Radial transport in a VELA disk. For the simulated galaxy VELA 7 at a redshift of z = 1.5, the top-left and -right panels show face-on maps of the cold gas surface density (Σ) and the two-dimensional radial velocity (v_r,2D), respectively, within a region spanning 3 R_d × 3 R_d, centered on the galactic center. The disk is large (R_d = 18.43 kpc) and thin (R_d/H_d ∼ 9). It is mainly supported by rotation, with ⟨V_rot⟩/⟨σ_r⟩∼3 and has a cold gas fraction of f = 0.18. Regions with no cold gas are shown as white in the surface density map and black in the radial velocity map. Dashed red circles mark the radial extent of the disk. Both maps exhibit strong non-axisymmetry, largely due to incoming cold gas streams. The middle left and right panels display the average radial velocity (V_r, in units of V_rot) and the radial mass flux (F_r, in units of ℳ/t_dyn), respectively, as functions of r, normalized by R_d, out to the disk radius. Here, V_rot and ℳ are the average rotational velocity and mass of all cold gas at r, and t_dyn = r/V_rot is the local dynamical time. The non-normalized V_r and F_r are shown in the bottom left and right panels, respectively. Beyond roughly 0.2 R_d, both V_r and V_rot are negative and tend to grow in magnitude with increasing r, albeit with some fluctuations, indicating a predominantly inflow-driven cold gas radial transport within the disk. The disk-averaged radial velocity is also negative and has a magnitude about 8% of the disk-averaged rotational velocity.