Blob velocity as a function of time for three setups with T₀ = 2 × 10⁶ K, Δ = 0.5 Mm, and (a) ρ_b0 = 10⁻¹⁰ kg m⁻³, (b) ρ_b0 = 5 × 10⁻¹⁰ kg m⁻³, and (c) ρ_b0 = 10 × 10⁻¹⁰ kg m⁻³. The green curve comes from the numerical solution of Equations (1)–(3), whereas the analytical approximation of Equation (18) is given by the blue and orange curves for the best fit of D and for D = 0.6, respectively. The variables τ and V_b are the dimensionless time and blob speed (see Section 3.2). (d) (Unsigned) maximum blob velocity, v_b, max, vs. Δ dr (the meaning of the different symbols is given in the figure legend).