Spontaneous flow instabilities of active polar fluids in three dimensions
arXiv:2302.04259 · doi:10.1103/PhysRevResearch.5.L022061
Abstract
Active polar fluids exhibit spontaneous flow when sufficient active stress is generated by internal molecular mechanisms. This is also referred to as an active Fréedericksz transition. Experiments have revealed the existence of competing in-plane and out-of-plane instabilities in three-dimensional active matter. So far, however, a theoretical model reconciling all observations is missing. In particular, the role of boundary conditions in these instabilities still needs to be explained. Here, we characterize the spontaneous flow transition in a symmetry-preserving three-dimensional active Ericksen-Leslie model, showing that the boundary conditions select the emergent behavior. Using nonlinear numerical solutions and linear perturbation analysis, we explain the mechanism for both in-plane and out-of-plane instabilities under extensile active stress for perpendicular polarity anchoring at the boundary, whereas parallel anchoring only permits in-plane flows under contractile stress or out-of-plane wrinkling under extensile stress.
References in corpus (11)
- Generic theory of active polar gels: a paradigm for cytoskeletal dynamics
- Confinement Stabilizes a Bacterial Suspension into a Spiral Vortex
- Topological active matter
- Spontaneous flow transition in active polar gels
- Spontaneous Circulation of Confined Active Suspensions
- Confinement controlled bend instability of three-dimensional active fluids
- OpenFPM: A scalable open framework for particle and particle-mesh codes on parallel computers
- Confinement-induced Self-Pumping in 3D Active Fluids
- Flow states and transitions of an active nematic in a three dimensional channel
- Wrinkling instability in 3D active nematics
- Active extensile stress promotes 3D director orientations and flows