Numerical simulations of a minimal model for the fluid dynamics of dense bacterial suspensions

Abstract

Collective behavior is a fascinating phenomenon and ubiquitous in nature. A large variety of complex dynamic structures from swarming to turbulence arise in active particle systems. In recent investigations a set of minimal continuum equations was proposed to model mesoscale bacterial turbulence. Numerical solutions are validated with experimental data of Bacillus subtilis bacteria. In this short paper we present a recently used pseudo-spectral operator splitting method that directly solves the nonlinear equations in the turbulent regime. In two and three spatial dimensions we show the resulting typical velocity and vorticity fields as well as energy spectra to highlight the strong difference between turbulence in ordinary fluids and in bacterial suspensions. © Published under licence by IOP Publishing Ltd.