Dynamic regimes of hydrodynamically coupled self-propelling particles

TL;DR

This paper investigates the collective behavior of self-propelling particles at low Reynolds numbers, highlighting how hydrodynamic interactions influence their motion, structure formation, and transition from diffusive to ballistic regimes.

Contribution

It provides a numerical analysis of hydrodynamically coupled self-propelling particles, revealing non-Gaussian velocity distributions and dynamic phase transitions.

Findings

Velocity distributions deviate from Gaussian at short times

Mean-square displacement transitions from diffusive to ballistic at long times

Particle structures correlate with dynamic behavior

Abstract

We analyze the collective dynamics of self-propelling particles (spps) which move at small Reynolds numbers including the hydrodynamic coupling to the suspending solvent through numerical simulations. The velocity distribution functions show marked deviations from Gaussian behavior at short times, and the mean-square displacement at long times shows a transition from diffusive to ballistic motion for appropriate driving mechanism at low concentrations. We discuss the structures the spps form at long times and how they correlate to their dynamic behavior.