  This study utilizes computations based on soft-particle discrete element
method for investigating the scaling of velocity in a two-dimensional silo
draining under gravity. We focus on the region situated directly above and in
proximity to the outlet, referred to as the region of orifice influence (ROI).
The velocity at the exit scales with the outlet size, in agreement with
previous studies. The velocity in the ROI upstream of the outlet, however, does
not collapse to a single curve when scaled with the outlet size. We show that
the height of an $\textit{equi-inertial}$ curve, which is defined to be a curve
on which the inertial number is constant, can be employed for scaling the
velocity in the ROI. The velocity corresponding to an equi-inertial curve, when
measured relative to the outlet velocity, is considered for scaling. Results
show that the scaling holds very well for low inertial number corresponding to
the dense flow regime, whereas it breaks down for high inertial number region.
