Evolution of the pressure distribution in the shock reflection problem on a grid of 128 × 64 zones. From top to bottom a) after one time step, b) after four time steps, and c) after eight time steps with CFL ^{| u |  + c} ≈ 400. The full dual-time scheme (with ESDIRK23 temporal, and SLIP spatial discretization with minmod limiter) was used. For each state, 30 equidistantly spaced contours are shown between the pressure minimum and maximum.