All integrable Hamiltonian systems are alike, while each nonintegrable one is nonintegrable in its own way
halting a rotating cylinder
A rotating cylinder in an infinite fluid generates a stable rotational flow, but if the cylinder is suddenly halted, then an unstable flow is induced. Paul Cardinaels has kindly provided the Gerris simulation data for such a flow illustrating the vortex generation and shedding.
vfplot -v -w8i -m5/5/-0.4 -s1e-4 -i300/5 \ -P0.1m -f100 -l0/1in --cache 256 \ --aspect 3.0 --glyph triangle \ -o vfplot.eps u.grd v.grd
Download the plot as pdf.