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arXiv · 1710.01956

Vortex dynamics and Lagrangian statistics in a model for active turbulence

Martin James·Michael Wilczek
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Abstract

Cellular suspensions such as dense bacterial flows exhibit a turbulence-like phase under certain conditions. We study this phenomenon of "active turbulence" statistically by using numerical tools. Following Wensink et al. [Proc. Natl. Acad. Sci. U.S.A. 109, 14308 (2012)], we model active turbulence by means of a generalized Navier-Stokes equation. Two-point velocity statistics of active turbulence, both in the Eulerian and the Lagrangian frame, is explored. We characterize the scale-dependent features of two-point statistics in this system. Furthermore, we extend this statistical study with measurements of vortex dynamics in this system. Our observations suggest that the large-scale statistics of active turbulence is close to Gaussian with sub-Gaussian tails.

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Martin James, Michael Wilczek. 2017-10-05. Vortex dynamics and Lagrangian statistics in a model for active turbulence. https://doi.org/10.1140/epje%2Fi2018-11625-8

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