Hysteresis has been observed in a study of the transition between laminar flow and vortex shedding in a quasi-two dimensional system. The system is a vertical, rapidly flowing soap film which is penetrated by a rod oriented perpendicular to the film plane. Our experiments show that the transition from laminar flow to a periodic Kármán vortex street can be hysteretic, i.e. vortices can survive a...

The sea surface imprints of Atmospheric Vortex Street (AVS) off Aleutian Volcanic Islands, Alaska were observed in two RADARSAT-1 Synthetic Aperture Radar (SAR) images separated by about 11 hours. In both images, three pairs of distinctive vortices shedding in the lee side of two volcanic mountains can be clearly seen. The length and width of the vortex street are about 60-70 km and 20 km, resp...

The current study examines the feasibility of placing a piezoelectric membrane or &&eel'' in the wake of a blu! body and using the von KaH rmaH n vortex street forming behind the blu! body to induce oscillations in the membrane. The oscillations result in a capacitive buildup in the membrane that provides a voltage source that can be used, for example, to trickle-charge a battery in a remote lo...

We consider streamline patterns associated with single and double von Kármán point vortex streets on the surface of a nonrotating sphere, with and without pole vortices. The full family of streamline patterns are identified and the topological bifurcations from one pattern to another are depicted as a function of latitude and pole strength. The process involves first finding appropriate vortex ...