FIG. 4.
The trajectories X(t) in the xy-plane with a background source–sink pair with strength ratio γ = 5 and for various Stokes numbers St: (a) St = 10−8, (b) St = 10−6, (c) St = 10−4, and (d) St = 10−2. In these plots, R = 0.001, Λ = 0.0001, and |g| = 1. The trajectories will be different for different choices of R. The dashed circle indicates the predicted maximal distance that a fluid parcel can travel when ejected from the source. The source is indicated by a green filled circle, and the sink is indicated by a red filled circle.