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Titel |
Flow of a two-dimensional aqueous foam in two parallel channels |
VerfasserIn |
S. Jones, I. Cantat, B. Dollet, Y. Méheust |
Konferenz |
EGU General Assembly 2012
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Medientyp |
Artikel
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Sprache |
Englisch
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Digitales Dokument |
PDF |
Erschienen |
In: GRA - Volume 14 (2012) |
Datensatznummer |
250070696
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Zusammenfassung |
Flowing foams are used in many engineering and technical applications. A well-known
application is oil recovery. Another one is the remediation of polluted soil: the foam is
injected into the ground in order to mobilize chemical species that are initially present in the
medium. Apart from potential interesting physico-chemical and biochemical properties,
foams have pecular flow properties that might be used in order to reach regions of the
medium that are normally the least permeable. We study here this physical aspect of the
topic.
As a precursor to the study of foam flow through a complex porous material, we study the
behaviour of an aqueous two-dimensional foam flowing through a medium consisting of two
parallel channels with different widths, at fixed medium porosity, that is, at fixed total
combined width of the two channels. The flow velocity, and hence flux, in each channel is
measured by analyzing images of the flowing foam. The corresponding pressure drop
along each channel is calculated based on theoretical arguments involving both (i) a
dynamic pressure drop, which is controlled by bubble–wall friction, and (ii) possibly a
capillary pressure drop over the bubble films that emerge at the channel outlet,
the latter pressure drop being controlled by the radius of curvature of the bubble
film.
The flow behaviour of the foam happens to not uniquely be determined by the channel
width, as would be the case for a Newtonian fluid, but also to be highly dependent on the
foam structure within the narrowest of the two channel, especially when a “bamboo”
structure is obtained. Consequently, the flux in a channel is found to have a more complicated
relation to the channel width than expected. We try to define a corresponding medium
permeability and compare it to the permeability expected for the flow of a standard newtonian
fluid in the same geometry. |
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