Poiseuille flow of soft polycrystals in 2D rough channels
arXiv:1809.02068 · doi:10.1103/PhysRevLett.124.158003
Abstract
Polycrystals are partially ordered solids where crystalline order extends over mesoscopic length scales, namely, the grain size. We study the Poisuielle flow of such materials in a rough channel. In general, similar to yield stress fluids, three distinct dynamical states, namely, flowing, stick-slip and jammed can be observed, with a yield threshold dependent on channel width. Importantly, the interplay between the finite channel width, and the intrinsic ordering scale (the grain size) leads to new type of spatiotemporal heterogeneity. In wide channels, although the average flow profile remains plug like, at the underlying granular level, there is vigorous grain remodelling activity resulting from the velocity heterogeneity among the grains. As the channel width approaches typical grain size, the flowing polycrystalline state breaks up into a spatially heterogeneous mixture of flowing liquid like patches and chunks of nearly static grains. Despite these static grains, the average velocity still shows a parabolic profile, dominated by the moving liquid like patches. However, the solid-liquid front moves at nearly constant speed in the opposite direction of the external drive.
References in corpus (12)
- A kinetic theory of plastic flow in soft glassy materials
- Jamming, two-fluid behaviour and 'self-filtration' in concentrated particulate suspensions
- Velocity oscillations in confined channel flows of concentrated colloidal suspensions
- Transitions among crystal, glass, and liquid in a binary mixture with changing particle size ratio and temperature
- Velocity correlations in dense granular flows observed with internal imaging
- The statistics of particle velocities in dense granular flows
- Plastic deformations in crystal, polycrystal, and glass in binary mixtures under shear: Collective yielding
- Plasticity of a colloidal polycrystal under cyclic shear
- Self-Organized Velocity Pulses of Dense Colloidal Suspensions in Microchannel Flow
- Intermittent dislocation density fluctuations in crystal plasticity from a phase-field crystal model
- Poiseuille flow of soft glasses in narrow channels: From quiescence to steady state
- Profile blunting and flow blockage in a yield stress fluid: A molecular dynamics study