Taylor Vortex Flow
Onset
Measurements of Torque G:

(Donnelly
and Simon, J. Fluid Mech. 7 (1960) 401)
Non-smooth behavior at the transition point to Taylor vortices.
More complicated flows for co-rotating cylinders:
Twisted Taylor vortices

Wavy inflow boundaries

Wavelets

(Andereck,
Liu and Swinney, J. Fluid Mech. 164 (1986) 155)
Map of flow regimes for independently rotating cylinders:

(Andereck,
Liu and Swinney, J. Fluid Mech. 164 (1986) 155)