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Patterns and flow in frictional fluid dynamics.

Sandnes B, Flekkøy EG, Knudsen HA, Måløy KJ, See H - Nat Commun (2011)

Bottom Line: Here we consider Coulomb friction and compressibility in the fluid dynamics, and discover surprising responses including highly intermittent flow and a transition to quasi-continuous dynamics.Moreover, by varying the injection rate over several orders of magnitude, we characterize new dynamic modes ranging from stick-slip bubbles at low rate to destabilized viscous fingers at high rate.We classify the fluid dynamics into frictional and viscous regimes, and present a unified description of emerging morphologies in granular mixtures in the form of extended phase diagrams.

View Article: PubMed Central - PubMed

Affiliation: School of Chemical and Biomolecular Engineering, University of Sydney, Sydney, New South Wales 2006, Australia. bjornar.sandnes@fys.uio.no

ABSTRACT
Pattern-forming processes in simple fluids and suspensions have been studied extensively, and the basic displacement structures, similar to viscous fingers and fractals in capillary dominated flows, have been identified. However, the fundamental displacement morphologies in frictional fluids and granular mixtures have not been mapped out. Here we consider Coulomb friction and compressibility in the fluid dynamics, and discover surprising responses including highly intermittent flow and a transition to quasi-continuous dynamics. Moreover, by varying the injection rate over several orders of magnitude, we characterize new dynamic modes ranging from stick-slip bubbles at low rate to destabilized viscous fingers at high rate. We classify the fluid dynamics into frictional and viscous regimes, and present a unified description of emerging morphologies in granular mixtures in the form of extended phase diagrams.

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Phase space.(a) Tentative phase diagram of morphologies in the ϕ−1−q plane extended to the ϕ=1 limit corresponding to a close-packed porous medium. Various displacement morphologies in the frictional fluid give way to fracturing at ϕ>0.9, followed by a transition to capillary/viscous fingering in porous media (ϕ≈1).The phase boundaries are 'guides to the eye'. The images of capillary and viscous fingering in porous media have been obtained using different experimental setups by other authors3842. (b) A framework for displacement dynamics in frictional fluids illustrating the transitions between intermittent frictional, quasi-continuous frictional and continuous viscous fluid dynamics.
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f5: Phase space.(a) Tentative phase diagram of morphologies in the ϕ−1−q plane extended to the ϕ=1 limit corresponding to a close-packed porous medium. Various displacement morphologies in the frictional fluid give way to fracturing at ϕ>0.9, followed by a transition to capillary/viscous fingering in porous media (ϕ≈1).The phase boundaries are 'guides to the eye'. The images of capillary and viscous fingering in porous media have been obtained using different experimental setups by other authors3842. (b) A framework for displacement dynamics in frictional fluids illustrating the transitions between intermittent frictional, quasi-continuous frictional and continuous viscous fluid dynamics.

Mentions: As we extend the investigation to increasingly high filling fractions, the system changes characteristics from fluid- to solid-like behaviour. We find a transition to fracturing from approximately ϕ>0.9 (Fig. 5a), where the poorly compacted granular material can be described as a deformable, or weak, porous medium. Fracturing has previously been observed in viscoelastic fluids9 and density-matched suspensions of grains14. The industrial process of hydraulic fracturing is commonly used in oil reservoir engineering3637. Note, however, that this typically involves the injection under high pressure of a fracturing fluid with low compressibility, such that the elastic response originates mainly from the in situ medium.


Patterns and flow in frictional fluid dynamics.

Sandnes B, Flekkøy EG, Knudsen HA, Måløy KJ, See H - Nat Commun (2011)

Phase space.(a) Tentative phase diagram of morphologies in the ϕ−1−q plane extended to the ϕ=1 limit corresponding to a close-packed porous medium. Various displacement morphologies in the frictional fluid give way to fracturing at ϕ>0.9, followed by a transition to capillary/viscous fingering in porous media (ϕ≈1).The phase boundaries are 'guides to the eye'. The images of capillary and viscous fingering in porous media have been obtained using different experimental setups by other authors3842. (b) A framework for displacement dynamics in frictional fluids illustrating the transitions between intermittent frictional, quasi-continuous frictional and continuous viscous fluid dynamics.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3104512&req=5

f5: Phase space.(a) Tentative phase diagram of morphologies in the ϕ−1−q plane extended to the ϕ=1 limit corresponding to a close-packed porous medium. Various displacement morphologies in the frictional fluid give way to fracturing at ϕ>0.9, followed by a transition to capillary/viscous fingering in porous media (ϕ≈1).The phase boundaries are 'guides to the eye'. The images of capillary and viscous fingering in porous media have been obtained using different experimental setups by other authors3842. (b) A framework for displacement dynamics in frictional fluids illustrating the transitions between intermittent frictional, quasi-continuous frictional and continuous viscous fluid dynamics.
Mentions: As we extend the investigation to increasingly high filling fractions, the system changes characteristics from fluid- to solid-like behaviour. We find a transition to fracturing from approximately ϕ>0.9 (Fig. 5a), where the poorly compacted granular material can be described as a deformable, or weak, porous medium. Fracturing has previously been observed in viscoelastic fluids9 and density-matched suspensions of grains14. The industrial process of hydraulic fracturing is commonly used in oil reservoir engineering3637. Note, however, that this typically involves the injection under high pressure of a fracturing fluid with low compressibility, such that the elastic response originates mainly from the in situ medium.

Bottom Line: Here we consider Coulomb friction and compressibility in the fluid dynamics, and discover surprising responses including highly intermittent flow and a transition to quasi-continuous dynamics.Moreover, by varying the injection rate over several orders of magnitude, we characterize new dynamic modes ranging from stick-slip bubbles at low rate to destabilized viscous fingers at high rate.We classify the fluid dynamics into frictional and viscous regimes, and present a unified description of emerging morphologies in granular mixtures in the form of extended phase diagrams.

View Article: PubMed Central - PubMed

Affiliation: School of Chemical and Biomolecular Engineering, University of Sydney, Sydney, New South Wales 2006, Australia. bjornar.sandnes@fys.uio.no

ABSTRACT
Pattern-forming processes in simple fluids and suspensions have been studied extensively, and the basic displacement structures, similar to viscous fingers and fractals in capillary dominated flows, have been identified. However, the fundamental displacement morphologies in frictional fluids and granular mixtures have not been mapped out. Here we consider Coulomb friction and compressibility in the fluid dynamics, and discover surprising responses including highly intermittent flow and a transition to quasi-continuous dynamics. Moreover, by varying the injection rate over several orders of magnitude, we characterize new dynamic modes ranging from stick-slip bubbles at low rate to destabilized viscous fingers at high rate. We classify the fluid dynamics into frictional and viscous regimes, and present a unified description of emerging morphologies in granular mixtures in the form of extended phase diagrams.

Show MeSH
Related in: MedlinePlus