Density, velocity and temperature profiles of models from the α = 3 sequences, selected after  ≃3500 years of post-AGB evolution, and for the metallicities indicated above each panel. The central star is at the origin, and its parameters are T_eff ≃ 41000 K and L = 5534 L_⊙. The velocity oscillations seen in some early models are due to a temporary numerical instability in the hot bubble caused by our heat conduction routine, but have no impact on the model dynamics. Upper row: the radial profiles of heavy particle densities (thick solid), electron densities (dotted), and gas velocities (thin solid). The particle densities are normalised and must be multiplied by the factors given in the individual panels to get the true densities. Lower row: the radial run of the electron temperatures, where the dotted lines represent the equilibrium temperatures (see text for the details, and also Sects. 3.1.2 and 3.1.3).