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Frictional Fluid Dynamics and Plug Formation in Multiphase Millifluidic Flow / Guillaume Dumazer, Bjornar Sandnes, Monem Ayaz, Knut Jørgen Måløy, Eirik Grude Flekkøy

Physical Review Letters, Volume: 117, Issue: 2

Swansea University Author: Bjornar Sandnes

Abstract

We study experimentally the flow and patterning of a granular suspension displaced by air inside a narrow tube. The invading air-liquid interface accumulates a plug of granular material that clogs the tube due to friction with the confining walls. The gas percolates through the static plug once the...

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Published in: Physical Review Letters
ISSN: 0031-9007 1079-7114
Published: 2016
Online Access: Check full text

URI: https://cronfa.swan.ac.uk/Record/cronfa28884
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Abstract: We study experimentally the flow and patterning of a granular suspension displaced by air inside a narrow tube. The invading air-liquid interface accumulates a plug of granular material that clogs the tube due to friction with the confining walls. The gas percolates through the static plug once the gas pressure exceeds the pore capillary entry pressure of the packed grains, and a moving accumulation front is reestablished at the far side of the plug. The process repeats, such that the advancing interface leaves a trail of plugs in its wake. Further, we show that the system undergoes a fluidization transition—and complete evacuation of the granular suspension—when the liquid withdrawal rate increases beyond a critical value. An analytical model of the stability condition for the granular accumulation predicts the flow regime.
Keywords: Frictional fluids, pattern formation, conveying, plug formation, multiphase flow, granular materials, complex flow
College: College of Engineering
Issue: 2