Ordering kinetics in active polar fluid

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 the system shows the good dynamic scaling for all activities. Our study provides the understanding of ordering kinetics in active polar gel.