Spontaneous mirror-symmetry breaking induces inverse energy cascade in 3D active fluids
Name
Spontaneous mirror-symmetry breaking induces inverse energy cascade in 3D active fluids
Size
5.83 MB
Format
Unknown
Checksum (MD5)
30d7850e766431a395ee1297bc4f233d
Author(s)
Slomka, Jonasz Jozef
Dunkel, Joern
Date Issued
February 2017
Journal
Proceedings of the National Academy of Sciences
Publisher
National Academy of Sciences (U.S.)
Citation
Słomka, Jonasz and Dunkel, Jörn. “Spontaneous Mirror-Symmetry Breaking Induces Inverse Energy Cascade in 3D Active Fluids.” Proceedings of the National Academy of Sciences 114, 9 (February 2017): 2119–2124 © 2017 National Academy of Sciences
Version
Final published version
Abstract
Classical turbulence theory assumes that energy transport in a 3D turbulent flow proceeds through a Richardson cascade whereby larger vortices successively decay into smaller ones. By contrast, an additional inverse cascade characterized by vortex growth exists in 2D fluids and gases, with profound implications for meteorological flows and fluid mixing. The possibility of a helicitydriven inverse cascade in 3D fluids had been rejected in the 1970s based on equilibrium-thermodynamic arguments. Recently, however, it was proposed that certain symmetry-breaking processes could potentially trigger a 3D inverse cascade, but no physical system exhibiting this phenomenon has been identified to date. Here, we present analytical and numerical evidence for the existence of an inverse energy cascade in an experimentally validated 3D active fluid model, describing microbial suspension flows that spontaneously break mirror symmetry. We show analytically that self-organized scale selection, a generic feature of many biological and engineered nonequilibrium fluids, can generate parityviolating Beltrami flows. Our simulations further demonstrate how active scale selection controls mirror-symmetry breaking and the emergence of a 3D inverse cascade.
MIT Department
Massachusetts Institute of Technology. Department of Mathematics
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
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DOI of Published Version
https://doi.org/10.1073/PNAS.1614721114
