ArticleTwardos MJ, Arratia PE, Rivera MK, Voth GA, Gollub JP, Ecke RE.
Phys Rev E Stat Nonlin Soft Matter Phys. 2008 May;77(5 Pt 2):056315.
Although time-periodic fluid flows sometimes produce mixing via Lagrangian chaos, the additional contribution to mixing caused by nonperiodicity has not been quantified experimentally. Here, we do so for a quasi-two-dimensional flow generated by electromagnetic forcing. Several distinct measures of mixing are found to vary continuously with the Reynolds number, with no evident change in magnitude or slope at the onset of nonperiodicity. Furthermore, the scaled probability distributions of the mean Lyapunov exponent have the same form in the periodic and nonperiodic flow states.