can cause numerical artefacts.

Following @artymowicz96, we calculate the time scale on which the disc undergoes significant viscous evolution, $\tau_{\nu}=Re\,\Omega^{-1}$, assuming the Reynolds number, $Re$, and angular frequency, $\Omega$, are given by: $$\label{eq:reynolds_eda1}
Re = \frac{(r/\langle h \rangle)^2}{\alpha_{\nu}}\\
\Omega = \sqrt{\frac{GM_{*}}{r^3}}\\$$ with $r$ the radial distance to the star and $\langle h \rangle$ the (resolution-dependent) average smoothing length in the disc at that radius. For a simulation of 16.000 disc particles, and assuming the corresponding $\alpha_{\nu}$, this gives us a viscous time scale, $\tau_{\nu}$, of roughly 10.000 years at 10 AU. We can also calculate the physical viscous time scale at 10 AU by replacing $\langle h \rangle$ with the scale height of the disc, $H=\frac{c_s}{\Omega}$, at that radius. This leads to a time scale of $3\times10^5$ years. In order to remain safely in the regime where the simulation is not dominated by viscous evolution of the disc, we evolve the whole set-up for 2500 years and start the inflow at $t=0$. The numerical viscosity in the disc changes during the simulations with Gadget2 and we will discuss the numerical effects in Sec. \[sec:convergence\_eda1\] and \[sec:consistency\_eda1\].

Distinguishing the disc from the ISM {#sec:disc_recognition_eda1}
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To determine how much 