Numerical Simulations of a Two Component Advective Flow for The Study of   the Spectral and Timing Properties of Black Holes
  Two component advective flows are the most physical accretion disks which arise from theoretical consideration. Since viscosity is the determining factor, we investigate the effects of viscous stresses on accretion flows around a nonrotating black hole. As a consequence of angular momentum transfer by viscosity in an accretion flow, the angular momentum distribution is modified. We include cooling effects and found that a Keplerian disk is produced on the equatorial plane and the flow above and below remains sub Keplerian. This gives a complete picture to date, of the formation of a Two component advective flow around a black hole. 
Kinsuk Giri and Sandip K. Chakrabarti
astro-ph.HE