Complex dynamics of knotted filaments in shear flow

Coarse-grained simulations are used to demonstrate that knotted filaments in shear flow at zero Reynolds number exhibit remarkably rich dynamic behaviour. For stiff filaments that are weakly deformed by the shear forces, the knotted filaments rotate like rigid objects in the flow. But away from this regime the interplay between between shear forces and the flexibility of the filament leads to intricate regular and chaotic modes of motion that can be divided into distinct families. The set of accessible mode families depends to first order on a dimensionless number that relates the filament length, the elastic modulus, the friction per unit length and the shear rate.