Ordering kinetics in active polar fluid

TL;DR

This paper investigates the ordering kinetics in active polar fluids, revealing how activity type influences domain growth and morphology, with implications for understanding active gel dynamics.

Contribution

It introduces a model for active polar fluids incorporating active stresses and studies how activity affects growth kinetics and morphology.

Findings

Extensile activity enhances domain growth.

Contractile activity suppresses domain growth.

Growth becomes algebraic at high activity levels.

Abstract

We model the active polar fluid as a collection of orientable objects supplied with active stresses and momentum damping coming from the viscosity of bulk fluid medium. The growth kinetics of local orientation field is studied. The effect of active fluid is contractile or extensile depending upon the sign of the active stress. We explore the growth kinetics for different activities. We observe that for both extensile and contractile cases the growth is altered by a prefactor when compared to the equilibrium Model A. We find that the extensile fluid enhances the domain growth whereas the contractile fluid supresses it. The asymptotic growth becomes pure algebraic for large magnitudes of activity. We also find that the domain morphology remains unchanged due to activity and system shows the good dynamic scaling for all activities. Our study provides the understanding of ordering kinetics in active polar gel.