This work was completed by D.N. Beal, F. S. Hover, M.S. Triantafyllou, J.C. Liao, and G.V. Lauder, in a collaborative project between MIT and Harvard. Details can be found in the paper:
Beal, D. N., et al. "Passive propulsion in vortex wakes." Journal of Fluid Mechanics 549 (2006): 385-402.
(uploaded for the MIT towtank website)