Geometry of the jet as used in the simulation: the jet enters the domain at z₀ = 0.5 pc from the source with a width setting r_b as calculated assuming a first angle of 5°. A flaring-like case assumes a fixed angle θ, which is added to a reference cylindrical jet, thereby introducing a “virtual source location”. The actual domain of the simulation is comprised between z₀ and z_out for the axial direction and r = 0 and r_out for the radial direction. The velocity field is initiated in a finite region up to z₁, according to the formulae given in the text.