Three-dimensional Modeling of the Matter Flow Structure in Semidetached   Binary Systems
  Results of numerical simulations of matter flows in a semidetached binary system similar to the low-mass X-ray binary X1822--371 are presented. Three-dimensional modeling of the mass transfer gas dynamics makes it possible to investigate gas streams in the system and to study the influence of a common envelope. The presence of the common envelope leads to the absence of shock interaction between the stream of matter flowing from the inner Lagrange point and the gas in the accretion disk. The stream is deflected by the gas in the common envelope and approaches the disk tangentially, so that it does not cause any shock perturbation ("hot spot") on the disk. At the same time, the interaction of the stream with the common envelope leads to the formation of an extended shock wave along the edge of the stream. The observational manifestation of this shock is estimated to be equivalent to that of a hot spot in the disk. The calculated accretion disk parameters are presented. 
D.V.Bisikalo(1), A.A.Boyarchuk(1), O.A.Kuznetsov(2), V.M.Chechetkin(2)   ((1) Inst. of Astronomy of Russian Acad. Sci., Mosc...