Radius r_sh of the shell as a function of time, calculations of the RING code, the evolution with the external gravitational potential: the radius in the plane (left panel) and the z-extent (right panel). Left panel: black colour corresponds to the basic model, blue colour to the model with 10x higher energy input and density, red colour to the model with 10x lower energy input and density. Different line types are dedicated for the average values r_ave (solid), the maximum r_max (dashed) and minimum r_min (dotted) values. Right panel: z-extent of the basic model in the homogeneous medium (black), the Gaussian distribution with a thickness 500 pc (blue) and Gaussian distribution with a thickness of 200 pc (red; models with 10x higher and lower energy input and density are added). In both panels the basic model from Fig. 9 is overlaid in green.