Experimental measurements of the normal stresses in sheared Stokesian suspensions

Singh, Anugrah; Nott, Prabhu R.

doi:10.1017/s0022112003005366

Cited by 113 publications

(109 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The second normal stress difference |N 2 | is found to be larger than |N 1 | with N 2 /N 1 ⇡ 3.6. Later measurements by Singh & Nott (2003) using similar devices have confirmed that N 1 and N 2 are both negative but with a ratio N 2 /N 1 which depends on φ. Dai et al (2013) used a combination of a parallelplate rheometer and the open semi-circular trough method to measure N 1 and N 2 .T h e y found a good agreement with previous works with negative normal stress differences and |N 1 |⌧| N 2 |.…”

Section: Introductionmentioning

confidence: 84%

Rheology of sheared suspensions of rough frictional particles

et al. 2014

View full text Add to dashboard Cite

This paper presents three-dimensional numerical simulations of non-Brownian concentrated suspensions in a Couette flow at zero Reynolds number using a fictitious domain method. Contacts between particles are modelled using a discrete element method (DEM)-like approach, which allows for a more physical description, including roughness and friction. This work emphasizes the effect of friction between particles and its role on rheological properties, especially on normal stress differences. Friction is shown to notably increase viscosity and second normal stress difference $\def \xmlpi #1{}\def \mathsfbi #1{\boldsymbol {\mathsf {#1}}}\let \le =\leqslant \let \leq =\leqslant \let \ge =\geqslant \let \geq =\geqslant \def \Pr {\mathit {Pr}}\def \Fr {\mathit {Fr}}\def \Rey {\mathit {Re}}|N_2|$ and decrease $|N_1|$, in better agreement with experiments. The hydrodynamic and contact contributions to the overall particle stress are particularly investigated. This shows that the effect of friction is mostly due to the additional contact stress since the hydrodynamic stress remains unaffected by friction. Simulation results are also compared with experiments, such as normal stresses or effective friction coefficient $\mu (I_v)$, and the agreement is improved when friction is accounted for. This suggests that friction is operative in actual suspensions.

show abstract

Section: Introductionmentioning

confidence: 84%

Rheology of sheared suspensions of rough frictional particles

et al. 2014

View full text Add to dashboard Cite

show abstract

“…Several previous studies [11][12][13][14][15][16] have attempted to determine parts of the particle phase stress by experiment, simulation, or analysis, by equating ͗ h ͘ p with ⌺ h͑p͒ . In view of our result, their results and interpretations are at least partly in error.…”

Section: Introductionmentioning

confidence: 99%

“…͑1͒-what they actually measured is a part of the suspension pressure. Indeed, Singh and Nott 16 realized that they could not determine the particle phase pressure from rheological measurements of the suspension. The normal stress differences measured by simulation 13,15 and experiment 14,16 are useful viscometric properties of the suspension.…”

Section: Introductionmentioning

confidence: 99%

“…Indeed, Singh and Nott 16 realized that they could not determine the particle phase pressure from rheological measurements of the suspension. The normal stress differences measured by simulation 13,15 and experiment 14,16 are useful viscometric properties of the suspension. Nott and Brady 2 saw the possibility of normal stress differences of the particle phase modulating particle migration in curvilinear flows, which was shown more clearly by Morris and Boulay 18 using proposed functional forms for the normal stress differences.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The suspension balance model revisited

Nott¹,

Guazzelli²,

Pouliquen³

2011

Physics of Fluids

Self Cite

119

View full text Add to dashboard Cite

This paper addresses a fundamental discrepancy between the suspension balance model and other two-phase flow formulations. The former was proposed to capture the shear-induced migration of particles in Stokesian suspensions, and hinges on the presence of a particle phase stress to drive particle migration. This stress is taken to be the "particle stress," defined as the particle contribution to the suspension stress. On the other hand, the two-phase flow equations derived in several studies show only a force acting on the particle phase, but no stress. We show that the identification of the particle phase stress with the particle contribution to the suspension stress in the suspension balance model is incorrect, but there exists a well-defined particle phase stress. Following the rigorous method of volume averaging, we show that the force on the particle phase may be written as the sum of an interphase drag and the divergence of the particle phase stress. We derive exact micromechanical relations for these quantities. We also comment on the interpretations and results of previous studies that are based on the identification of the particle phase stress with the particle contribution to the suspension stress.

show abstract

“…Using these non conventional rheological tools (rotating-rod and tiltedtrough), the value is found too close to zero to determine whether it is negative, positive or null within experimental accuracy. Some experiments using more conventional rheometry find that N 1 is quite small and negative [10][11][12][13], while others report positive values [14]. Some recent studies point to the effect of polydispersity [15] and of confinement [16] which may explain these discrepancies.…”

Section: Suspension Viscositymentioning

confidence: 99%

Rheology of dense suspensions of non colloidal particles

Guazzelli

2017

EPJ Web Conf.

View full text Add to dashboard Cite

Abstract. Dense suspensions are materials with broad applications both in industrial processes (e.g. waste disposal, concrete, drilling muds, metalworking chip transport, and food processing) and in natural phenomena (e.g. flows of slurries, debris, and lava). Despite its long research history and its practical relevance, the mechanics of dense suspensions remain poorly understood. The major difficulty is that the grains interact both by hydrodynamic interactions through the liquid and by mechanical contact. These systems thus belong to an intermediate regime between pure suspensions and granular flows. We show that we can unify suspension and granular rheology under a common framework by transferring the frictional approach of dry granular media to wet suspensions of spherical particles. We also discuss non-Newtonian behavior such as normal-stress differences and shear-induced migration. Beyond the classical problem of dense suspension of hard spheres which is far from being completely resolved, there are also entirely novel avenues of study concerning more complex mixtures of particles and fluids such as those involving other types of particles (e.g. fibers) or non-Newtonian fluids that we will also address.

show abstract

Experimental measurements of the normal stresses in sheared Stokesian suspensions

Cited by 113 publications

References 14 publications

Rheology of sheared suspensions of rough frictional particles

Rheology of sheared suspensions of rough frictional particles

The suspension balance model revisited

Rheology of dense suspensions of non colloidal particles

Contact Info

Product

Resources

About