Mechanism of shear thickening in suspensions of rigid spheres in Boger fluids. Part I: Dilute suspensions

Two-body interactions of small rigid and deformable spheres in dilute suspensions undergoing Poiseuille flow at Reynolds numbers less than 10 –3 were studied and found to be similar to those previously observed in Couette flow. Two-body collisions between rigid spheres were symmetrical and reversible, the paths of approach and recession being curvilinear and mirror images of one another, except near the wall. The measured collision frequency agreed well with a theory based on rectilinear approach and recession, whereas the measured steady-state number of doublets was twice that predicted by the theory. The discrepancy was in part due to the existence of non-separating doublets, the orbits of which were also studied. In contrast, collisions between liquid drops were unsymmetrical, thus providing a mechanism for net migration of drops towards the tube axis in addition to the axial migration previously observed with single deformed drops.

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Effects of Matrix Viscoelasticity on Rheology of Dilute and Semi-Dilute Suspensions of Non Brownian Rigid Spheres

10.1063/1.2964825 ◽

2008 ◽

Author(s):

Nino Grizzuti ◽

Rossana Pasquino ◽

Albert Co ◽

Gary L. Leal ◽

Ralph H. Colby ◽

...

Keyword(s):

Rigid Spheres ◽

Dilute Suspensions

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Interrelationships of Particle Structure and Flow in Concentrated Suspensions

MRS Bulletin ◽

10.1557/s088376940005630x ◽

1991 ◽

Vol 16 (8) ◽

pp. 32-37 ◽

Cited By ~ 24

Author(s):

Richard L. Hoffman

Keyword(s):

Particle Concentration ◽

Flow Behavior ◽

Particle Interactions ◽

Particle Structure ◽

Concentrated Suspensions ◽

Rigid Spheres ◽

Classical Work ◽

Dilute Suspensions ◽

Polymer Dispersions ◽

Multiple Particle

Numerous commercial products either exist as concentrated suspensions of small particles or involve the processing of concentrated suspensions during some stage of their manufacture. Examples include foods, adhesives and glues, ceramic dispersions, paints, and polymer dispersions such as polyvinyl chloride plastisols. As a result, it is important for engineers to understand the flow behavior of these systems and how the flow behavior affects the way these materials can be processed.For mahy years, progress in understanding the flow behavior of concentrated suspensions was slow compared to progress on dilute systems, partly because of how the study of suspensions evolved. Building on Einstein's classical work for dilute suspensions of rigid spheres, many authors attempted to modify his equations to predict the flow behavior of more concentrated suspensions, but the extension of Einstein's work met with limited success, because nonhydrodynamic interactions cari be just as important as the hydrodynamic interactions considered by Einstein, and multiple particle interactions quickly complicate the problem as the particle concentration increases.

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Effects of viscoelasticity on shear-thickening in dilute suspensions in a viscoelastic fluid

Soft Matter ◽

10.1039/c9sm01736d ◽

2020 ◽

Vol 16 (3) ◽

pp. 728-737

Author(s):

Yuki Matsuoka ◽

Yasuya Nakayama ◽

Toshihisa Kajiwara

Keyword(s):

Numerical Simulation ◽

Direct Numerical Simulation ◽

Viscoelastic Fluid ◽

Shear Thickening ◽

Profile Method ◽

Fluid Elasticity ◽

Simulation Based ◽

Dilute Suspensions ◽

Smoothed Profile Method

We investigate previously unclarified effects of fluid elasticity on shear-thickening in dilute suspensions in an Oldroyd-B viscoelastic fluid using a novel direct numerical simulation based on the smoothed profile method.

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Kinetic theory of discontinuous rheological phase transition for a dilute inertial suspension

Progress of Theoretical and Experimental Physics ◽

10.1093/ptep/ptz075 ◽

2019 ◽

Vol 2019 (8) ◽

Cited By ~ 4

Author(s):

Hisao Hayakawa ◽

Satoshi Takada

Keyword(s):

Kinetic Theory ◽

Flow Curve ◽

Hard Spheres ◽

Shear Thickening ◽

Attractive Interaction ◽

Negative Slope ◽

Kinetic Temperature ◽

Dilute Suspensions ◽

Langevin Simulation ◽

Elastic Particles

Abstract A kinetic theory for a dilute inertial suspension under a simple shear is developed. With the aid of the corresponding Boltzmann equation, it is found that the flow curves (the relations between the stress and the strain rate) exhibit the crossovers from the Newtonian to the Bagnoldian for a granular suspension and from the Newtonian to a fluid having a viscosity proportional to the square of the shear rate for a suspension consisting of elastic particles, respectively. The existence of the negative slope in the flow curve directly leads to a discontinuous shear thickening (DST). This DST corresponds to the discontinuous transition of the kinetic temperature between a quenched state and an ignited state. The results of the event-driven Langevin simulation of hard spheres perfectly agree with the theoretical results without any fitting parameter. The introduction of an attractive interaction between particles is also another source of the DST in dilute suspensions. Namely, there are two discontinuous jumps in the flow curve if the suspension particles have the attractive interaction.

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Dynamic simulation of shear thickening in concentrated colloidal suspensions

Journal of Fluid Mechanics ◽

10.1017/s0022112097007167 ◽

1997 ◽

Vol 353 ◽

pp. 1-30 ◽

Cited By ~ 25

Author(s):

D. I. DRATLER ◽

W. R. SCHOWALTER ◽

R. L. HOFFMAN

Keyword(s):

Shear Rate ◽

Hard Spheres ◽

Shear Thickening ◽

Colloidal Suspensions ◽

System Size ◽

Linear Instability ◽

Computational Domain ◽

Stokesian Dynamics ◽

Rigid Spheres ◽

Critical Shear Rate

Stokesian Dynamics has been used to investigate the origins of shear thickening in concentrated colloidal suspensions. For this study, we considered a monolayer suspension composed of charge-stabilized non-Brownian monosized rigid spheres dispersed at an areal fraction of ϕa=0.74 in a Newtonian liquid. The suspension was subjected to a linear shear field. In agreement with established experimental data, our results indicate that shear thickening in this system is associated with an order–disorder transition of the suspension microstructure. Below the critical shear rate at which this transition occurs, the suspension microstructure consists of two-dimensional analogues of experimentally observed sliding layer configurations. Above this critical shear rate, suspensions are disordered, contain particle clusters, and exhibit viscosities and microstructures characteristic of suspensions of non-Brownian hard spheres. In addition, suspensions possessing the sliding layer microstructure at the beginning of supercritical shearing tend to retain this microstructure for a period of time before disordering. The onset of this disorder is due to the formation of particle doublets within the suspension. Once formed, these doublets rotate, due to the bulk motion, and disrupt the long-range order of the suspension. The cross-stream component of the centre-to-centre separation vector associated with the two particles forming a doublet, which is zero when the doublet is perfectly aligned with the bulk velocity vector, grows exponentially with time. This strongly suggests that the evolution of these doublets is due to a change in the stability of the sliding layer configurations, with this type of ordered microstructure being linearly unstable above a critical shear rate. This contention is supported by results of a stability analysis. The analysis shows that a single string of particles is subject to a linear instability leading to the formation of particle doublets. Simulations were repeated with different numbers of particles in the computational domain, with the results found to be qualitatively independent of system size.

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Shear thickening in filled Boger fluids

Journal of Rheology ◽

10.1122/1.1849185 ◽

2005 ◽

Vol 49 (2) ◽

pp. 551-567 ◽

Cited By ~ 33

Author(s):

Rossella Scirocco ◽

Jan Vermant ◽

Jan Mewis

Keyword(s):

Shear Thickening ◽

Boger Fluids

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Effects of Prostaglandins, Derivatives of Cyclic 3':5'-AMP, Theophylline, Cholinergic Agents and Colchicine on Clot Retraction in Dilute Platelet-Rich Plasma and Gel-Separated Platelet Test Systems

Thrombosis and Haemostasis ◽

10.1055/s-0038-1651477 ◽

1977 ◽

Vol 38 (02) ◽

pp. 0420-0428 ◽

Cited By ~ 1

Author(s):

J. L Moake ◽

P. L Cimo ◽

K Widmer ◽

D. M Peterson ◽

J. R Gum

Keyword(s):

Platelet Rich Plasma ◽

Inhibitory Effect ◽

Fibrin Clot ◽

Serotonin Release ◽

Dibutyryl Camp ◽

Clot Retraction ◽

Dilute Suspensions ◽

Cholinergic Agents ◽

Camp Levels ◽

Derivatives Of

SummaryIn dilute suspensions of platelet-rich plasma (PRP) or gel-separated platelets (GSP), dibutyryl-cAMP (DBcAMP) and monobutyryl-cAMP inhibited platelet-mediated fibrin clot retraction in concentrations of 2–3 × 10–6M, with complete inhibition at 1–3 × 10–4M. Prostaglandin E1 (PGE1), which inhibited fibrin clot retraction in concentrations greater than 1.5–3 × 10–8M, was a more effective inhibitor than either PGE2 or PGF2α. In the presence of theophylline (10–4M), concentrations of DBcAMP, PGE1 PGE2 and PGF2α necessary to inhibit fibrin clot retraction were reduced 50-fold for DBcAMP and 2.5 to 20-fold for the prostaglandins. In dilute PRP or GSP, inhibition of fibrin clot retraction does not result from inhibition of thrombin-induced platelet aggregation. Thus, compounds which increase platelet cAMP levels result in the inhibition of platelet-mediated fibrin clot retraction, and this inhibitory effect may be mediated, at least in part, through suppression of platelet contractility. Cyclic GMP, dibutyryl-cGMP and carbamylcholine-Cl (which stimulates guanylate cyclase) did not influence fibrin clot retraction, and did not prevent inhibition of fibrin clot retraction by DBcAMP and PGE?. Colchicine, in concentrations known to disrupt platelet microtubules (2.5 × 10–6M to 2.5 x 10–3M), had little inhibitory effect on either fibrin clot retraction or platelet (3H)-serotonin release.

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Structure of a shear-thickening polysaccharide extracted from the New Zealand black tree fern, Cyathea medullaris

10.26686/wgtn.12597809.v1 ◽

2020 ◽

Author(s):

M Wee ◽

M Mastrangelo ◽

Susan Carnachan ◽

Ian Sims ◽

K Goh

Keyword(s):

New Zealand ◽

Uronic Acid ◽

Average Molecular Weight ◽

Shear Thickening ◽

Water Soluble ◽

Size Exclusion ◽

Resonance Spectroscopy ◽

Tree Fern ◽

13C Nuclear Magnetic Resonance ◽

Exclusion Chromatography

A shear-thickening water-soluble polysaccharide was purified from mucilage extracted from the fronds of the New Zealand black tree fern (Cyathea medullaris or 'mamaku' in Māori) and its structure characterised. Constituent sugar analysis by three complementary methods, combined with linkage analysis (of carboxyl reduced samples) and 1H and 13C nuclear magnetic resonance spectroscopy (NMR) revealed a glucuronomannan comprising a backbone of 4-linked methylesterified glucopyranosyl uronic acid and 2-linked mannopyranosyl residues, branched at O-3 of 45% and at both O-3 and O-4 of 53% of the mannopyranosyl residues with side chains likely comprising terminal xylopyranosyl, terminal galactopyranosyl, non-methylesterified terminal glucopyranosyl uronic acid and 3-linked glucopyranosyl uronic acid residues. The weight-average molecular weight of the purified polysaccharide was ~1.9×106Da as determined by size-exclusion chromatography coupled with multi-angle laser light scattering (SEC-MALLS). The distinctive rheological properties of this polysaccharide are discussed in relation to its structure. © 2014 Elsevier B.V.

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