Time evolution of the bow shock + cavity flow predicted by the analytic model for two choices of the wind velocity: v_w = 0 (leftframe) and v_w = 0.4v_j (right frame). The dark region is the empty part of the cavity (swept-up in the thin shell bow shock) and the brown region is the part of the cavity that has been refilled by the disk wind (this region being of course absent in the v_w = 0 model of the left frame). For both models, we show snapshots corresponding to t = 2L₀/V_j, 4L₀/V_j, and 8L₀/v_j), which result in positions z_j = 2L₀, 4L₀, and 8L₀ for the working surface (see the labels on the top left of each frame). Both models have v₀ = 0.2v_j