Figure 2
From: Riemann solvers and Alfven waves in black hole magnetospheres

HLL Riemann solver vs. HLLI Riemann solver stationary Alfven discontinuity. Figure 2 shows two simulations of an isolated, stationary contact discontinuity. The density variable is shown. The result from the HLL Riemann solver is shown with crosses while the result from the HLLI Riemann solver is shown with dots.