Experimental evidence of a helical, supercritical instability in pipe flow of shear thinning fluids

Picaut, Lise; Ronsin, Olivier; Caroli, C.; Baumberger, Tristan

doi:10.1103/physrevfluids.2.083303

Cited by 9 publications

(14 citation statements)

References 26 publications

(43 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2015; Poole 2016; Picaut et al. 2017; Chandra et al. 2019) in channel/tube flows of highly shear-thinning concentrated solutions (), but these observations cannot be explained by the centre-mode instability which is absent for .…”

Section: Neutral Stability Curvesmentioning

confidence: 99%

The centre-mode instability of viscoelastic plane Poiseuille flow

et al. 2021

View full text Add to dashboard Cite

show abstract

Section: Neutral Stability Curvesmentioning

confidence: 99%

The centre-mode instability of viscoelastic plane Poiseuille flow

et al. 2021

View full text Add to dashboard Cite

show abstract

“…Aqueous alginate solutions exhibit shear thinning while the viscosity depends on the polymer concentration, its molecular weight and the polymer composition [128,129].…”

Section: Natural Saps Based On Alginate and Its Derivativesmentioning

confidence: 99%

Superabsorbent polymers: A review on the characteristics and applications of synthetic, polysaccharide-based, semi-synthetic and ‘smart’ derivatives

Mignon

Belie

Dubruel

et al. 2019

European Polymer Journal

189

108

View full text Add to dashboard Cite

The current review provides an overview of different types of superabsorbent polymers (SAPs) together with appropriate strategies elaborated to enable their synthesis. The main focus will be on polysaccharide-based, semi-synthetic and 'smart' SAPs along with their derivatives. SAPs have already shown their use in a plethora of applications including diapers, the biomedical field, agriculture, etc.The different polymer classification possibilities are discussed, as well as the classification of the constituting building blocks. The main part of SAPs still has a synthetic origin. However, as they are often not biocompatible, biodegradable or renewable, natural SAPs based on polysaccharides have gained increasing interest. Due to the low solubility of synthetic polymers, purification problems or the need for organic solvents, a trend has emerged towards combining polysaccharides with synthetic monomers to create semi-synthetic, hybrid SAPs for specialized applications with fine-tuned properties including wound dressings, fertilizers or self-healing concrete. These specialized, semi-synthetic SAPs offer strong potential for a series of applications in the future. However, future research in this respect is still needed to optimize homogeneity and to increase gel fractions. A final part of this review includes 'smart' SAPs such as SAPs with a T-, electro-and pH-sensitivity. These 'smart' SAPs are especially becoming useful for certain biomedical applications such as drug release for which an in vivo location can be targeted. The use of 'smart', semi-synthetic SAPs with fine-tuned characteristics combining the best characteristics of both synthetic and natural SAPs, offer the greatest potential for the future.

show abstract

“…[17] and [18] respectively, but apparently at odds with instability having been observed for n = 0.30 in the experiments of Ref. [16].…”

Section: Criterion For Instability Onsetmentioning

confidence: 82%

Linear instability of shear thinning pressure driven channel flow

Barlow

Hemingway

Clarke

et al. 2019

Journal of Non-Newtonian Fluid Mechanics

View full text Add to dashboard Cite

We study theoretically pressure driven planar channel flow of shear thinning viscoelastic fluids. Combining linear stability analysis and full nonlinear simulation, we study the instability of an initially one-dimensional base state to the growth of two-dimensional perturbations with wavevector in the flow direction. We do so within three widely used constitutive models: the microscopically motivated Rolie-Poly model, and the phenomenological Johnson-Segalman and White-Metzner models. In each model, we find instability when the degree of shear thinning exceeds some level characterised by the logarithmic slope of the flow curve at its shallowest point, n = d log Σ/d logγ|min. Specifically, we find instability for n < n * , with n * ≈ 0.21, 0.11 and 0.30 in the Rolie-Poly, Johnson-Segalman and White-Metzner models respectively. Within each model, we show that the critical pressure drop for the onset of instability obeys a criterion expressed in terms of this degree of shear thinning, n, together with the derivative of the first normal stress with respect to shear stress. Both shear thinning and rapid variations in first normal stress across the channel are therefore key ingredients driving the instability. In the Rolie-Poly and Johnson-Segalman models, the underlying mechanism appears to involve the destabilisation of a quasi-interface that exists in each half of the channel, across which the normal stress varies rapidly. (The flow is not however shear banded in any parameter regime that we consider.) In the White-Metzner model, no such quasi-interface exists, but the criterion for instability nonetheless appears to follow the same form as in the Rolie-Poly and Johnson-Segalman models. This presents an outstanding puzzle concerning any possibly generic nature of the instability mechanism. We finally make some brief comments on the Giesekus model, which is rather different in its predictions from the other three. arXiv:1903.01910v3 [cond-mat.soft]

show abstract

Experimental evidence of a helical, supercritical instability in pipe flow of shear thinning fluids

Cited by 9 publications

References 26 publications

The centre-mode instability of viscoelastic plane Poiseuille flow

The centre-mode instability of viscoelastic plane Poiseuille flow

Superabsorbent polymers: A review on the characteristics and applications of synthetic, polysaccharide-based, semi-synthetic and ‘smart’ derivatives

Linear instability of shear thinning pressure driven channel flow

Contact Info

Product

Resources

About