(a)
(b)
(c)
(d)
(e)
(f)
Figure 14: Velocity field on the , plane obtained at different depths; cross-section (a) shows the velocity field on the surface, cross-section (b) at 0.011 m, cross-section (c) at 0.023 m, cross-section (d) at 0.046 m, cross-section (e) at 0.58 cm, and (f) at the bottom.