Spontaneous aggregation and global polar ordering in squirmer suspensions

TL;DR

This paper uses numerical simulations to study how hydrodynamic stresses in active particle suspensions influence collective behavior, revealing that active stresses can lead to aggregation and order, especially in contractile squirmers.

Contribution

It introduces a Lattice Boltzmann simulation framework to analyze the impact of hydrodynamic stresses on collective dynamics in squirmer suspensions, highlighting the role of active stresses in structure formation.

Findings

Active stresses decorrelate collective motion.

Contractile squirmers form significant aggregates.

Hydrodynamic interactions influence global order.

Abstract

We have developed numerical simulations of three dimensional suspensions of active particles to characterize the capabilities of the hydrodynamic stresses induced by active swimmers to promote global order and emergent structures in active suspensions. We have considered squirmer suspensions embedded in a fluid modeled under a Lattice Boltzmann scheme. We have found that active stresses play a central role to decorrelate the collective motion of squirmers and that contractile squirmers develop significant aggregates.