Title of article :
Viscous Fingering With Chemical Reaction: Effect Of In-Situ Production Of Surfactants
Author/Authors :
Fernandez، Juan نويسنده , , Homsy، G. M. نويسنده ,
Issue Information :
دوهفته نامه با شماره پیاپی سال 2003
Pages :
-266
From page :
267
To page :
0
Abstract :
Viscous fingering experiments are performed in a radial Hele-Shaw cell for a liquid-liquid system in the presence of a wellcharacterized interfacial reaction capable of changing the surface tension on the time scale of the experiments. The reaction is a neutralization of a fatty acid by an alkaline material to form a surfactant, which exhibits first-order kinetics for the surface tension as a function of time. The experiments are carried out for capillary numbers, Ca, high enough for the fingering to always be in the fractal regime, and for a wide range of Damk?hler numbers, Da. The fingers are typically wider in the presence of the chemical reaction than the non-reactive case. We observe two different-behaviours of the reactive fingering patterns. For intermediate values of Da, 0.5 < Da < 4, the fractal dimension d_{f} is higher than the classical value measured for the non-reactive fingering patterns and reaches a maximum of about 1.9. For both small (Da < 0.5) and high Da (Da > 4), the reactive fingering patterns are similar to the fingers with no reaction: the fractal dimension is found to be the same for both systems. These effects are consistent with the hypothesis that Marangoni stresses are present and produce wider fingers.
Keywords :
conditional temporal moments , multirate sorption , groundwater , heterogeneity , reactive transport
Journal title :
Journal of Fluid Mechanics
Serial Year :
2003
Journal title :
Journal of Fluid Mechanics
Record number :
79810
Link To Document :
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