Conference Paper/Proceeding/Abstract 785 views
Gravity Induced Ordering of Frictional Fingers
Geophysical Research Abstracts 16, EGU2014-14715., Volume: 16
Swansea University Author: Bjornar Sandnes
Experiments on confined two-phase flow systems, involving air and adense suspension, have revealed highly non-trivial flowmorphologies. As the air displaces the suspension, the grains thatmake up the suspension tend to accumulate along the interface, and canbuild up force chains that jam the accumul...
|Published in:||Geophysical Research Abstracts 16, EGU2014-14715.|
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Experiments on confined two-phase flow systems, involving air and adense suspension, have revealed highly non-trivial flowmorphologies. As the air displaces the suspension, the grains thatmake up the suspension tend to accumulate along the interface, and canbuild up force chains that jam the accumulated region. This dynamicswill generate "frictional fingers" of air coated by a region ofdensely packed grains. The fingers have a characteristic width thatbalances surface tension and frictional forces of the densely packedgrains. When these fingers grow under the influence of gravity, theycan align either horizontally or vertically, or grow in a randomisotropic fashion. The transition between the different modes offinger growth depends on the density of grains, and the gravitationalforce component. We present an analytic model to account for thetransitions between the modes. We further present a numerical schemethat enables us to simulate the dynamics of the process. The numericaland analytic results are in good agreements with the experimentalfindings.Finally we show how this process could explain patterns that emergenaturally in early stages of dyke formation. These patterns areformed when hot fluid displaces partly molten rocks and packs the hardmineral grains composing it together, thereby forming fingerstructures that remain frozen in the dyke walls.
Pattern formation, Frictional fluids, gravity, frictional fingers
Faculty of Science and Engineering