Departmental Papers (MEAM)

Stretching fields and mixing near the transition to nonperiodic two-dimensional flow

M. J. Twardos, Los Alamos National Laboratory
Paulo E. Arratia, University of Pennsylvania
M. K. Rivera, Haverford College
G. A. Voth, Wesleyan University
Jerry P. Gollub, Haverford College
R. E. Ecke, Los Alamos National Laboratory

Document Type Journal Article

Copyright American Physical Society. Reprinted from Physical Review E, Volume 77, Article No. 056315, May 2008.
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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.


Date Posted: 16 July 2008

This document has been peer reviewed.