Active nematic defects in compressible and incompressible flows

Abstract

We study the dynamics of active nematic films on a substrate driven by active flows with or without the incompressible constraint.Through simulations and theoretical analysis, we show that arch patterns are stable in the compressible case, whilst they become unstable under the incompressibility constraint. For compressible flows at high enough activity, stable arches organize themselves into a smectic-like pattern, which induce an associated global polar ordering of $+1/2$ nematic defects. By contrast, divergence-free flows give rise to a local nematic order of the $+1/2$ defects, consisting of anti-aligned pairs of neighboring defects, as established in previous studies.

10 pages, 4 figures

References in corpus (7)

• Spontaneous motion in hierarchically assembled active matter
• Topology and Dynamics of Active Nematic Vesicles
• Active Turbulence
• Defect dynamics in active nematics
• Sheared active fluids: thickening, thinning and vanishing viscosity
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Cited by in corpus (2)

• Phase Ordering in Binary Mixtures of Active Nematic Fluids
• Defect configuration of an active nematic around a circular obstacle