Fluid dynamics of bacterial turbulence
Abstract
Self-sustained turbulent structures have been observed in a wide range of living fluids, yet no quantitative theory exists to explain their properties. We report experiments on active turbulence in highly concentrated 3D suspensions of Bacillus subtilis and compare them with a minimal fourth-order vector-field theory for incompressible bacterial dynamics. Velocimetry of bacteria and surrounding fluid, determined by imaging cells and tracking colloidal tracers, yields consistent results for velocity statistics and correlations over two orders of magnitude in kinetic energy, revealing a decrease of fluid memory with increasing swimming activity and linear scaling between energy and enstrophy. The best-fit model parameters allow for quantitative agreement with experimental data.
Cite
@article{arxiv.1302.5277,
title = {Fluid dynamics of bacterial turbulence},
author = {Jörn Dunkel and Sebastian Heidenreich and Knut Drescher and Henricus H. Wensink and Markus Bär and Raymond E. Goldstein},
journal= {arXiv preprint arXiv:1302.5277},
year = {2013}
}
Comments
5 pages, 4 figures