A Chaotic Periodically Reoriented Irrotational Flow: Experiments, Theory, and Applications to Geophysical Transport

A source-sink pair in a Hele-Shaw cell generates an irrotational dipole flow. In a disk with 360 wells around its periphery and a rotatable manifold controlling which well pairs are open, we have created a periodically reoriented dipole flow which is an open chaotic dynamical system with properties controlled by the reorientation angle and duration of flow. Despite being open the flow can have island regions where fluid that starts in the disk remains there forever. Theory and experiments determine the island existence boundary in control parameter space, the variation in island size, and bifurcations. We also briefly describe possible applications to problems in geophysical transport.