Boundaries control active channel flows
@inproceedings{Gulati2022BoundariesCA, title={Boundaries control active channel flows}, author={Paarth Gulati and Suraj Shankar and M. Cristina Marchetti}, booktitle={Frontiers in Physics}, year={2022} }
Boundary conditions dictate how fluids, including liquid crystals, flow when pumped through a channel. Can boundary conditions also be used to control internally driven active fluids that generate flows spontaneously? By using numerical simulations and stability analysis we explore how parallel surface anchoring of active agents at the boundaries and substrate drag can be used to rectify coherent flow of an active polar fluid in a 2D channel. Upon increasing activity, a succession of dynamical…
References
SHOWING 1-10 OF 66 REFERENCES
Flow transitions and length scales of a channel-confined active nematic.
- PhysicsSoft matter
- 2021
We perform lattice Boltzmann simulations of an active nematic fluid confined in a two-dimensional channel to study the range of flow states that are stabilised by the confinement: unidirectional…
Transition from turbulent to coherent flows in confined three-dimensional active fluids
- PhysicsScience
- 2017
It is demonstrated that 3D confinements and boundaries robustly transform turbulent-like dynamics of bulk active fluids into self-organized coherent macroscopic flows that persist on length scales ranging from micrometers to meters and time scales of hours.
Nonequilibrium steady states in polar active fluids
- Physics
- 2011
We study numerically the hydrodynamics of an active polar suspension, both in the absence and in the presence of an external shear. We focus on extensile fluids, which are models for bacterial…
Role of the active viscosity and self-propelling speed in channel flows of active polar liquid crystals.
- PhysicsSoft matter
- 2016
The numerical study demonstrates a strong correlation between the most unstable eigenfunction obtained from the linear analysis and the terminal steady state or the persistent, traveling wave structure, revealing the genesis of flow and orientational structures in the active matter system.
Directed collective motion of bacteria under channel confinement
- Physics
- 2016
Dense suspensions of swimming bacteria are known to exhibit collective behaviour arising from the interplay of steric and hydrodynamic interactions. Unconfined suspensions exhibit transient,…
Confinement-Induced Self-Pumping in 3D Active Fluids.
- PhysicsPhysical review letters
- 2020
The mechanism that is identified applies to a large class of symmetries and propulsion mechanisms, leading to a unified set of design principles for self-pumping 3D active fluids.
Dynamics and structure of an apolar active suspension in an annulus
- PhysicsJournal of Fluid Mechanics
- 2017
We study the complex dynamics of a two-dimensional suspension comprising non-motile active particles confined in an annulus. A coarse-grained liquid crystal model is employed to describe the nematic…
The geometry of thresholdless active flow in nematic microfluidics
- Physics
- 2016
"Active nematics" are orientationally ordered but apolar fluids composed of interacting constituents individually powered by an internal source of energy. When activity exceeds a system-size…
Exact Coherent Structures and Phase Space Geometry of Preturbulent 2D Active Nematic Channel Flow.
- PhysicsPhysical review letters
- 2022
Confined active nematics exhibit rich dynamical behavior, including spontaneous flows, periodic defect dynamics, and chaotic "active turbulence." Here, we study these phenomena using the framework of…
Hydrodynamics of confined active fluids.
- PhysicsPhysical review letters
- 2013
This work demonstrates that hydrodynamic interactions between confined swimmers depend solely on their shape and are independent of their specific swimming mechanism, and quantifies the consequences of these microscopic interaction rules on the large-scale hydrodynamics of isotropic populations.