Getting trapped in low-Re turbulence and collaborating your way out

We present an efficient numerical method to compute the dynamics of thousands of self-motile rod-like micro-swimmers that interact directly via the fluid flow they collectively generate. Using this method, we study the dynamics of rod-like swimmer particles in a background cellular vortical flow and show that hydrodynamic and steric interactions, the number of swimmers and system size, as well as the swimming mechanism (``Pusher'' vs. ``Puller''), have an effect on whether the swimmers get trapped in vortices or can escape them.