Figure 2: Simulation at time t=0.2 using front tracking and dimensional splitting with grid refinement.

Discretization parameters from top to bottom:   Dx = Dy = (1/30, 1/60, 1/120).
Number of equally spaced time steps:   70, 140, and 280.
Local refinement by a factor two in each direction.
Fraction of refined blocks at final time:  54%, 35%, and 21%.