TY - JOUR
T1 - Foam drainage on the microscale
T2 - I. Modeling flow through single Plateau borders
AU - Koehler, S. A.
AU - Hilgenfeldt, S.
AU - Stone, H. A.
N1 - Funding Information:
We thank V. Carrier, M. Durand, A. Kraynik, D. Langevin, M. Loewenberg, A. Saint-Jalmes, D. Weaire, and E. Weeks for useful discussions. The Harvard MRSEC and the Petroleum Research Fund (Grant 35926-AC9) are thanked for their support, as is the Netherlands Organization for Scientific Research (NWO).
PY - 2004/8/15
Y1 - 2004/8/15
N2 - The drainage of liquid through a foam involves flow in channels, also called Plateau borders, which generally are long and slender. We model this flow by assuming the flow is unidirectional, the shear is transverse to the flow direction, and the liquid/gas interfaces are mobile and characterized by a Newtonian surface viscosity, which does not depend on the shear rate. Numerical finite difference simulations are performed, and analytical approximations for the velocity fields inside the channels and the films that separate the bubbles are given. We compare the liquid flow rates through interior channels, exterior channels (i.e., channels contacting container walls) and films. We find that when the number of exterior channels is comparable to the number of interior channels, i.e., narrow container geometries, the exterior channels can significantly affect the dynamics of the drainage process. Even for highly mobile interfaces, the films do not significantly contribute to the drainage process, unless the amount of liquid in the films is within a factor of ten of the amount of liquid in the channels.
AB - The drainage of liquid through a foam involves flow in channels, also called Plateau borders, which generally are long and slender. We model this flow by assuming the flow is unidirectional, the shear is transverse to the flow direction, and the liquid/gas interfaces are mobile and characterized by a Newtonian surface viscosity, which does not depend on the shear rate. Numerical finite difference simulations are performed, and analytical approximations for the velocity fields inside the channels and the films that separate the bubbles are given. We compare the liquid flow rates through interior channels, exterior channels (i.e., channels contacting container walls) and films. We find that when the number of exterior channels is comparable to the number of interior channels, i.e., narrow container geometries, the exterior channels can significantly affect the dynamics of the drainage process. Even for highly mobile interfaces, the films do not significantly contribute to the drainage process, unless the amount of liquid in the films is within a factor of ten of the amount of liquid in the channels.
KW - Emulsions
KW - Foams
KW - Surface rheology
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U2 - 10.1016/j.jcis.2003.12.061
DO - 10.1016/j.jcis.2003.12.061
M3 - Article
C2 - 15271571
AN - SCOPUS:3242723291
SN - 0021-9797
VL - 276
SP - 420
EP - 438
JO - Journal of Colloid And Interface Science
JF - Journal of Colloid And Interface Science
IS - 2
ER -