Mixing measures for a two-dimensional chaotic Stokes flow

The effectiveness of a large number of protocols for mixing in a two-dimensional chaotic Stokes flow, according to a variety of measures, is investigated. The degree to which the various mixing measures are correlated is computed, and while no single protocol simultaneously optimises all measures, it is found that a small subset of the protocols perform well against most measures. However, it is difficult to elicit general rules for selecting effective protocols: for example, superficially similar protocols are found to exhibit considerably different mixing capabilities. The results presented here suggest that the selection of effective protocols by 'sieving' (i.e., by successively eliminating candidate protocols that fail increasingly discerning mixing measures) may be ineffective in practice.