planes. Branching points are found on the central stagnation line at z ¼ Æ2:0 and
z ¼ Æ1:0. Branchings conserve the total index +1. The stagnation graph of Fig. 7.3
conveys complete information on the velocity field (7.60) in compact and economical form.
Fig. 7.3 Perspective view of
the stagnation graph of the
Gomes flow, Eq. (7.60), for
jzj\2:5. The central
stagnation line coincides with
the z axis. Green (red) lines
correspond to clockwise
(anticlockwise) vortices in
Figs. 7.1 and 7.2, saddle lines
are blue
Fig. 7.2 The Gomes flow, Eq. (7.60), on the z ¼ 0 plane. The color code is the same as in Fig. 7.1
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