Physics

Channel (broadcasting)

Geology

Archaeology

Pure mathematics

Clogging

Mathematics

Mechanics

Suspension (topology)

Statistical physics

Statistics

Oceanography

Engineering

Embedded system

Geography

Silo

Particle (ecology)

Flow (mathematics)

Computer science

Bottleneck

Power law

Simulation

Homotopy

Telecommunications

Mechanical engineering

Physical review. E

When suspended particles are pushed by liquid flow through a constricted channel, they might either pass the bottleneck without trouble or encounter a permanent clog that will stop them forever. However, they may also flow intermittently with great sensitivity to the neck-to-particle size ratio $D/d$. In this Rapid Communication, we experimentally explore the limits of the intermittent regime for a dense suspension through a single bottleneck as a function of this parameter. To this end, we make use of high time- and space-resolution experiments to obtain the distributions of arrest times ($T$) between successive bursts, which display power-law tails ($\ensuremath{\propto}{T}^{\ensuremath{-}\ensuremath{\alpha}}$) with characteristic exponents. These exponents compare well with the ones found for as disparate situations as the evacuation of pedestrians from a room, the entry of a flock of sheep into a shed, or the discharge of particles from a silo. Nevertheless, the intrinsic properties of our system (i.e., channel geometry, driving and interaction forces, particle size distribution) seem to introduce a sharp transition from a clogged state ($\ensuremath{\alpha}\ensuremath{\le}2$) to a continuous flow, where clogs do not develop at all. This contrasts with the results obtained in other systems where intermittent flow, with power-law exponents above two, were obtained.

Transition from clogging to continuous flow in constricted particle suspensions