Magnitude of velocity divergence in simulations of the Kelvin–Helmholtz instability with the initial Mach number $\mathcal{M}$₀ = 10⁻² on a 512 × 256 grid. The results are shown at t = 0.8 $\mathcal{M}$₀⁻¹. Rows and columns show different reconstruction schemes and numerical flux functions, respectively. The small-scale structure produced by the LIN+VL, PPM84, and PPM08 schemes, which does not occur with the LIN, PAR, and PSH schemes, is caused by the use of limiters.