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| Titel |
Gravity Induced Ordering of Frictional Fingers |
| VerfasserIn |
Jon Eriksen, Bjornar Sandnes, Renaud Toussaint, Knut Jørgen Måløy, Eirik Flekkøy |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250098982
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| Publikation (Nr.) |
 EGU/EGU2014-14715.pdf |
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| Zusammenfassung |
| Experiments on confined two-phase flow systems, involving air and a
dense suspension, have revealed highly non-trivial flow
morphologies. As the air displaces the suspension, the grains that
make up the suspension tend to accumulate along the interface, and can
build up force chains that jam the accumulated region. This dynamics
will generate "frictional fingers" of air coated by a region of
densely packed grains. The fingers have a characteristic width that
balances surface tension and frictional forces of the densely packed
grains. When these fingers grow under the influence of gravity, they
can align either horizontally or vertically, or grow in a random
isotropic fashion. The transition between the different modes of
finger growth depends on the density of grains, and the gravitational
force component. We present an analytic model to account for the
transitions between the modes. We further present a numerical scheme
that enables us to simulate the dynamics of the process. The numerical
and analytic results are in good agreements with the experimental
findings.
Finally we show how this process could explain patterns that emerge
naturally in early stages of dyke formation. These patterns are
formed when hot fluid displaces partly molten rocks and packs the hard
mineral grains composing it together, thereby forming finger
structures that remain frozen in the dyke walls. |
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