8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

P10.36Tue 611:23-14:00Anomalous turbulence in bacterial suspensionsRik Wensink 11 Insitute for Theoretical Physics: Soft Matter, Heinrich-Heine-University-Düsseldorf,Universitätsstraße 1, 40225 Düesseldorf, GermanyTurbulent phases arise in a wide variety of physical and biological systems. Unfortunately, acomprehensive mathematical characterization of turbulence in complex fluids proves notoriouslydifficult due to the complexity of the underlying interactions and transport processes. In particular,it is not yet fully understood which features of turbulent states are universal or system dependent.Here, we find that the statistical properties of turbulent states in bacterial suspensions are distinctlydifferent from those in conventional high-Reynolds number flow, both in simulation and experiments.We observe that the asymptotic exponents of the longitudinal velocity structure functions ina dense Bacillus subtilis suspensions do not exhibit the Kolmogorov-Kraichnan scaling of standardturbulence, but instead agree qualitatively with predictions obtained from a minimal self-propelledrod model.36