We study a novel phase of active polar fluids, which is characterized by the continuous creation and destruction of dense clusters due to self-sustained turbulence. This state arises due to the interplay of the self-advection of the aligned swimmers and their defect topology. The typical cluster size is determined by the characteristic vortex size. Our results are obtained by investigating a continuum model of compressible polar active fluids, which incorporates typical experimental observations in bacterial suspensions by assuming a non-monotone dependence of speed on density.
@article{arxiv.2107.07588,
title = {Turbulence-induced clustering in compressible active fluids},
author = {Vasco M. Worlitzer and Gil Ariel and Avraham Be'er and Holger Stark and Markus Bär and Sebastian Heidenreich},
journal= {arXiv preprint arXiv:2107.07588},
year = {2022}
}