Side branched patterns, coalescence and stable interfaces during radial displacement of a viscoelastic fluid

We explore the interfacial instability that results when a Newtonian fluid (a glycerol-water mixture, inner fluid) displaces a viscoelastic fluid (a dense cornstarch suspension, outer fluid) in a radial Hele-Shaw cell. As the ratio of viscosities of the inner and outer fluids is increased, side bran...

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Bibliographic Details
Published in:arXiv.org 2020-10
Main Authors: Palak, Sathyanath, Rahul, Kalpathy, Sreeram K, Bandyopadhyay, Ranjini
Format: Article
Language:English
Subjects:
Coalescing
Computational fluid dynamics
Displacement
Fluids
Glycerol-Water
Interface stability
Mathematical models
Newtonian fluids
Viscoelastic fluids
Viscoelasticity
Viscosity ratio
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Summary:We explore the interfacial instability that results when a Newtonian fluid (a glycerol-water mixture, inner fluid) displaces a viscoelastic fluid (a dense cornstarch suspension, outer fluid) in a radial Hele-Shaw cell. As the ratio of viscosities of the inner and outer fluids is increased, side branched interfacial patterns are replaced by more stable interfaces that display proportionate growth and finger coalescence. We correlate the average finger spacing with the most dominant wavelength of interfacial instability, computed using a mathematical model that accounts for viscous fingering in miscible Hele-Shaw displacements. The model predictions on the role of viscosity ratio on finger spacing are in close agreement with the experimental observations. Our study lends insight into the significant contribution of the viscoelasticity of the outer fluid on the morphology and growth of interfacial patterns.
ISSN:2331-8422
DOI:10.48550/arxiv.2010.10423