Three-dimensional mesoscale turbulence in bacterial suspensions

Abstract:

Self-sustained turbulent motion of bacterial suspensions presents an intriguing example for collective nonlinear behavior in biological systems, and is thought to be important for fluid mixing. The mathematical characterization of the flow dynamics in active non-equilibrium fluids proves even more difficult than for conventional liquids and a quantitative theoretical description is still missing.
In the present talk, I summarize recent theoretical and experimental work of 3D bacterial turbulence. In particular, a forth-order partial differential equation with a Navier-Stokes type nonlinearity is introduced, motivated and numerically solved. From turbulent pattern characteristic quantities, e.g. structure functions and energy scaling, are calculated and compared with experimental data of Bacilus subtilis suspensions.