Speaker
Description
The dynamic behavior of a self-propelled semiflexible filament of length L is con-
sidered under the action of a linear shear flow. The system is studied by using
Brownian multi-particle collision dynamics. The system can be characterized in
terms of the persistence length Lp of the chain, of the Peclet number, and of
the Weissenberg number. The quantity Lp/L measures the bending rigidity of
the polymer, the Peclet number Pe is the ratio of active force times L to thermal
energy, and the Weissenberg number Wi characterizes the flow strength over thermal
effects. In this presentation we will focus our attention to intermediate values of
Pe corresponding to the weak spiral regime when no external flow is applied. The
numerical results allow us to outline the main features of the physics underlying the
considered system:
• At low values of Wi, polymer is stretched by activity and aligned by shear along
the flow direction. This effect is more marked in the case of more flexible
chains.
• At the intermediate values of Wi, polymer is prone to tumble due to shear and
this promotes a contraction of the chain.
• At very high values of Wi, activity sums up to shear enhancing polymer
stretching and deformation.
