Role of Lobes in Chaotic Mixing of Miscible and Immiscible Impurities.

Experiments compare long-range chaotic mixing of miscible and immiscible impurities in a time-periodic flow. For the miscible case, the transport is enhanced diffusion with an effective diffusion constant determined by lobes (turnstiles) that carry impurities between vortices. For the immiscible case, the impurity is broken into a distribution of droplets. If the characteristic droplet size is appreciably smaller than the lobe size, the transport is equivalent to that from the miscible case. Otherwise, interfacial tension results in reduction (and possibly extinction) of the transport. [S0031-9007(96)01248-3]