Figure 3
The collision rate R, in the transient phase. (a) The collision rate R, during the transient phase, between a reference particle with St = 0.05 and all the other particles. The curves correspond to times t = 0.5 τ η (pink diamonds, uppermost curve), t = τ η (blue circles) and t = 1.5 τ η (red squares). The almost linear line with black triangles correspond the steady state distribution R ∞ result. Inset: Pseudo color plot of the collision rate R during the transient phase; the color bar is normalised with the maximum in R ∞. This snapshot is taken at time of the order of τ η . (b) The collision rate R as a function of time τ (normalised by τ η ) for different-sized particles. We show representative plots for the case when St 1 = 0.96 and for (i) St 2 = 0.053 (pink circles), (ii) St 2 = 0.03 (blue diamonds), and (iii) St 2 = 0.005 (red squares). We observe a rapid decrease in the collision rate with time till it saturates to the asymptotic value R ∞ at large times.
