-dimensional numerical modeling demonstrates that a thickening of the halo
above the disk can appear even in the absence of a direct collision between the
stream and the disk. In the gas-dynamical flow pattern described with the
"hot-line" model, a considerable fraction of the matter is accelerated in the
vertical direction during the flow's interaction with the circumdisk halo. The
vertical motion of the gas due to the presence of the z component of the
velocity leads to a gradual thickening of the circumdisk halo. The computations
reveal the strongest thickening of the halo above the outer edge of the disk at
phases ~0.7, in agreement with observations for stationary-disk cataclysmic
variables. This supports the hot-line model suggested earlier as a description
of the pattern of the matter flows in semi-detached binaries, and presents new
possibilities for interpreting the light curves of such systems.
