5% - eTheses Repository - University of Birmingham

Chapter 5
ft)
J k I
Figure 4. Varying the particle fall speed for a Rankine core of radius
0.006m and angular speed lOOrad/s. The particle quiescent fall speed
(m/s) is a) 1 b) 0.6 c) 0.5 d) 0.4 e) 0.35 f) 0.3 g) 0.25 h) 0.2 i) 0.1 j) 0.09
k) 0.07 1) 0.05. The core rotates anticlockwise and the bent
trajectories in b and c are due to the local pressure gradient acting
towards the centre of the core. The pressure gradient and fluid drag
are responsible for transporting the particle around the vortex in k
and 1.