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tokens: et al. ( 1996 ) and Giri Chakrabarti ( 2013 ): the cooling rate is ∝ρ 2 T β , where β > 0 is the cooling index. For β = 0.5, the process is bremsstrahlung. In order to ensure the formation of a cold Keplerian disc, we must use higher β in order for the cooling time-scale to be reduced compared with the infall time-scale. Thus we increase cooling gradually inside the would-be Keplerian component. When the region with Keplerian distribution becomes optically thick, the index is raised to 0.6 as used in earlier simulations. This saves the prohibitive time required for Monte Carlo simulations, in order that normal bremsstrahlung radiation may be emitted as blackbody radiation in the optically thick region. Giri et al. ( 2015 ) found that the result is insensitive to the exact cooling process, since blackbody cooling also produced the expected standard disc in the equatorial plane in their simulation. In Fig. 2 (a) and (b), we show the density, velocity and specific angular momentum distribution at t = 19.8 s just before viscosity is turned on. As can be seen clearly, a standing shock at a distance of about 40 r g is formed, with a sudden rise of density and pressure. The colour (online) scale is on the right. The outflow starts in the region between the centrifugal barrier and the funnel wall (Molteni et al. 1996 ). Specific angular momentum remains at its initial value of 1.7. Figure 2. (a) Density, velocity and (b) specific angular momentum distribution at t = 19.8 s just before viscosity is turned on ( t 0 in Fig. 1 a). Here, a standing shock has formed at a distance of about 40 r g , with a sudden rise of density and pressure, and outflow has started between the centrifugal barrier and funnel wall region. Density ρ is chosen to be unity in dimensionless units at the injection radius. In (b), the specific angular momentum distribution is represented by the solid curve for comparison with the Keplerian distribution (dot–dashed curve). At t 0 , the specific angular momentum remains at its initial injected value of 1.7. After viscosity is turned on, as matter accretes, initially the viscous stress near the inner edge remains close to zero. As α increases with time, −α P becomes significant close to the inner edge, due to high pressure, and angular momentum transport starts efficiently. On the equatorial plane, this result is similar to what was seen in Chakrabarti Molteni ( 1995 ). However, at the outer edge, though α itself is high, pressure being very low, the stress is not high enough and thus angular momentum transport remains slower. 4.1 Results using viscosity description of Case I In this case, we use . We chose α 0 = 0.12, which is above the critical value of 0.074 required for a Keplerian disc to form with the used injected parameters. In Fig. 3 (a)–(b), we show the distributions at t = 41.58 s of (a) the density and velocity vector and (b) the angular momentum distribution (solid). To compare, we also plot the Keplerian distribution