2.6 Application of the Progressive Asymptotic Approach Procedure 35 (t = 0s) (t = 1 × 10 13 s) (t = 2 × 10 13 s) (t = 3 × 10 13 s) (t = 4 × 10 13 s) (t = 5 × 10 13 s) Fig. 2.17 Particle trajectories in the porous medium (Case 2)