Rheology of active polar emulsions: from linear to unidirectional and unviscid flow, and intermittent viscosity

Abstract

The rheological behaviour of an emulsion made of an active polar component and an isotropic passive fluid is studied by lattice Boltzmann methods. Different flow regimes are found by varying the values of shear rate and extensile activity (occurring, e.g., in microtubule-motor suspensions). By increasing activity, a first transition occurs from linear flow regime to spontaneous persistent unidirectional macro-scale flow, followed by another transition either to (low shear) intermittent flow regime with coexistence of states with positive, negative, and vanishing apparent viscosity, or to (high shear) symmetric shear thinning regime. The different behaviours can be explained in terms of the dynamics of the polarization field close to the walls. A maximum entropy production principle selects the most likely states in the intermittent regime.

References in corpus (12)

• Motility-Induced Phase Separation
• Spontaneous motion in hierarchically assembled active matter
• Physics of Microswimmers - Single Particle Motion and Collective Behavior
• Meso-scale turbulence in living fluids
• Turning bacteria suspensions into a "superfluid"
• Defect dynamics in active nematics
• Shearing active gels close to the isotropic-nematic transition
• A minimal physical model captures the shapes of crawling cells
• Motility-induced phase separation and coarsening in active matter
• Sheared active fluids: thickening, thinning and vanishing viscosity
• Morphology and flow patterns in highly asymmetric active emulsions
• Chaotic and periodical dynamics of active chiral droplets

Cited by in corpus (11)

• Discrete Boltzmann multi-scale modeling of non-equilibrium multiphase flows
• Cascade or not cascade? Energy transfer and elastic effects in active nematics
• Yield-stress transition in suspensions of deformable droplets
• Hydrodynamic effects on the liquid-hexatic transition of active colloids
• Rheology of active emulsions with negative effective viscosity
• Activity induced isotropic-polar transition in active liquid crystals
• Coupling Turing stripes to active flows
• Entropy production of active Brownian particles going from liquid to hexatic and solid phases
• Dynamics of polydisperse multiple emulsions in microfluidic channels
• Lattice Boltzmann modeling of cholesteric liquid crystal droplets under an oscillatory electric field
• Motility and self propulsion of active droplets