Axi-symmetric young sun simulations, 2D, with A-MaZe (left panels, 256² mesh unless otherwise stated) and MUSIC (right panels, “Low 3” case in Pratt et al. 2016). Shown are the total kinetic energy in the domain, scaled to a full spherical layer (0 ≤ θ ≤ π, 0 ≤ φ ≤ 2π, 0.21 ≤ R ≤ 0.94), as function of time (different resolutions color coded for A-MaZe, shifted in time such as to ramp up simultaneously), as well as radial profiles of volume-weighted v_rms and its decomposition into radial and tangential component (middle and bottom panels, solid lines give time averages, dotted lines indicate the range) after convection has become quasi-stationary. The black long-dashed line (middle right panel) shows the convective velocity calculated within Mixing Length Theory formalism. We note that the y-axes in panels e and f are different.