The following vortex sheet computations were motivated
by the soap-film experiments of
A body moving in fluid at uniform speed
creates a free sinusoidal wake
which can be modeled by a suitably perturbed vortex sheet.
In this case,
the wake is symmetric about the horizontal centerline.
The final state resembles a classical Karman vortex street.
If the body oscillates in the
the vortices form an array of dipoles which propagate
on one side of the centerline.
With a different streamwise oscillation,
dipoles form and propagate on both sides of the centerline.
Y. Couder and C. Basdevant
Experimental and numerical study of vortex couples in
J. Fluid Mech. 173, 225-251
Vortex sheet computations: roll-up, wakes, separation,
Proc. AMS-SIAM Sem. on ``Vortex Dynamics and
Vortex Methods", C. Anderson & C. Greengard (eds.),
Lects. Appl. Math. 28, 385-402, AMS